We provide electrostatic potential and capacitance practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on electrostatic potential and capacitance skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.
List of electrostatic potential and capacitance Questions
| Question No | Questions | Class |
|---|---|---|
| 1 | If charge density of an infinite charged plate is doubled and the distance of point charge is tripled from the infinite charged plate, then electric field is increased ( _{text {thes }} ) |
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| 2 | A capacitors has square plates each of side ( l ) making an angle a with each other as shown in the figure. Then, for small value of a the capacitance ( C ) is given by : ( ^{mathbf{A}} cdot frac{epsilon_{0} I^{2}}{d}left(1-frac{a l}{2 d}right) ) В ( cdot frac{epsilon_{0} I^{2}}{2 d}left(1-frac{a l}{d}right) ) c. ( frac{epsilon_{0} I^{2}}{d}left(1-frac{a l}{d}right) ) D ( cdot frac{epsilon_{0} I^{2}}{2 d}left(1+frac{a l}{d}right) ) |
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| 3 | Consider a system of three charges ( frac{mathbf{q}}{mathbf{3}} ) ( frac{mathbf{q}}{mathbf{3}} ) and ( -frac{mathbf{2 q}}{mathbf{3}} ) placed at points ( mathbf{A}, mathbf{B} ) and C, respectively, as shown in the figure. Take 0 to be the centre of the circle of radius ( mathbf{R} ) and angle ( mathbf{C A B}=mathbf{6 0}^{mathbf{0}} ) A ( cdot ) The electric field at point ( mathrm{O} ) is ( frac{mathrm{q}}{8 pi epsilon_{0} mathrm{R}^{2}} ) directed along the negative x-axis B. The potential energy of the system is zero C. The magnitude of the force between the charges at ( C ) and ( mathrm{B} ) is ( frac{mathrm{q}^{2}}{54 pi epsilon_{0} mathrm{R}^{2}} ) D. The potential at point ( mathrm{O} ) is ( frac{mathrm{q}}{12 pi epsilon_{0} mathrm{R}} ) |
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| 4 | An uncharged capacitor of capacitance ( 4 mu F, ) a battery of emf 12 volt and a resistor of ( 2.5 ~ M Omega ) are connected in series. The time after which ( v_{c} ) ? ( 3 v_{R}=0.693 ) A. 6.93 sec B. ( 13.86 mathrm{sec} ) c. ( 20.52 mathrm{sec} ) D. none of these |
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| 5 | Assertion The force between two electric charges in a dielectric medium is less than it would be in a vacuum. Reason Quantity of energy stored in an electric field per unit volume of a dielectric medium is greater than that of vaccum A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 6 | When a charge of amount ( Q ) is given to an isolated metal plate ( X ) of surface area ( A, ) its surface charge density becomes ( sigma_{1} . ) When an isolated identical plate ( Y ) is brought close to ( X, ) the surface charge density on X becomes ( sigma_{2} . ) When ( y ) is earthed, the surface charge density becomes ( sigma_{3} ) This question has multiple correct options A ( cdot sigma_{1}=frac{Q}{A} ) В. ( sigma_{1}=frac{Q}{2 A} ) ( mathbf{C} cdot sigma_{1}=sigma_{2} ) D. ( _{sigma_{3}}=frac{Q}{A} ) |
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| 7 | Complete the following statements with an appropriate word /term be filled in the blank space(s).
The equivalent capacitance ( C ) for the parallel combination of three |
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| 8 | Calculate the change in potential energy of a particle of charge ( +boldsymbol{q} ) that is brought from a distance of ( 3 r ) to a distance of ( 2 r ) in the electric field of charge ( -q ? ) ( mathbf{A} cdot k q^{2} / r ) B ( .-k q^{2} / 6 r ) c. ( k q^{2} / 4 r^{2} ) D. ( -k q^{2} / 4 r^{2} ) E . ( k q^{2} / r^{2} ) |
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| 9 | Why is the potential inside a hollow spherical charged conductor, constant and has the same value as on its surface ? |
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| 10 | Two charges ( q_{1}=12 times 10^{-9} mathrm{C} ) and ( q_{2}= ) ( -12 times 10^{-9} C ) are placed ( 10 c m ) apart. The potential at a point ( 6 mathrm{cm} ) from ( q_{1} ) on the line joining the two charges is : A. 3500 Volt B. 900 Volt c. ( 1800 V ) olt D. -900 Volt |
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| 11 | A charged particle having a charge of ( -2 times 10^{-6} C ) is placed close to a non conducting plate having a surface charge density as ( 4 times 10^{-6} mathrm{Cm}^{-2} . ) What will be the force of attraction between them: A . ( 0.5 N ) B. ( 0.45 N ) c. ( 0.25 N ) ( D ldots .0 .75 N ) |
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| 12 | A positive charge and a negative charge are held in place and initially form a dipole. Then a uncharged conducting bar is placed in between them. How is the force between the charges |
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| 13 | A cloud is at a potential of ( 8 times 10^{9} V ) relative to the ground. A charge of ( 40 C ) is transferred in a lightning stroke between the cloud and the earth. The energy released is: A ( cdot 3.2 times 10^{11} J ) B . ( 5 times 10^{9} J ) c. ( 2 times 10^{9} J ) D. ( 32 times 10^{12} J ) |
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| 14 | A cloud carries a charge of 1000 C at a potential of ( 5 mathrm{kV} ). If the cloud discharge, the amount of energy released: A ( .5 times 10^{6} J ) В. ( 2.5 times 10^{6} J ) ( c cdot 10^{7} J ) D ( .5 times 10^{3} J ) |
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| 15 | mass ( m ) carrying charge ( q . ) The bead can freely move on the smooth fixed ring placed on a smooth horizontal plan. In the same plane a charge ( +Q ) has also been fixed as shown. The potential at the point ( boldsymbol{P} ) due to ( +boldsymbol{Q} ) is ( boldsymbol{V} ). The velocity with which the bead should projected from the point ( P ) so that it can complete a circle should be greater than A ( cdot sqrt{frac{6 q V}{m}} ) B. ( sqrt{frac{q V}{m}} ) c. ( sqrt{frac{3 q V}{m}} ) D. nont |
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| 16 | Fill in the blank. The electric potential ( V ) at any point ( x, y, z ) (all in meters) in space is given by ( V=4 x^{2} ) volts. The electric field at the point ( (1 m, 0,2 m) ) is ( _{—–} V / m ) |
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| 17 | What is not true of equipotential surface? A. The PD between any two points on the surface is zero B. The electric field is always perpendicular to the surface C. Equipotential surfaces are always spherical D. No work is done in moving a charge along the surface |
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| 18 | What is the area of the plates of a 2 F parallel plate capacitor, given that the separation between the plates is 0.5 ( mathrm{cm} ?[ ) You will realise from your answer why ordinary capacitors are in the range of F or less. However, electrolytic capacitors do have a much larger capacitance (0.1 ( F ) ) because of very minute separation between the conductors. |
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| 19 | Among identical spheres ( A ) and ( B ) having charges ( -15 C ) and ( -16 C: ) A. ( -15 C ) is at higher potential B. ( -16 C ) is at higher potential c. both are at equal potential D. no such comparison can be made |
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| 20 | In an uniform electric field ( boldsymbol{E}=mathbf{1 0} boldsymbol{N} / boldsymbol{C} ) as shown in figure, find ( V_{B}-V_{C}: ) ( mathbf{A} cdot 10 V ) B. ( -10 V ) ( mathbf{c} cdot 20 V ) D ( .-20 V ) |
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| 21 | A conductor with a cavity is charged positively and its surface charge density is ( sigma . ) If ( E ) and ( V ) represent the electric field and potential, then inside the cavity: ( mathbf{A} cdot ) and ( V=0 ) B. ( E=0 ) and ( V=0 ) c. ( E=0 ) and ( sigma= ) constant D. ( V=0 ) and ( sigma= ) constant E . ( E=0 ) and ( V= ) constant |
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| 22 | An ellipsoidal cavity is carved within a perfect conductor. A positive charge q is placed at the centre of the cavity. The points ( A ) and ( B ) are on the cavity surfaces as shown in the figure. Then This question has multiple correct options A. Electric field near A in the cavity = Electric field near B in the cavity B. Charge density at A = charge density at B c. Potential at ( A= ) potential at ( B ) D. Total electric flux through the surface of the cavity is ( q / epsilon_{0} ) |
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| 23 | If metal section of shape H is inserted in between two parallel plates as shown in figure and ( A ) is the area of each plate then the equivalent capacitance is : A ( cdot frac{A epsilon_{0}}{a}-frac{A epsilon_{0}}{b} ) В. ( frac{A epsilon_{0}}{a+b} ) c. ( frac{A epsilon_{0}}{a}+frac{A epsilon_{0}}{b} ) D. ( frac{A epsilon_{0}}{a-b} ) |
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| 24 | A conducting sphere of radius ( mathrm{R} ) is given a charge ( Q . ) The electric potential and the electric field at the centre of the sphere respectively are : A ( cdot ) zero and ( frac{Q}{4 pi epsilon_{0} R^{2}} ) в. ( frac{Q}{4 pi epsilon_{0} R} ) and zerc c. ( frac{Q}{4 pi epsilon_{6} R} ) and ( frac{Q}{4 pi epsilon_{0} R^{2}} ) D. Both are zero |
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| 25 | In above shown figure, the two plates of the capacitor of charge ( +mathrm{Q} ) and ( -mathrm{Q}, ) which points lie on the same equipotential? ( A cdot 1 ) and 2 only B. 1 and 3 only C. 2 and 4 only D. 3 and 4 only E. ( 1,2,3, ) and 4 all lie on the same equipotential, since the electric field is uniform |
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| 26 | If a slab of insulating material ( 4 times ) ( 10^{-5} m ) thick is introduced between the plates of a parallel plate capacitor, the distance between the plates has to be increased by ( 3.5 times 10^{-5} m ) to restore the capacity to original value. Then the dielectric constant of the material of slab is : ( A cdot 8 ) B. 6 c. 12 D. 10 |
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| 27 | A capacitor of capacitance ( 2 mu F ) is charged to a voltage of ( 6 mathrm{V} ). The charge on its plates is: A . ( 1.2 times 10^{-5} C ) B . ( 3 times 10^{-6} C ) c. ( frac{1}{3} times 10^{-6} C ) D. ( frac{1}{12} times 10^{-6} mathrm{C} ) |
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| 28 | Q Type your question Nưe: points at infinite distance from the spheres)? The diagram shows two spheres, charged uniformly as indicated. All regions are along a line connecting the centers of the objects. Region ( A ) is anywhere to the left of the 5.0 Coulomb charge. Region B is to the right of the 5.0 Coulomb charge and closer to the 5.0 Coulomb charge than to the 3.0 Coulomb charge. Region ( C ) is to |
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| 29 | In a region, uniform electric field exists as ( overrightarrow{boldsymbol{E}}=[mathbf{1 0 hat { boldsymbol { i } }}+mathbf{1 0 hat { boldsymbol { j } }}] boldsymbol{N} / boldsymbol{C} . ) If the potential of origin is 0 volts, the potential of point ( (10 m, 10 m, 10 m) ) |
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| 30 | Two capacitors of capacity ( C_{1} ) and ( C_{2} ) are connected in parallel, then the equivalent capacity is: A ( cdot C_{1}+C_{2} ) в. ( C_{1} C_{2} /left(C_{1}+C_{2}right) ) c. ( C_{1} / C_{2} ) D. ( C_{2} / C_{1} ) |
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| 31 | A parallel plate capacitor has plates with area ( A & ) separation ( d . A ) battery charges the plates to a potential difference of ( V_{0} . ) The battery is then disconnected & a di-electric slab of constant ( K & ) thickness ( d ) is introduced. Calculate the positive work done by the system (capacitor ( + ) slab) on the man who introduces the slab. |
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| 32 | A parallel plate capacitor has two square plates with equal and opposite charges. The surface charge densities on the plate are ( +sigma ) and ( -sigma ) respectively. In the region between the plates the magnitude of electric field is: A ( cdot frac{sigma}{2 varepsilon_{0}} ) в. ( frac{sigma}{varepsilon_{0}} ) ( c cdot 0 ) D. none of these |
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| 33 | A hollow conducting spherical shell of radius ( R ) is charged with ( Q ) coulomb. The amount of work done for moving any charge ( q ) from the centre to the surface of the shell will be A ( cdot frac{q Q}{4 pi epsilon_{0} R} ) B. Zero c. ( frac{Q q}{pi epsilon_{0} R} ) D ( frac{2 Q q}{pi epsilon_{0} R} ) |
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| 34 | The work done in placing a charge of ( 8 times 10^{-18} ) coulomb on a condenser of capacity 100 micro-farad is: A ( cdot 16 times 10^{-32} ) joule B. ( 3.2 times 10^{-26} ) joule C ( cdot 4 times 10^{-10} ) joule D. ( 32 times 10^{-32} ) joule |
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| 35 | Two capacitors of ( 0.5 mu F ) and ( 1 mu F ) are connected in parallel across a battery. If the charge on ( 0.5 mu F ) is ( 50 mu C ), the charge on the other capacitor is : A. ( 100 mu C ) B. ( 50 mu C ) c. ( 25 mu C ) D. zero |
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| 36 | There are two concentric spherical shells of radii ( r ) and ( 2 r . ) Initially a charge ( Q ) is given to the inner shell and both the switches are open. Now ( S_{2} ) is closed and opened, The charge flowing through the switch ( S_{2} ) in the process is A. ( Q ) в. ( frac{Q}{4} ) ( c cdot frac{Q}{2} ) D. ( frac{2 Q}{3} ) |
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| 37 | A dipole of dipole moment ( overrightarrow{boldsymbol{p}} ) is kept along an electric field ( overrightarrow{boldsymbol{E}} ) such that ( overrightarrow{boldsymbol{E}} ) and ( vec{p} ) are in the same direction. Find the work done in rotating the dipole by an angle ( pi ) A. ( W=3 E p ) в. ( W=2 E p ) c. ( W=4 ) Ер. D. ( W=5 E p ) |
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| 38 | In a parallel plate capacitor, the capacitance: A. increases with increase in the distance between the plates B. decreases if a dielectric material is put between the plates C. increases with decrease in the distance between the plates D. increases with decrease in the area of the plates |
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| 39 | Two identical thin rings, each of radius 10cm carrying charges ( 10 C ) and ( 5 C ) are coaxially placed at a distance ( 10 mathrm{cm} ) a part. The work done in moving a charge ( q ) from the centre of the first ring to that of the second is A ( cdot frac{q}{8 pi varepsilon_{0}}left(frac{sqrt{2}+1}{sqrt{2}}right) ) В. ( frac{q}{8 pi varepsilon_{0}}left(frac{sqrt{2}-1}{sqrt{2}}right) ) c. ( frac{q}{4 pi varepsilon_{0}}left(frac{sqrt{2}+1}{sqrt{2}}right) ) D. ( frac{q}{4 pi varepsilon_{0}}left(frac{sqrt{2}-1}{sqrt{2}}right) ) E ( cdot frac{q}{4 pi varepsilon_{0}}left(frac{sqrt{3}+1}{sqrt{2}}right) ) |
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| 40 | When a metal plate is introduced between the two plates of a charged capacitor and insulated from them, then This question has multiple correct options A. the metal plate divides the capacitor into two capacitors connected in parallel to each other B. the metal plate divides the capacitor into two capacitors connected in series with each other C. the metal plate is equivalent to a dielectric of zero dielectric constant D. the metal plate is equivalent to a dielectric of infinite dielectric constant |
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| 41 | Figure shows three points ( A, B ) and ( C ) in a region of uniform electric field ( vec{E} ). The line ( A B ) is perpendicular and ( B C ) is parallel to the field lines. Then which of the following holds good. Here ( boldsymbol{V}_{boldsymbol{A}}, boldsymbol{V}_{boldsymbol{B}} ) and ( V_{C} ) represents the electric potential at point ( A, B ) and ( C ) respectively. ( mathbf{A} cdot V_{A}=V_{B}=V_{C} ) B ( cdot V_{A}=V_{B}>V_{C} ) ( mathbf{c} cdot V_{A}=V_{B}V_{B}=V_{C} ) |
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| 42 | A ( 10 mu F ) capacitor is connected across a ( 200 V, 50 H z ) A.C. supply. The peak current through the circuit is : A. ( 0.6 A ) в. ( 0.6 sqrt{2} A ) D. ( 0.6 pi A ) |
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| 43 | A large insulated sphere of radius ( r ) charged with ( Q ) units of electricity is placed in contact with a small insulated uncharged sphere of radius ( r^{prime} ) and is then separated. The charge on the smaller sphere will now be: A ( cdot frac{Qleft(r^{prime}+rright)}{r^{prime}} ) в. ( frac{Qleft(r^{prime}+rright)}{r} ) c. ( frac{Q r}{left(r^{prime}+rright)} ) D. ( frac{Q_{r}^{prime}}{left(r^{prime}+rright)} ) |
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| 44 | n the given circuit, find the potential difference across the 6 ( mu ) F capacitor in steady state 4.4 3.22 ( c cdot 6 v ) D |
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| 45 | Consider the figure given. Each capacitor has capacitance ( C . ) The capacitance between 1 and 3 is : ( A cdot frac{3 C}{4} ) B. ( frac{3 C}{2} ) ( c cdot frac{5 C}{2} ) D. ( frac{50}{1} ) |
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| 46 | Two tiny spheres carrying charges 1.8 ( mu C ) and ( 2.8 mu C ) are located at ( 40 mathrm{cm} ) apart. The potential at the mid-point of the line joining the two charges is A ( cdot 3.8 times 10^{4} v ) B . ( 2.1 times 10^{5} mathrm{v} ) c. ( 4.3 times 10^{4} v ) D. 3.6 ( times 10^{5} mathrm{v} ) |
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| 47 | A parallel plate capacitor is charged and then isolated. The effect of increasing the plate separation on charge, potential and capacitance respectively are: A. constant, decreases, decreases B. increases, decreases, decreases c. constant, decreases, increases D. constant, increases, decreases |
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| 48 | Three charges ( Q,+q ) and ( +q ) are placed at the vertices of a right angle isosceles triangle as shown. The net electrostatic energy of the configuration is zero, if ( boldsymbol{Q} ) is equal to: ( mathbf{A} ) B. ( mathbf{c} .-2 q ) D. ( +q ) |
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| 49 | 1 V equals: A . 1 J B. ( 1 mathrm{JC}^{-1} ) ( c cdot 1 C J^{-1} ) D. 1 JC |
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| 50 | Which one of the following gives the resultant capacitor when capacitors are joined in series? A. The sum of the individual capacitors B. The reciprocal of the sum of the reciprocals of the individual capacitors c. The reciprocal of the sum of the capacitors D. The sum of the reciprocals of the individual capacitors |
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| 51 | Which of the following statement are true? A. Charge ( q_{3} ) applies a large force on charge ( q_{2} ) than on charge ( q_{1} ) B. Charge ( q_{3} ) applies a smaller force on charge ( q_{2} ) than on charge ( q_{1} ) C. Charge ( q_{3} ) applies equal force on bothy the charges. D. Charge ( q_{3} ) applies no force on any of the charges. |
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| 52 | If the charge of ( 10 mu C ) and ( -2 mu C ) are given to two plates of a capacitor which are connected across a battery of ( 12 V ) find the capacitance of the capacitor. в. ( 0.5 mu F ) c. ( 0.41 mu F ) D. ( 0.66 mu F ) |
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| 53 | The value of equivalent capacitance of the combination shown in figure, between the points ( boldsymbol{P} ) and ( boldsymbol{Q} ) is A. ( 3 C ) B. ( 2 C ) ( c . C ) D. ( C / 3 ) |
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| 54 | The work done in carrying in point charge from one point to the another in an electrostatic field depends on the path along which the point charge is carried A. True B. False |
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| 55 | Two points charges placed at a distance ( r, ) in the air experience a certain force then the distance at which they will experience the same force in the medium off dielectric constant K is A. ( K r ) в. ( frac{r}{K} ) c. ( frac{r}{sqrt{K}} ) D. ( r sqrt{K} ) |
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| 56 | Two identical capacitors are joined in parallel and charged to a potential ( V ) Capacitors are separated and then connected in series, i.e., the positive plate of one is connected to the negative plate of other. Identify the correct option: A. The charges on the free plates are enhanced. B. The charges on the free plates decrease. c. The energy stored in the system increase D. The potential difference between the free plates is ( 2 V ) |
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| 57 | How much work would be required to move a proton from the negative to the positive plate? A. ( -3.6 times 10^{-18} J ) в. ( 3.6 times 10^{-19} mathrm{J} ) c. ( 3.6 times 10^{-18} mathrm{J} ) D. ( -3.6 times 10^{-19} mathrm{J} ) |
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| 58 | Two equal point charges are fixed at ( x=-a ) and ( x=+a ) on the ( X- ) axis Another point charge ( Q ) is placed at the origin. The change in electrical potential energy ( Q ) when it is displaced by a smal distance ( x ) along the ( X ) -axis, is approximately proportional to ( A cdot x ) в. ( x^{2} ) c. ( x^{3} ) D. ( 1 / x ) |
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| 59 | If dielectric is inserted in charged capacitor (battery removed), then quantity that remains constant is. A. Capacitance B. Potential c. Intensity D. charge |
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| 60 | Find the equivalent capacitance between the point ( A ) and ( B ) in given figure where ( boldsymbol{C}=mathbf{5} boldsymbol{mu} boldsymbol{F} ) |
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| 61 | A spherical capacitor has an inner sphere of radius ( 12 mathrm{cm} ) and an outer sphere of radius ( 13 mathrm{cm} . ) The outer sphere is earthed and the inner sphere is given a charge of ( 2.5 mu C . ) The space between the concentric spheres is filled with a liquid of dielectric constant 32 (a) Determine the capacitance of the capacitor. (b) What is the potential of the inner sphere? (c) Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller. |
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| 62 | A metal sphere of radius a is having charge ( +Q ) on it Now it is connected with a metal wire to a concentric spherica shell of radius 2 a Then the net potential at the surface of outer shell is ( ^{A} cdot frac{K Q}{a} ) в. ( frac{K Q}{2 a} ) c. ( frac{3}{2} frac{K Q}{a} ) D. ( frac{2 K Q}{a} ) |
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| 63 | A ( 500 mu F ) capacitor is charged at a steady rate of ( 100 mu C / ) sec. The potential difference across the capacitor will be ( 10 V ) after an interval of ( mathbf{A} cdot 5 ) sec B. 20 sec c. 25 sec D. 50 sec |
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| 64 | The potential difference between point B and ( mathrm{C} ) of the circuit is A ( cdot frac{left(C_{2}-C_{1}right)}{V} ) B. ( frac{left(C_{4}-C_{3}right)}{V} ) c. ( frac{left(C_{2} C_{3}-C_{1} C_{4}right)}{left(C_{1}+C_{2}+C_{3}+C_{4}right)} cdot V ) D. ( frac{C_{1} C_{4}-C_{2} C_{3}}{left(C_{1}+C_{2}right) timesleft(C_{3}+C_{4}right)} cdot V ) |
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| 65 | The dielectric strength of air is ( 3 times 10^{6} v ) ( / mathrm{m} . ) A parallel plate air capacitor has ( operatorname{area} 20 c m^{2} ) and plate separation ( 1 mathrm{mm} ) Then maximum r.m.s. voltage of an A.C. source which can be safely connected to this capacitor is A . 212.2 B. 21.22 c. ( 2.122 mathrm{v} ) D. 2122 V |
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| 66 | The gap between the plates of a parallel plate capacitor of area ( A ) and distance between plates ( d ), is filled with a dielectric whose permittivity varies linearly from ( epsilon_{1} ) at one plate to ( epsilon_{2} ) at the other. The capacitance of capacitor is : ( mathbf{A} cdot epsilon_{0}left(epsilon_{1}+epsilon_{2}right) A / d ) В ( cdot epsilon_{0}left(epsilon_{2}+epsilon_{1}right) A / 2 d ) ( mathbf{c} cdot epsilon_{A} / dleft[d ln left(epsilon_{2} / epsilon_{1}right)right] ) D. ( epsilon_{0}left(epsilon_{2}-epsilon_{1}right) A /left[d l nleft(epsilon_{2} / epsilon_{1}right)right] ) |
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| 67 | f the electric potential of the inner shell is ( 10 V ) and that of the outer shell is ( 5 V ) then the potential at the centre will be ( 4.10 V ) ( 3.5 V ) ( c .15 V ) D |
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| 68 | Write a relation for polarisation ( vec{P} ) of ( a ) dielectric material in the presence of an external electric field ( vec{E} ). | 12 |
| 69 | A parallel plate capacitor is to be designed with a voltage rating ( 1 k V ) using a material of dielectric constant 10 and dielectric strength ( 10^{6} V m^{-1} ) What minimum area of the plates is required to have a capacitoance of ( 88.5 p F ? ) |
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| 70 | A parallel plate capacitor is connected to a battery. The quantities charge, voltage, electric field and energy associated with this capacitor are given by ( Q_{0}, V_{0}, E_{0}, ) and ( U_{0} ) respectively. ( A ) dielectric slab is now introduced to fill the space between the plates with the battery still in connection. The corresponding quantities now given by ( Q, V, E ) and ( U ) are related to the previous ones are : A ( cdot Q>Q_{0} ) в. ( V>V_{0} ) c. ( E>E_{0} ) D. ( U<U_{0} ) |
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| 71 | Two charges ( 5 times 10^{-8} C ) and ( -3 x ) ( 10^{-8} C ) are located ( 16 mathrm{cm} ) apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero. A. ( 20 mathrm{cm} ) away from the positive charge on the side of negative charge B. ( 40 mathrm{cm} ) away from the negative charge on the side of positive charge c. ( 40 mathrm{cm} ) away from the positive charge on the side of negative charge D. ( 20 mathrm{cm} ) away from the negative charge on the side of positive charge |
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| 72 | Find the potential energy to a system of four particles placed at the vertices of a square of side ( l ). Also obtain the potential at the centre of the square |
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| 73 | A parallel-plate capacitor is connected to a battery. A metal sheet of negligible thickness is placed between the plates. The sheet remains parallel to the plates of the capacitor. It’s capacitance will: A. Increase B. Decrease c. Remains the same D. Becomes infinite |
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| 74 | Two capacitors of capacity ( C_{1} ) and ( C_{2} ) are connected in parallel, then the equivalent capacity is: A ( cdot C_{1}+C_{2} ) в. ( C_{1} C_{2} /left(C_{1}+C_{2}right) ) c. ( C_{1} / C_{2} ) D. ( C_{2} / C_{1} ) |
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| 75 | ( n ) capacitors each of capacitance ( 2 mu F ) are connected in parallel and a potential difference of ( 200 mathrm{V} ) is applied to the combination. The total charge on all the positive plates is 1 Coulomb then ( n ) is equal to : A . 3333 в. 3000 ( c .2500 ) D. 25 |
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| 76 | The potential across a 25.0 microfarad capacitor is ( 5.0 mathrm{V} ). What is the charge on the capacitor? A. 0.20 microcoulombs B. 5.0 microcoulombs c. 125 microcoulombs D. 30.0 microcoulombs E. we cannot determine the charge on the capacitor with the given information. |
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| 77 | ( 2 mu F ) capacitance has P.D across its two terminals of ( 200 mathrm{V} . ) It is disconnected from the battery and when another uncharged capacitance is connected in parallel to it, P.D becomes 20 V. The capacity of another capacitance will be: A ( .2 mu F ) в. ( 4 mu F ) c. ( 10 mu F ) ( mathbf{D} cdot 16 mu F ) |
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| 78 | The capacity of a parallel plate condenser is ( 10 mu F, ) when the distance between its plates is ( 8 mathrm{cm} ). If the distance between the plates is reduced to ( 4 mathrm{cm}, ) then the capacity of this parallel plate condenser will be : A ( .5 mu F ) B. ( 10 mu F ) c. ( 20 mu F ) D. ( 40 mu F ) |
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| 79 | An air-gap parallel plate capacitor is fully charged by a battery. What combination of two measurements will allow someone to calculate the magnitude of the electric field in between the capacitor plates? A. The potential difference of the battery and the area of the plates. B. The charge on the plates and the distance between the plates. C. The charge on the plates and the area of the plates. D. The area of the plates and the distance between the plates E. More than two measurements are needed to calculate the electric field in between the capacitor plates. |
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| 80 | The potential at a point due to a charge of ( 5 times 10^{-7} C ) located ( 10 c m ) away is: A ( cdot 3.5 times 10^{5} V ) B . ( 3.5 times 10^{4} V ) c. ( 4.5 times 10^{4} V ) D. ( 4.5 times 10^{5} V ) |
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| 81 | A square loop ABCD, carrying a current ( I_{2}, ) is placed near and coplanar with a long straight conductor XY carrying a current ( I_{1}, ) as shown in the figure. The net force on the loop will be : A ( cdot frac{mu_{0} I_{1} I_{2}}{2 pi} ) В. ( frac{mu_{0} I_{1} I_{2} L}{2 pi} ) c. ( frac{2 mu_{0} I_{1} I_{2} L}{3 pi} ) D. ( frac{2 mu_{0} I_{1} I_{2}}{3 pi} ) |
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| 82 | A long, hollow conducting cylinder is kept coaxially inside another long, hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral A. A potential difference appears between the two cylinders when a charge density is given to the inner cylinder B. A potential difference appears between the two cylinders when a charge density is given to the outer cylinder c. No potential difference appears between the two cylinders when a uniform line charge is kept along the axis of the cylinders. D. No potential difference appears between the two cylinders when same charge density is given to both the cylinders. |
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| 83 | toppr Q Type your question smaller sphere with a large amount of negative charge. The differences in color for the larger Which of the following tables best |
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| 84 | A capacitor of ( 10 mu F ) is connected to a ( mathbf{1 0} boldsymbol{V} ) cell. The maximum charge on the capacitor will be: A. ( 1 mu C ) B. ( 10 mu C ) c. ( 100 mu C ) D. ( 1000 mu C ) |
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| 85 | In the definition of electric potential, the electric potential at infinity is assumed to be A . infinity B. zero c. 1 D. None of these |
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| 86 | Below, three different arrangement of identical capacitors are shown. What is the correct order of total capacitance values for the arrangements, greatest first? ( mathbf{A} cdot 1,2,3 ) в. 3,2,1 ( c cdot 3,1,2 ) D. 2,3,1 E .2,1,3 |
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| 87 | Consider the situation of figure. The work done in taking a point charge from ( P ) to ( A ) is ( W_{A}, ) from ( P ) to ( B ) is ( W_{B} ) and from ( P ) to ( C ) is ( W_{C} . ) Then : ( mathbf{A} cdot W_{A}<W_{B}W_{B}>W_{C} ) ( mathbf{c} cdot W_{A}=W_{B}=W_{C} ) D. None of these |
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| 88 | What is the electric potential at a distance of ( 9 mathrm{cm} ) from 3 nC? ( mathbf{A} cdot 270 V ) в. ( 3 V ) ( mathbf{c} .300 V ) D. 30V |
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| 89 | Find the equivalent capacitance of the arrangement of three capacitors shown in figure between points ( X ) and ( Y ) |
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| 90 | Consider a spherical shell of radius ( mathrm{R} ) with a total charge + q uniformly spread on its surface(center of the chell lies at the origin ( x=0 ) ). Two point charges, ( +q ) and ( -q ) are brought, one after the other, from far away and placed at ( x=-a / 2 ) and ( boldsymbol{x}=+boldsymbol{a} / 2(boldsymbol{a}<boldsymbol{R}), ) respectively Magnitude of the work done in this process is? A ( cdot(Q+q)^{2} cdot 4 pi varepsilon_{0} ) ( a ) B. Zero ( mathbf{c} cdot q^{2} / 4 pi varepsilon_{0} ) D ( cdot Q q / 4 pi varepsilon_{0} a ) |
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| 91 | Two charged spheres of radii ( boldsymbol{R}_{1} ) and ( boldsymbol{R}_{2} ) have equal surface charge density. The ratio of their potential at an equidistant external point is A ( cdot frac{R_{2}}{R_{1}} ) в. ( left(frac{R_{2}}{R_{1}}right)^{2} ) ( ^{mathbf{c}} cdotleft(frac{R_{1}}{R_{2}}right)^{2} ) D. ( frac{R_{1}}{R_{2}} ) |
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| 92 | The length of a conductor is halved. Its conductance will be? A. Halvedd B. Unchanged c. Doubled D. Quadrupled |
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| 93 | Four chargers ( q_{1}=-0.02 mu C, q_{2}= ) ( +0.04 mu C, q_{3}=+0.02 mu C, ) and ( q_{4}= ) ( -0.04 mu C ) are at the four corners of a square of side ( 9 mathrm{cm} ). Then the potential at the centre of the square is : A . ( 9 V ) в. ( 3 V ) ( mathrm{c} .1 .2 mathrm{V} ) D. Zero |
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| 94 | An electrical technician requires a capacitance of ( 2 mu F ) in a circuit across a potential difference of ( 1 mathrm{kV} . ) A large number of ( 1 mu F ) capacitors are available to him each of which can withstand a potential difference of not more than ( 400 mathrm{V} . ) Suggest a possible arrangement that requires the minimum number of capacitors. |
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| 95 | S.I. unit of electrical capacity. A. Stat Farad B. Farad c. Coulomb D. stat Coulomb |
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| 96 | Find ( V_{b a} ) if ( 12 J ) of work has to be done against an electric field to take a charge of ( 10^{-2} C ) from ( a ) to ( b ) A . ( 1000 V ) B. 1200V c. ( 1100 V ) D. 2400V |
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| 97 | which of the following is/are not proportional to the inverse square of the distance ( times ? ) This question has multiple correct options A. The potential at a distance ( x ) from an isolated point charge B. the electric field at a distance ( x ) from an isolated point charge C. The force per unit length between two thin, straight, infinitely long current carrying conductors, parallel to each other, separated by a distance ( x ) D. The gravitational attraction between two small bodies kept at a distance x apart |
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| 98 | 64 small drops of mercury each of radius ( r ) and change ( q ) coalesce to from a big drop. The ratio of the surface charge density of each small drop with that of big drop is: A . 4: 1 B. 1: 4 ( mathbf{c} cdot 1: 64 ) D. 64: 1 |
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| 99 | Calculate the electrostatic potential energy of an electron-proton system of hydrogen atom. In the first Bohr orbit of hydrogen atom, the radius of the orbit is ( 5.3 times 10^{-11} m ) A. ( -4.35 times 10^{-18} mathrm{J} ) В. ( -2.175 times 10^{-18} mathrm{J} ) c. ( -4.35 times 10^{-19} J ) D. ( -2.175 times 10^{-19} mathrm{J} ) |
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| 100 | A hollow spherical conductor of radius ( R ) is given a charge ( Q . ) Work done in moving a charge ( q ) from its centre to surface is : A ( cdot frac{Q q}{4 pi varepsilon_{0} R} ) в. ( frac{Q q}{2 pi varepsilon_{0} R} ) c. ( frac{Q q}{pi varepsilon_{0} R} ) D. zero |
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| 101 | The two plate ( X ) and ( Y ) of a parallel- plates capacitor of capacitance ( mathbf{C} ) are given a charge of amount Q each. ( X ) is now joined to the positive terminal and y to the negative terminal of a cell of emf ( varepsilon=Q / C ) This question has multiple correct options A. Charge of amount Q will flow from the positive terminal to the negative terminal of the cell through the capacitor. B. The total charge on the plate ( X ) will be ( 2 Q ) C. The total charge on the plate Y will be zero. D. The cell will supply ( C varepsilon^{2} ) amount of energy. |
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| 102 | A plane electromagnetic wave travelling in a non magnetic medium is given by ( boldsymbol{E}=left(boldsymbol{9} times mathbf{1 0}^{8} boldsymbol{N} boldsymbol{C}^{-1}right) boldsymbol{s i n}[(boldsymbol{9} times ) ( left.10^{8} text { rads}^{-1}right) t-left(6 m^{-1}right) x ) Where ( x ) is in metre and ( t ) is in second. The dielectric constant of the medium is: A. 5 B. 4 ( c cdot 3 ) D. |
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| 103 | A capacitor of capacity ( 10 mu F ) is charged to a potential of ( 10000 mathrm{V} ) and a wire is stretched by ( 0.2 m ) by a force of ( mathbf{5 0 0 0} N . ) The ration of the potential energies stored in them will be A . 1 в. 500 c. 0.002 D. 0.0001 |
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| 104 | Four identical metal plates are located in air at equal distance ( d ) from one another as shown in figure. The area of each plate is equal to ( A ). Find the capacitance of the system between points ( A ) and ( B ) |
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| 105 | In a circuit, ( 5 C ) of charge is passed through a battery in 3 hours. The plates of the battery are maintained at the potential difference of 12 V. Then, the amount of work done by a battery is: A . 60 J в. 180 c. 20 D. ( 6.48 times 10^{5} ) 」 |
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| 106 | A ( 10.0 mu F ) parallel-plate capacitor with circular plates is connected to a ( 12.0 mathrm{V} ) battery. How much charge ( (text { in } mu C) ) would be on the plates if their separation were doubled while the capacitor remained connected to the battery? |
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| 107 | Two identical thin rings each of radius ( r ) are coaxillary placed at a distance have equal charge q each. Work done in moving a charge ( q^{prime} ) from the centre of one ring to that of the other is? A . Infinity В. ( frac{q^{2}}{4 pi varepsilon_{0} r} ) c. zero D. ( frac{q q^{prime}}{4 pi varepsilon_{0} r} ) |
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| 108 | A parallel plate capacitor is charged. If the plates are pulled apart A. The capacitance increases B. The potential difference increases c. The total charge increases D. The charge and potential difference remain the same |
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| 109 | A parallel plate condenser with oil between the plates (dielectric constant of oil ( K=2 ) ) has a capacitance ( C . ) If the oil is removed, then capacitance of the capacitor becomes: A ( cdot sqrt{2} C ) B. 2C c. ( frac{c}{sqrt{2}} ) D. ( frac{c}{2} ) |
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| 110 | Two electric charges of ( 9 mu C ) and ( -3 mu C ) are placed ( 0.16 m ) apart in air. There will be a point ( mathrm{P} ) at which electric potential is ( z ) ero on the line joining the two charges and in between them. The distance of ( mathrm{P} ) from ( 9 mu C ) charge is: A ( .0 .14 m ) B. ( 0.12 m ) c. ( 0.08 m ) D. ( 0.06 m ) |
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| 111 | If one of the two electrons of a ( boldsymbol{H}_{2} ) molecule is removed, we get a hydrogen molecular ion ( boldsymbol{H}_{2}^{+} . ) In the ground state of an ( H_{2}^{+}, ) the two protons are separated by roughly ( 1.5 A ), and the electron is roughly ( 1 A ) from each proton. Determine the potential energy of the system. Specify your choice of the zero of potential energy. |
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| 112 | The work done (in Joule) in carrying a charge of 100 coulomb between two points having a potential difference of 10 volt is: A . ( 0 . ) B. 10 ( c cdot 100 ) D. 1000 |
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| 113 | An isolated parallel plate capacitor is charged upto a certain potential difference. When a ( 3 m m ) thick slab is introduced between the plates then in order to maintain the same potential difference, the distance between the plates is increased by ( 2.4 m m ). Find the dielectric constant of the slab. (Assume charge remains constant) A. 5 в. 10 ( c cdot 2.5 ) D. 7.5 |
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| 114 | At room temperature, if the relative permittivity of water be 80 and the relative permeability be 0.0222 , then the velocity of light in water is ( boldsymbol{m} / boldsymbol{s}^{-1} ) A . ( 3 times 10^{8} ) В. ( 2.25 times 10^{8} ) c. ( 2.5 times 10^{8} ) D. ( 3.5 times 10^{8} ) |
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| 115 | Two parallel plate capacitor of capacitances ( C ) and ( 2 C ) are connected in parallel and charged to a potential difference V. If the battery is disconnected and the space between the plate of the capacitor of capacince ( C ) is completely filled with a material of dielectric constant ( K, ) then the potential difference across the capacitor will be come A. ( 3 V(K+2) ) B. ( frac{(K+2)}{3 V} ) c. ( frac{3 V}{(K+2)} ) D. ( frac{3(K+2)}{V} ) |
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| 116 | A conductor A is given a charge of amount ( +Q ) and then placed inside a deep metal can B, without touching it. Then: This question has multiple correct options A. The potential of A does not change when it is place inside B. B. If ( B ) is earthed, ( +Q ) amount charge flows from it into the earth. C. If ( B ) is earthed, the potential of ( A ) is reduced D. Either (B) or (C) is true or both the true only if the outer surface of B is connected to earth and not its inner surface |
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| 117 | Charges ( 2 mu C ) and ( 1 mu C ) are placed at corners ( A ) and ( B ) of square of side ( 5 mathrm{cm} ) as shown in figure. The amount of work to be done against the electric field in moving a charge of ( 1.0 times 10^{-6} C ) from ( C ) to ( D ) is : B. 0.053 J c. ( 0.017 J ) begin{tabular}{l} .0 .035 \ hline end{tabular} |
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| 118 | A hollow metallic sphere of radius ( 10 mathrm{cm} ) is given a charge of ( 3.2 times 10^{-9} mathrm{C} ) The electric intensity at a point ( 4 mathrm{cm} ) from the centre is A ( cdot 9 times 10^{-9} N C^{-1} ) В. ( 288 N C^{-1} ) c. ( 2.88 N C^{-1} ) D. zero |
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| 119 | A uniform charged solid sphere of radius ( R ) has potential ( V_{0} ) (measure with respect to ( infty ) ) on its surface. For this sphere the equipotential surfaces with potentials ( frac{3 V_{0}}{2}, frac{5 V_{0}}{4}, frac{3 V_{0}}{4}, frac{V_{0}}{4} ) have radius ( R_{1}, R_{2}, R_{3} ) and ( R_{4} ) respectively. Then A. ( R_{1}=0 ) and ( R_{2}>left(R_{4} R_{3}right) ) B. ( R_{1} neq 0 ) and ( left(R_{2} R_{1}right)>left(R_{4} R_{3}right) ) c. ( R_{1}=0 ) and ( R_{2}<left(R_{4} R_{3}right) ) D . ( 2 R<R_{4} ) |
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| 120 | Find equivalent capacitance between points ( A ) and ( B: ) Essume each conducting plate is having same dimensions and neglect the thickness of the plate, ( frac{varepsilon_{0} A}{d}=7 mu F ) where A is area of plates ( mathbf{A} cdot 7 mu F ) B. ( 11 mu F ) ( mathbf{c} cdot 12 mu F ) D. ( 15 mu F ) |
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| 121 | Assertion Charge on all the condensers connected in series is the same. Reason Charge present on a capacitor is directly proportional to its capacitance A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 122 | Potential at the point of a pointed conductor is greater than the other points on surface: A. True B. False |
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| 123 | The work done in moving a single positive charge from infinity to a point is called ( ldots . . ) at that point A. Electricity B. Electric potential c. Potential gradient D. None of these |
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| 124 | topp Q type your question difference across the plates with respect to the charge on the condenser? ( A ) B. ( c ) ( D ) |
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| 125 | Consider a huge charge reservoir at potential ( V=200 ) volts. A spherical capacitor ( C_{1}=40 n F ) is brought in contact with the charge reservoir and then removed. Afterwards, another spherical capacitor ( C_{2}=30 n F ) is brought in contact with ( C_{1} ) and removed. This process is repeated many times. Assume that potential of reservoir does not change during this exercise. Then the charge in ( (mu C) ) on ( C_{2} ) after a very long time is : A . 6 B. 3 ( c .9 ) D. 12 |
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| 126 | The figure shows a circuit consisting of four capacitors. Find the effective capacitance between ( boldsymbol{X} ) and ( boldsymbol{Y} ) |
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| 127 | A solid conducting sphere having a charge ( Q ) is surrounded by an uncharged concentric conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be ( V ). If the shell is now given a charge ( -3 Q ), the new potential difference between the same two surfaces is: ( mathbf{A} cdot V ) B. ( 2 V ) c. ( 4 V ) ( mathbf{D} cdot-2 V ) |
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| 128 | In the following network, potential at 0 is ( 4.4 v ) ( 3.3 v ) ( c cdot 6 v ) ( D cdot 4.8 v ) |
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| 129 | A capacitor consists of two metal plates each ( 10 mathrm{cm} ) by ( 20 mathrm{cm} ; ) they are separated by a 2.0 mm thick insulator with dielectric constant 4.1 and dielectric strength ( 6.0107 mathrm{V} / mathrm{m} . ) What is the capacitance in ( boldsymbol{p} boldsymbol{F}left(mathbf{1 0}^{-12} boldsymbol{F}right) ? ) A . 75 B. 100 ( c cdot 240 ) D. 360 |
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| 130 | Q Type your question Nư. between the plates. The battery is then disconnected and a dielectric slab of dielectric constant ( K ) is placed in between the plates of the capacitor as shown. Now, answer the following questions based on above information. The |
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| 131 | If the dielectric constant and dielectric strength be denoted by ( K ) and ( X ) respectively, then a material, suitable for use as a dielectric in a capacitors, must have : A. high ( K ) and high ( X ) B. high ( K ) and low ( X ) c. low ( K ) and high ( X ) D. low ( K ) and low ( X ) |
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| 132 | Two charges ( q_{1} ) and ( q_{2} ) are placed ( 30 c m ) a part as shown. A third charge ( q_{3} ) is moved along the circle of radius ( 40 mathrm{cm} ) from ( C ) to ( D ). The change in the potential energy of the system is ( frac{q_{3} K}{4 pi epsilon_{0}} ) Find K? ( mathbf{A} cdot 8 q_{2} ) B. ( 8 q ) ( c cdot 6 q_{2} ) D. ( 6 q ) |
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| 133 | Consider a point charge with ( boldsymbol{q}=mathbf{1 . 5} times ) ( 10^{-8} C . ) Then, the radius of an equipotential surface having a potential of ( 30 V ) is : A ( .0 .45 m ) в. 4.5 т c. infinite D. none of the above |
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| 134 | is said to be done when an electric charge flows through a conductor at some potential difference. |
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| 135 | The diagram shows equipotential lines from an unknown charge configuration. Determine where in the diagram the field is closest to uniform: ( A cdot A ) B. B ( c cdot c ) ( D ) |
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| 136 | A ( 10.0 mu F ) parallel-plate capacitor with circular plates is connected to a ( 12.0 mathrm{V} ) battery. What is the charge on each plate ( (operatorname{in} mu C) ? ) |
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| 137 | Match the following two columns: ( begin{array}{llll} & text { Column I } & & text { Column II } \ text { A. } & begin{array}{l}text { Electrical } \ text { resistance }end{array} & 1 . & {left[M L^{3} T^{-3} A^{-2}right]} \ text {B. } & begin{array}{l}text { Electrical } \ text { potential }end{array} & 2 . & {left[M L^{2} T^{-3} A^{-2}right]} \ text {C. } & begin{array}{l}text { Specific } \ text { resistance }end{array} & 3 . & {left[M L^{2} T^{-3} A^{-1}right]} \ text {D. } & begin{array}{l}text { Specific } \ text { conductance }end{array} & 4 . & text { None of these }end{array} ) ( mathbf{A} cdot A-2, B-3, C-1, D-4 ) ( mathbf{B} cdot A-2, B-4, C-3, D-1 ) c. ( A-1, B-2, C-3, D-3 ) D. ( A-1, B-3, C-2, D-4 ) |
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| 138 | State whether given statement is True or False
The dielectric constant is the ability of a material to establish an electric field. |
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| 139 | A charge of ( 20 mu C ) produces an electric field. Two points are ( 10 mathrm{cm} ) and ( 5 mathrm{cm} ) away from this charge. Find the values of potentials at these points and also find the amount of work done to take an electron from one point to the other |
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| 140 | Given four capacitors each of capacity ( 12 mu ) F. To get a capacity of ( 9 mu mathrm{F} ), what combination can be used: A. All in series B. All in parallel c. 3 in parallel and 1 series with them D. 2 in parallel and 2 in series |
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| 141 | Some charge is being given to a conductor. Then its potential: A. is maximum somewhere between surface and centre. B. is maximum at surface. C. is maximum at centre. D. remains same throughout the conductor |
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| 142 | Two particles ( X ) and ( Y ) having equal charges after being accelerated thorough the same potential difference enter a region of uniform magnetic field and describe circular paths of radius ( boldsymbol{R}_{1} ) and ( boldsymbol{R}_{2} ) respectively. the ratio of mass of ( X ) to that of ( Y ) is ( mathbf{A} cdot sqrt{R_{1} / R_{2}} ) в. ( R_{2} / R_{1} ) c. ( left(R_{1} / R_{2}right)^{2} ) D. ( R_{1} / R_{2} ) |
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| 143 | Identify the correct statement from below: ( mathbf{A} cdot ) A will be at higher potential B. B will be at higher potential C. Both will be at same potential D. Can’t be said |
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| 144 | Two identical capacitors are connected in series with a source of potential V. If ( mathrm{Q} ) is the charge on one of the capacitors, the capacitance of each capacitor is: A ( cdot ) Q/2 B. 2Q/V c. ( mathrm{Q} / mathrm{v} ) D. None of these |
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| 145 | A parallel plate air has a capacity of ( 20 mu F ). what will be the new capacity if a marble slab of dielectric constant 8 is introduced between the two plates? |
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| 146 | Three capacitors ( 2 mu F, 3 mu F ) and ( 6 mu F ) are connected in series. The effective capacitance of the combination is: ( mathbf{A} cdot 11 mu F ) в. ( 1 mu F ) c. ( 1.2 mu F ) D. ( 2 mu F ) |
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| 147 | A parallel plate capacitor is charged and then disconnected from the charging battery. If the plates are now moved farther apart by pulling at them by means of insulating handles, then: A. the energy stored in the capacitor decreases B. the capacitance of the capacitor increases c. the charge on the capacitor decreases D. the voltage across the capacitor increases |
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| 148 | The potential energy of the system of two identically charged spheres as shown in the figure is equal to (Assume the charge distribution to be uniform) ( ^{mathbf{A}} cdot frac{q^{2}}{4 pi varepsilon_{0}}left[frac{1}{R}+frac{1}{r}right] ) в. ( frac{1}{4 pi varepsilon_{0}} frac{q^{2}}{r} ) c. ( frac{1}{4 pi varepsilon_{0}} frac{q^{2}}{(R+r)} ) D. None of these |
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| 149 | What is dielectric substance? | 12 |
| 150 | Dielectric constant of a metal is A. zero B. Infinite c. Finite D. Unpredictable |
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| 151 | A parallel plate capacitors is formed by stacking n equally spaced plates connected alternately. If capacitance between two adjacent plates is ( C ) then the resultant capacitance is : A. ( (n-1) C ) в. ( (n+1) C ) ( c . c ) D. ( n C ) |
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| 152 | Two ( C u^{64} ) nuclei touch each other. The electrostatics repulsive energy of the system will be A. 0.788 MeV в. 7.88 Ме ( V ) c. 126.15 MeV D. 788 MeV |
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| 153 | A charge of ( 1 mu C ) is given to one plate of a capacitors and a charge of ( 2 mu mathrm{C} ) is given to the other plate of a ( 0.1 mu mathrm{F} ) capacitor. Find the potential difference across the two plates of the capacitor: ( mathbf{A} cdot 5 V ) в. ( 10 V ) ( mathrm{c} cdot 15 mathrm{V} ) D. 30 ( V ) |
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| 154 | The radius of two metallic sphere ( A ) and ( B ) are ( r_{1} ) and ( r_{2} ) respectively ( left(r_{1}>r_{2}right) ) They are connected by a thin wire and the system is given a certain charge. The charge will be greater A. Equal to both B. Zero on both c. on the surface of sphere ( A ) D. On the surface of sphere ( B ) |
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| 155 | A parallel plate air capacitor has capacity’ ( C^{prime}, ) distance of separation between plate is ‘ ( d^{prime} ) and potential difference ( ^{prime} V^{prime} ) is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is: ( ^{mathbf{A}} cdot frac{C^{2} V^{2}}{2 d^{2}} ) B. ( frac{C^{2} V^{2}}{2 d} ) ( c cdot frac{C V^{2}}{2 d} ) D. ( frac{C^{2} V}{d} ) |
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| 156 | In the electric field of an point charge ( q ) a certain charge is carried from point ( mathbf{A} ) to ( mathrm{B}, mathrm{C}, mathrm{D} ) and ( mathrm{E} ). Then the work done during movement along each path is: A. least along the path AB B. least along the path AD C. zero along any one of the path ( A B, A C, A D ) and ( A E ) D. least along AE |
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| 157 | The work done by electric field in carrying a point charge of ( 5 mu C ) from a point ( A ) to point ( B ) is 10 mJ. The potential difference ( boldsymbol{V}_{boldsymbol{A}}-boldsymbol{V}_{boldsymbol{B}} ) is the: ( A cdot+2 k V ) B. -2 kV ( c cdot+2000 v ) D. -2000V |
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| 158 | Equipotential surfaces are A. Surfaces that are perpendicular to gravitational fields B. Surfaces that have same mass on top of it c. surface that have same radius of curvature D. Surfaces that have same gravitational field on it |
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| 159 | The plates of a parallel plate capacitor are charged with surface densities ( sigma_{1} ) and ( sigma_{2}left(sigma_{1}=sigma text { and } sigma_{2}=-sigmaright) ) respectively and placed horizontally. The electric field at points : This question has multiple correct options A. inside the region between the plates will be zeroro B. above the upper plate and below the lower plate will be zero c. everywhere in space will be zero D. inside the region between the plates will be uniform and non zero (neglecting other effects) |
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| 160 | Charges ( 1 mu C ) are placed at each of the four corners of a square of side ( 2 sqrt{2} m ) The potential at the point of intersection of the diagonals is ( _{-}-_{-}-_{-}(K=9 times ) ( left.mathbf{1 0}^{mathbf{9}} boldsymbol{S} boldsymbol{I} text { unit }right) ) ( mathbf{A} cdot 18 times 10^{3} V ) в. ( 1800 mathrm{V} ) ( mathbf{c} cdot 18 sqrt{2} times 10^{3} V ) D. None of these |
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| 161 | If the charge on a capacitor is increased by 2 colomb, the energy stored in it increases by ( 21 % ). The original charge on the capacitor is A . 10 B. 20 c. 30 D. 40 |
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| 162 | A uniformly charged solid sphere or radius ( boldsymbol{R} ) has potential ( boldsymbol{V}_{mathbf{0}} ) (measured with respect to ( infty ) ) on its surface. For this sphere the equipotential surfaces with potentials ( frac{3 V_{0}}{2}, frac{5 V_{0}}{4}, frac{3 V_{0}}{4}, frac{V_{0}}{4} ) have radius ( boldsymbol{R}_{1}, boldsymbol{R}_{2}, boldsymbol{R}_{3} ) and ( boldsymbol{R}_{4} ) respectively. Then A ( cdot R_{1}=0 ) and ( R_{2}left(R_{4}-R_{3}right) ) B . ( R_{1} neq 0 ) and ( left(R_{1}-R_{1}right)>left(R_{4}-R_{3}right) ) c. ( R_{1}=0 ) and ( R_{2}>left(R_{4}-R_{3}right) ) D. none of these |
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| 163 | sheets having charges ( Q ) and ( 2 Q ) are placed parallel to each other as shown in Fig. The charge distribution on the four faces of the two plates is also shown. The electric field intensities at three points ( 1,2, ) and 3 are ( vec{E}_{1}, vec{E}_{2}, ) and ( vec{E}_{3}, ) respectively. Then the magnitudes of ( overrightarrow{boldsymbol{E}}_{1}, overrightarrow{boldsymbol{E}}_{3} ) and ( overrightarrow{boldsymbol{E}}_{2} ) are respectively (surface area of plates): ( A ) ( 0, frac{Q}{varepsilon_{0} S}, 0 ) B. ( frac{5 Q}{6 varepsilon_{0} S}, frac{Q}{2 varepsilon_{0} S}, 0 ) c. ( frac{5 Q}{6 varepsilon_{0} S}, frac{Q}{varepsilon_{0} S}, frac{Q}{3 varepsilon_{0} S} ) D. ( 0, frac{Q}{2 varepsilon_{0} S}, 0 ) |
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| 164 | Calculate the area of the plates of a one farad parallel plate capacitor if separation between plates is ( 1 mathrm{mm} ) and plates are in vacuum: A ( cdot 18 times 10^{8} m^{2} ) B . ( 0.3 times 10^{8} m^{2} ) c. ( 1.3 times 10^{8} m^{2} ) D. ( 1.13 times 10^{8} m^{2} ) |
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| 165 | A pendulum with a bob hanging is suspended such that the electric field is in upward direction. At equilibrium of the bob, the change in tension in the string will be (assuming rest condition) A . ( m g ) в. ( q E ) ( c cdot 2 q E ) D. ( q E / 2 ) |
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| 166 | In an isolated parallel plate capacitor of capacitance ( C, ) the four surfaces have charges ( Q_{1}, Q_{2}, Q_{3} ) and ( Q_{4} ) as shown. The potential difference between the plates is: ( A ) в. ( frac{Q_{2}+Q_{3}}{2 C} ) c. ( frac{Q_{2}-Q_{3}}{2 C} ) D. ( frac{Q_{1}+Q_{4}}{2 C} ) |
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| 167 | In the arrangement of capacitors shown in Figure, if each capacitor is ( 9 mathrm{pF} ), the effective capacitance between ( A ) and ( B ) is A . ( 10 p ) В. 15 p ( c .20 p F ) D. ( 5 p F ) |
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| 168 | The effective capacitance between the point ( P ) and ( Q ) of the arrangement shown in the figure is: |
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| 169 | A child stands inside a large charged metal sphere. Will her hair stand on end? A. Yes B. No c. Incomplete information D. No guess about her hair style |
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| 170 | A condenser of capacity ( C ) is charged to a potential difference of ( V_{1} . ) The plates of the condenser are then connected to an ideal inductor of inductance ( L ). The current through the inductor when the potential difference across the condenser reduces to ( V_{2} ) is ( left(frac{Cleft(V_{1}-V_{2}right)^{2}}{L}right)^{frac{1}{2}} ) в. ( frac{Cleft(V_{1}^{2}-V_{2}^{2}right)}{L} ) c. ( frac{Cleft(V_{1}^{2}+V_{2}^{2}right)}{L} ) ( left(frac{Cleft(V_{1}^{2}-V_{2}^{2}right)}{L}right)^{frac{1}{2}} ) |
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| 171 | The plates of a parallel plate capacitor are charged upto ( 100 V . ) now, after removing the battery, a ( 2 m m ) thick plate is inserted between the plates. Then, to maintain the same potential difference, the distance between the capacitor plates is increased by ( 1.6 m m ) The dielectric constant of the plate is : A . 5 B. 1.25 ( c cdot 4 ) D. 2.5 |
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| 172 | An uncharged metal object ( M ) is insultated from its surroundings.A positively charges metal sphere ( boldsymbol{S} ) is then brought near to ( M . ) Which diagram illustrate the resultant distribution of charge on ( S ) and ( M ) ( A ) в. ( c ) D. |
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| 173 | A parallel plate capacitor, at a capacity ( 100 mu F ), is charged by a battery at ( 50 mathrm{V} ) The battery remains connected and if the plates of the capacitor are separated so that the distance between them is reduced to half of the original distance, the additional energy given by the battery to the capacitor in ( J ) is: A ( cdot 125 times 10^{-3} ) В. ( 12.5 times 10^{-3} ) с. ( 1.25 times 10^{-3} ) . D. ( 0.125 times 10^{-3} ) |
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| 174 | Identify the true expression: A ( cdot V=J C^{-1} ) B. ( V=J C ) ( mathbf{c} cdot V=J C^{-2} ) D. ( V=J C^{-3} ) |
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| 175 | A particle having mass 1 g and electric charge ( 10^{-8} mathrm{C} ) travels from a point ( mathrm{A} ) having electric potential ( 600 mathrm{V} ) to the point B having zero potential. What would be the change in its kinetic energy? A . ( -6 times 10^{-6} ) erg В. ( -6 times 10^{-6} ) j c. ( 6 times 10^{-6} ) j D. ( 6 times 10^{-6} ) erg |
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| 176 | Find equivalent capacitance between points ( A ) and ( B ) : ( ^{A} cdot frac{5 C}{3} ) в. ( frac{4 C}{3} ) ( c . C ) 0.20 |
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| 177 | ( P, Q ) and ( R ) are three points in a uniform electric field. The electric potential is A. minimum at R B. minimum at ( c . ) minimum at D. Same at all three points |
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| 178 | Two point charges ( 10^{-5} mathrm{C} ) and ( -10^{-5} mathrm{C} ) are released from large separation. Their masses are 100 gm and 200 gm. If velocity of approach (in ( mathrm{m} / mathrm{s} ) ) of them when they are separated by distance ( 3 m ) is ( frac{x}{4} m / s . ) Then ( x ) is : A . 12 B. 1 ( c cdot 4 ) D. 8 |
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| 179 | The electric potential at point ( X ) is 20 V and at point Y is – 40 V. Then, the work done by an external force in moving an electron from ( X ) to ( Y ) is: ( mathbf{A} cdot 13 times 10^{-8} J ) В. ( 9.6 times 10^{-18} mathrm{J} ) c. ( 3.2 times 10^{-8} J ) D. ( 30 times 10^{-15} mathrm{J} ) |
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| 180 | Draw a neat labelled diagram of a parallel plate capacitor completely filled with dielectric. | 12 |
| 181 | Equipotentials at a great distance from a collection of charges whose total sum is not zero are approximately: A. spheres B. planes c. paraboloids D. ellipsoids. |
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| 182 | Five identical parallel conducting plates each of area A have separation ‘d between successive surface. The plates are connected to the terminal of a battery as shown in the figure. The effective capacitance of the circuit is A ( cdot frac{A varepsilon_{0}}{4 d} ) в. ( frac{4 A varepsilon_{0}}{d} ) c. ( frac{A varepsilon_{0}}{3 d} ) D. ( frac{3 A varepsilon_{0}}{4 d} ) |
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| 183 | Three charges ( +1 mu C,+3 mu C ) and ( -5 mu C ) are kept at the vertices of an equilateral triangle of sides ( 60 mathrm{cm} ). Find the electrostatic potential energy of the system of charges. |
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| 184 | Two similar parallel plate capacitors each of capacity ( C_{o} ) are connected in series, The combination is connected with a voltage source of ( V_{o} . ) Now separation between the plates of one capacitor is increased by a distance ( boldsymbol{d} ) and the separation between the plates of another capacitor is decreased by the distance ( d / 2 ) The distance between the plates of each capacitor was ( boldsymbol{d} ) before the change in separation. Then, select the correct choice : A. the new capacity of the system will increase B. the new capacity of the system will decrease c. the new capacity of the system will remain same D. data insufficient |
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| 185 | Derive an expression for the capacitance of a parallel plate capacitor. Why does the capacitance increase by using dielectric in capacitor? |
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| 186 | The associated figure shows an electric charge ( +q ) located at the centre of a hollow uncharged conducting metal sphere. Outside the sphere is a second charge ( +Q . ) Both charges are positive. Choose the description below that describes the net electrical forces on each charge in this situation. A. Both charges experience the same net force directed B. No net force experienced by either charge. c. There is no net force on Q but a net force on q D. There is no net force on q but a net force on ( Q ) E. Both charges experience a net force but they are diff |
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| 187 | There are n identical capacitors, which are connected in parallel to a potential difference ( V . ) These capacitors are then reconnected, in series. The potential difference between the extreme ends is: A . zero в. ( n V ) c. ( (n-1) V ) D. none of the above |
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| 188 | State whether the given statement is True or False: Six negative point charges are arranged symmetrically around a circle centered at point ( P ) as shown in the diagram below. All points charges are of the same magnitude Electric Field at ( mathrm{P} ) will be zero while electric potential at point ( P ) will be non zero. A. True B. False |
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| 189 | Column ( I ) has some statements about the system shown in column ( I I, ) Match appropriate column. |
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| 190 | Two thick plates having same charges (same charge density ( sigma ) ) are placed side by side. Consider the case of infinite plate. Find the difference between the electric field present between the plate and remaining space of the plate, ( (varepsilon=text { permittivity }) ) A ( cdot frac{sigma}{varepsilon} ) в. ( 2 frac{sigma}{varepsilon} ) c. ( frac{sigma}{2 varepsilon} ) D. |
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| 191 | Two thin wire rings each having a radius ( R ) are placed at a distance d apart with their axes coinciding. The charges on the two rings are ( +q ) and ( -q ) The potential difference between the centres of the two rings is A ( cdot frac{Q cdot R}{4 pi varepsilon d^{2}} ) B ( cdot frac{Q}{2 pi varepsilon_{0}}left[frac{1}{R}-frac{1}{sqrt{R^{2}+d^{2}}}right] ) c. ( frac{Q}{4 pi varepsilon_{0}}left[frac{1}{R}-frac{1}{sqrt{R^{2}+bar{d}^{2}}}right] ) D. |
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| 192 | A unit charge moves on an equipotential surface from a point ( A ) to point ( mathrm{B} ), then : A. ( V_{A}-V_{B}=+v e ) в. ( V_{A}-V_{B}=0 ) ( mathbf{c} cdot V_{A}-V_{B}=-v e ) D. it is stationary |
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| 193 | Two small identical metal balls ( A ) and ( B ) radius r are placed apart The distance between centre of balls is ( a_{0} ) The net potential of ball ( A ) is ( V_{1} ) and that of ( B ) is ( V_{2} ) Let ( q_{1} ) and ( q_{2} ) are the charges on balls A and B respectively Then the charge on ( A ) and ( B ) are ( left(left(g i v e n r<<a_{0}right)right) ) This question has multiple correct options A ( cdot q_{1}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}-V_{2} rright)}{a_{0}^{2}-r^{2}} ) В. ( quad q_{1}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}+V_{2} rright)}{a_{0}^{2}+r^{2}} ) ( ^{mathbf{C}} cdot_{q_{2}}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{2} a_{0}+V_{1} rright)}{a_{0}^{2}+r^{2}} ) D. ( _{q_{2}}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{2} a_{0}-V_{1} rright)}{a_{0}^{2}-r^{2}} ) |
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| 194 | A parallel plate air capacitor has a capacitance of ( 5 mu F . ) It becomes ( 50 mu F ) when a dielectric medium occupies the entire space between its two plates. What is the dielectric constant of the medium? |
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| 195 | The breakdown field strength for dry air is ( 3 times 10^{6} mathrm{V} / mathrm{m} ). Each of the plates of the parallel plate capacitor has an area of ( 0.2 m^{2} . ) The maximum charge that can be collected is : (Given permittivity of air ( left.epsilon_{circ}=8.85 times 10^{-12} C^{2} / N m^{2}right) ) A. ( 5.3 mu ) С в. ( 0.6 mu mathrm{c} ) c. ( 1.5 mu ) С D. ( 4.56 mu ) С |
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| 196 | Q Type your question Who did at the four corners of a square with sides of length D. What is the electric potential at the |
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| 197 | If charge on left plate of the ( 5 mu F ) capacitor in the circuit segment shown in the figure is ( -20 mu C ), the charge on the right plate of ( 3 mu F ) capacitor is : ( mathbf{A} cdot+8.57 mu C ) B. ( -8.57 mu C ) c. ( +11.42 mu C ) D. ( -11.42 mu C ) |
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| 198 | A parallel plate capacitor with air between the plates has a capacitance of ( 8 p Fleft(1 p F=10^{-12} Fright) . ) What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant ( 6 ? ) |
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| 199 | For capacitors in the series combination, the total capacitance ( C ) is given by ( ^{mathbf{A}} cdot_{C}=left(frac{1}{C_{1}}+frac{1}{C_{2}}+ldots ldotsright) ) в. ( C=C_{1}+C_{2}+ldots ) ( ^{mathbf{c}} cdot frac{1}{bar{C}}=left(frac{1}{C_{1}}+frac{1}{C_{2}}+ldots . .right) ) ( stackrel{mathrm{D}}{mathrm{C}}=C_{1}+C_{2}+ldots ) |
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| 200 | a conducting sphere ( A ) of radius a, with charge ( Q, ) is placed concentrically inside a conducting shell ( B ) of radius ( b ) B is earthed. ( C ) is the common centre of A and B: This question has multiple correct options A ( cdot ) The field at a distance r from ( mathrm{C} ), where ( a leq r leq b ), is ( k frac{Q}{r^{2}} ) B. The potential at a distance r from C, where ( a leq r leq b ), is ( k frac{Q}{r} ) C. The potential difference between A and B is, ( k Qleft(frac{1}{a}-frac{1}{b}right) ) D. The potential difference between r and C, where ( a leq ) ( r leq b, ) is ( k Qleft(frac{1}{a}-frac{1}{b}right) ) |
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| 201 | The potential difference between two parallel plates ( 1 mathrm{cm} ) apart is ( 100 mathrm{V} ). The electric field strength between them is : A. ( 100 V / m ) в. ( 1000 V / m ) c. ( 10^{4} V / m ) D. ( 50 V / m ) |
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| 202 | A network of four capacitors of capacity equal to ( C_{1}=C, C_{2}=2 C, C_{3}=3 C ) and ( C_{4}=4 C ) are connected to a battery as shown in the figure. The ratio of the charges on ( C_{2} ) and ( C_{4} ) is: |
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| 203 | topp Q Type your question spherical shell with inner radius ( c ) and outer radius ( d ) (as shown in Fig). The inner shell has total charge ( +2 q ) and the outer shell has charge ( +4 q ). Calculate the electric field in terms of ( q ) and the distance ( r ) from the common centre of the two shells for: ( a<r<b ) A. zero в. ( frac{1}{4 pi varepsilon_{8}} frac{2 q}{r^{2}} ) C. ( -frac{1}{4 pi varepsilon_{0}} frac{6 q}{r^{2}} ) D. ( frac{1}{4 pi varepsilon_{0}} frac{q}{r^{2}} ) |
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| 204 | Assertion Each of the plates of a parallel-plate capacitor is given equal positive charge Q. The charges on the facing surfaces will be same. Reason A negative charge (-Q) will be induced on each of the facing surfaces. A. If both Assertion and Reason are correct and Reason the correct explanation of Assertion B. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion c. If Assertion is correct but Reason is incorrect D. If Assertion is incorrect but Reason is correct |
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| 205 | Why must electrostatic field be normal to the surface at every point of a charged conductor? |
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| 206 | A fourth charge with charge ( +3 q ) is slowly moved in from infinity to point ( boldsymbol{P} ) How much work must be done in this process? ( A ) в. ( frac{3 q^{2}}{2 pi epsilon_{0} a} ) c. ( frac{3 q^{2}}{sqrt{3} pi epsilon_{0} a} ) D. ( frac{3 q^{2}}{4 pi epsilon_{n}} ) |
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| 207 | Two metallic plates are kept parallel to one another and charges are given to them as shown in figure. Find the charge on all the four faces |
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| 208 | Derive an expression for the energy stored per unit volume (energy density) in an electric field. OR Obtain an expression for energy density of a medium. |
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| 209 | The potential at a point due to a charge of ( 5 times 10^{-7} C ) located ( 10 c m ) away is ( 4.5 times 10^{4} V . ) The work done in bringing a charge of ( 4 times 10^{-9} C ) from infinity to that point is: A ( .2 .4 times 10^{-4} J ) В. ( 1.8 times 10^{-4} mathrm{J} ) c. ( 3.2 times 10^{-5} J ) D. ( 4.1 times 10^{-5} J ) |
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| 210 | The potential of a large liquid drop when eight liquid drops are combined is ( 20 V ) Then the potential of each single drop was: A . ( 10 V ) в. ( 7.5 V ) ( c .5 V ) D. 2.5V |
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| 211 | The energy density in a parallel plate capacitor is given as ( 1.8 times 10^{-9} J / m^{3} ) The value of the electric field in the region between the plates is : ( left(epsilon_{0}=9 times 10^{-12}right) ) ( mathbf{A} cdot 6.6 N C^{-1} ) B. ( 20 N C^{-1} ) ( mathbf{c} cdot 66 N C^{-1} ) D. ( 2 N C^{-1} ) |
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| 212 | A1 ( mu F ) capacitor and a ( 2 mu F ) capacitor are connected in series across a ( 1200 mathrm{V} ) supply line. The charged capacitors are disconnected from the line and from each other and reconnected with terminals of like sign together. Find the final charge on each and the voltage across them: A ( cdot frac{1600}{13} V ) В. ( frac{1600}{32} V ) c. ( frac{1600}{3} V ) D. ( frac{160}{3} V ) |
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| 213 | A condenser of capacity ( 2 mu F ) is charged to a potential of ( 200 mathrm{V} ). It is now connected to an uncharged condenser of capacity ( 3 mu F ). The common potential is : A . 200 B. ( 100 mathrm{V} ) c. ( 80 v ) D. 40 |
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| 214 | Two conducting plates ( A ) and ( B ) are parallel. A is given a charge ( Q_{1} ) and ( B ) is given a charge ( Q_{2} ). The charge on inner side of B is : ( A ) [ frac{Q_{2}-Q_{1}}{2} ] в. [ frac{left(Q_{1}-Q_{2}right)}{2} ] ( c ) [ frac{left(Q_{1}+Q_{2}right)}{2} ] ( D ) [ frac{-left(Q_{1}+Q_{2}right)}{2} ] |
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| 215 | The charge appearing on the outer surface of extreme left plate is : A . ( -(Q / 2) ) B. ( (Q / 2) ) ( c cdot Q ) D. – |
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| 216 | A hollow metal sphere of radius ( 5 mathrm{cm} ) is charged such that the potential on its surface is 10 volts. The potential at the centre of the sphere will be: A . zero B. 5 volts c. 10 volts D. 0.2 volts |
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| 217 | What is the S.I. unit of electric potential? A. ampere B. volt c. volt.m D. coulomb |
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| 218 | Two electric charges of ( 9 mu C ) and ( -3 mu C ) are placed ( 0.16 mathrm{m} ) apart in air. There are two points ( A ) and ( B ) on the line joining the two charges at distances of (i) ( 0.04 m ) from ( -3 mu C ) and in between the charges and (ii) ( 0.08 m ) from ( -3 mu C ) and out side the two charges. The potentials at ( A ) and B are : A. ( 0 V, 5 V ) в. ( 0 V, 0 V ) c. ( 5 V, 0 V ) D. ( 5 V, 10 V ) |
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| 219 | plates ( A, B ) and ( C ) are placed as shown. Switches ( S_{1} ) and ( S_{2} ) are open, and can connect ( A ) and ( C ) to earth when closed. ( +Q ) charge is given to ( B: ) This question has multiple correct options A. If ( S_{1} ) is closed with ( S_{2} ) open, a charge of amount ( Q ) will pass through ( S_{1} ) B. If ( S_{2} ) is closed with ( S_{1} ) open, a charge of amount ( Q ) will pass through ( S_{2} ) c. If ( S_{1} ) and ( S_{2} ) are closed together, a charge of amount Q/3 will pass through ( S_{1} ), and a charge of amount ( 2 Q / 3 ) will pass through ( S_{2} ) D. All the above statements are incorrect |
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| 220 | A parallel plate condenser has plates of area ( 200 mathrm{cm}^{2} ) and separation ( 0.05 mathrm{cm} ) The space between plates have been filled with a dielectric having ( mathbf{k}=mathbf{8} ) and then charged to 300 volts. The stored energy: A . ( 121.5 times 10^{-6} mathrm{J} ) В. ( 28 times 10^{-6} mathrm{J} ) D. ( 1.6 times 64 times 10^{-5} mathrm{J} ) |
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| 221 | Show that the force on each plate of a parallel plate capacitor has a magnitude equal to ( left(frac{1}{2}right) mathrm{QE} ), where ( mathrm{Q} ) is the charge on the capacitor, and E is the magnitude of electric field between the plates. Explain the origin of the factor. |
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| 222 | The relative permittivity of water is ( 81 . ) If ( varepsilon_{0} ) and ( varepsilon ) are permittivities of vaccum and water respectively Then: A ( cdot varepsilon_{0}=9 varepsilon_{w} ) В. ( varepsilon_{0}=81 varepsilon_{w} ) ( mathbf{c} cdot varepsilon_{w}=9 varepsilon_{0} ) D. ( varepsilon_{w}=81 varepsilon_{0} ) |
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| 223 | Two parallel wires are suspended in vacuum. When the potential difference between the wires is 30 V then the charge on the wires is ( 140 mu C ). The capacitance of the system of wires will be: A ( .4 .66 mu F ) в. ( 5 mu F ) c. ( 10.21 mu F ) ( mathbf{D} cdot 50 mu F ) |
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| 224 | A non conducting rod ( A B ) of length ( sqrt{3} R ) uniformly distributed charge of linear charge density ( lambda ) and.a non-conducting ring of uniformly distributed charge ( Q ) are placed as shown in the figure. Point A is the centre of ring and line ( A B ) is the axis of the ring, perpendicular to plane of ring. The electrostatic interaction energy between ring and rod is A ( cdot frac{Q lambda}{4 pi epsilon_{l}} ln (2+sqrt{3}) ) c. ( frac{Q lambda}{4 pi epsilon} ln (2-sqrt{3}) ) D・frac{Qlambda } ( {2 pi epsilon} ln (2-sqrt{3}) ) |
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| 225 | Two charges are at a distance ( d ) apart. If ( boldsymbol{d} ) a copper plate of thickness ( frac{u}{2} ) is kept between them, the effective force will be A. ( F / 2 ) B. zero ( c cdot 2 F ) D. ( sqrt{2} F ) |
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| 226 | Complete the following statements with an appropriate word /term be filled in the blank space(s). The equivalent capacitance ( C ) for the series combination of three |
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| 227 | toppr Q Type your question an electric field that decreases with altitude. Near the surface of the earth, the field is about ( 100 V m^{-1} . ) Why then do we not get an electric shock as we step out of our house into the open? (Assume the house to be a steel cage so there is no field inside!) (b) A man fixes outside his house one evening a two metre high insulating slab carrying on its top a large aluminium sheet of area ( 1 m^{2} ). Will he get an electric shock if he touches the metal sheet next morning? (c) The discharging current in the atmosphere due to the small conductivity of air is known to be 1800 A on an average Over the globe. Why then does the atmosphere not discharge itself completely in due course and become electrically neutral? In other words, what keeps the atmosphere charged? (d) What are the forms of energy into which the electrical energy of the atmosphere is dissipated during a lightning? (Hint: The earth has an electric field of about ( 100 mathrm{Vm}^{-1} ) at its surface in the downward direction, corresponding to a Surface charge density ( =-10^{-9} mathrm{Cm}^{-2} ). Due to the slight conductivity of the atmosphere up to about ( 50 mathrm{km} ) (beyond which it is good conductor), about ( +1800 mathrm{C} ) is pumped every second into the earth as a whole. The earth, however, does not get discharged since thunderstorms and lightning occurring continually allover the globe pump an equal amount of negative charge on the earth.) |
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| 228 | A capacitor of capacitance ( 9 n F ) having dielectric slab of ( varepsilon_{r}=2.4 ) dielectric strength ( 20 mathrm{MV} / mathrm{m} ) and ( boldsymbol{P . D .}=20 mathrm{V} ) Calculate area of plates. В . ( 4.2 times 10^{-4} mathrm{m}^{2} ) c. ( 1.4 times 10^{-4} m^{2} ) D. 2.4 ( times 10^{-4} m^{2} ) |
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| 229 | A parallel-plate capacitor is connected to a cell. Its positive plate ( A ) and its negative plate ( boldsymbol{B} ) have charges ( +boldsymbol{Q} ) and ( -Q ) respectively. A third plate ( C ) identical to ( A ) and ( B, ) with charge ( +Q ) is now introduced midway between ( boldsymbol{A} ) and ( B, ) parallel to them. Which of the following are correct? This question has multiple correct options A ( cdot ) The charge on the inner face of ( B ) is now ( -frac{3 Q}{2} ) B. There is no change in the potential difference between ( A ) and ( B ) C. The potential difference between ( A ) and ( C ) is one-third of the potential difference between ( B ) and ( C ) D. The charge on the inner face of ( A ) is now ( Q / 2 ) |
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| 230 | An electric circuit requires a total capacitance of ( 2 mu F ) across potential of ( mathbf{1 0 0 0} V ). Large number 1 ( mu boldsymbol{F} ) capacitances are available each of which would breakdown if the potential is more than ( 350 V ) How many capacitances are required to make the circuit. A .24 B . 20 c. 18 D. 12 |
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| 231 | A series combination of two capacitances of value 0.1 mu ( F ) and ( 1 mu F ) is connected with a source of voltage 500 volts. The potential difference in volts across the capacitor of value 0.1 mu ( F ) will be : ( mathbf{A} cdot 50 ) в. 500 c. 45.5 D. 454.5 |
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| 232 | Five identical plates are connected across a battery as shown. If the charge on plate 1 be ( +q, ) then the charges on the plates 2,3,4 and 5 are: ( mathbf{A} cdot-q,+q,-q,+q ) в. ( -2 q,+2 q,-2 q,+q ) c. ( -q,+2 q,-2 q,+q ) D. none of the above |
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| 233 | If ( 4 times 10^{20} e V ) is required to move a charge of ( 0.25 C ) between two points, the potential difference between these two points is: ( mathbf{A} cdot 256 V ) в. ( frac{1}{256} V ) ( mathbf{c} cdot 256 times 10^{+19} V ) D. ( 250 V ) |
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| 234 | A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are now moved apart by means of insulting handles: A. the charge on capacitors increases B. the voltage across the capacitors decreases c. the capacitance increases D. the electrostatic energy stored in the capacitor increases |
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| 235 | The negative gradient of potential is A. Electric force B. Torque C. Electric current D. Electric field intensity |
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| 236 | In the figure a potential of ( +1200 mathrm{V} ) is given to point ( A ) and point ( B ) is earthed,what is the potential at the point A . ( 100 mathrm{V} ) B. 200 c. ( 400 mathrm{v} ) D. 600 v |
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| 237 | In the figure, identical capacitors are connected in the given three configurations.The ratio of the total capacitancies in (i), (ii) and (iii) respectively, is : ( mathbf{A} cdot 3: 5: 5 ) B. 3: 3: 5 ( mathbf{c} cdot 5: 4: 4 ) ( mathbf{D} cdot 5: 5: 3 ) |
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| 238 | The work done in moving a charge of 5 coulombs from a point at 230 volts to another point at 240 volts is. A. 50 B . 15 c. 100 D. 500 |
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| 239 | A capacitor contains two square plates with side lengths ( 5.0 mathrm{cm} . ) The plates are separated by ( 2.0 mathrm{mm} . ) Dry air fills the space between the plates. Dry air has a dielectric constant of 1.00 and experiences dielectric breakdown when the electric field exceeds ( 3.010^{4} V / c m ) What is the magnitude of charge that can be stored on each plate before the capacitor exceeds its breakdown limit and sends a spark between the plates? ( mathbf{A} cdot 6.6 times 10^{-8} C ) В. ( 6.6 times 10^{-5} C ) c. ( 3.3 times 10^{-7} C ) D . 3.3 ( times 10^{-8} mathrm{C} ) E . ( 8.1 times 10^{-2} C ) |
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| 240 | Electricity at rest is called A. Dynamic Electricity B. Static Electricity C. Both (a) and (b) D. None of these |
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| 241 | 0 | 12 |
| 242 | In figure, a particle has mass ( boldsymbol{m}=mathbf{5} boldsymbol{g} ) and charge ( boldsymbol{q}^{prime}=mathbf{2} times mathbf{1 0}^{-mathbf{9}} boldsymbol{C} ) starts from rest at point ( a ) and moves in a straight line to point ( b ). What is its speed ( v ) at point ( b ? ) A ( .2 .65 mathrm{cms}^{-1} ) B. ( 3.65 mathrm{cms}^{-1} ) c. ( 4.65 mathrm{cms}^{-1} ) D. ( 5.65 mathrm{cms}^{-1} ) |
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| 243 | Two long conductors, separated by a distance ( boldsymbol{d} ) carry currents ( boldsymbol{I}_{1} ) and ( boldsymbol{I}_{2} ) in the same direction. They exert a force ( boldsymbol{F} ) on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increases to ( 3 d ). The new value of the force between them is: A . ( -2 F ) в. ( F / 3 ) ( mathrm{c} cdot-2 F / 3 ) D. ( -F / 3 ) |
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| 244 | Statement(A): Negative charges always move from a higher potential to lower potential point Statement (B): Electric potential is vector. A. A is true but B is false B. B is true but A is false c. Both A and B false D. Both A and R are true |
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| 245 | The arc ( A B ) with the centre ( C ) and the infinitely long wire having linear charge density ( lambda ) are lying in the same plane. The minimum amount of work to be done to move a point charge ( q_{0} ) from point ( A ) to ( B ) through a circular path ( A B ) of radius ( a ) is equal to: A ( cdot frac{q_{0}^{2}}{2 pi varepsilon_{0}} log left(frac{2}{3}right) ) в. ( frac{q_{0} lambda}{2 pi varepsilon_{0}} log left(frac{3}{2}right) ) c. ( frac{q_{0} lambda}{2 pi varepsilon_{0}} log left(frac{2}{3}right) ) D. ( frac{q_{0} lambda}{sqrt{2} pi varepsilon_{0}} ) |
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| 246 | Four identical plates ( 1,2,3, ) and 4 are placed parallel to each other at equal distance as shown in the figure. Plates 1 and 4 are joined together and the space between 2 and 3 is filled with a dielectric of dielectric constant ( k=2 ) The capacitance of the system between 1 and ( 3 & 2 ) and 4 are ( C_{1} ) and ( C_{2} ) respectively. The ratio ( C_{1} / C_{2} ) is : ( mathbf{A} cdot 5 ) ( overline{3} ) B. ( c cdot frac{3}{5} ) D. 5 7 |
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| 247 | Two capacitors of plate area ( A ) are joined as shown in the figure. Their central rigid part is movable. The capacity of the combination will be: A ( cdot frac{epsilon_{0} A}{a-b} ) в. ( frac{epsilon_{0} A}{a+b} ) c. ( frac{2 in_{0} A}{a+b} ) D. ( frac{a-b}{epsilon_{0} a} ) |
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| 248 | Two concentric shells have radii R and 2R, charges ( boldsymbol{q}_{A} ) and ( boldsymbol{q}_{B} ) and potentials ( 2 mathbf{V} ) and (3/2)V respectively. Now shell B is earthed and let charges on them become ( boldsymbol{q}_{A}^{prime} ) and ( boldsymbol{q}_{B}^{prime} . ) Then This question has multiple correct options B ( cdotleft|q_{A}^{prime}right| / q_{B}^{prime} mid=1 ) c. Potential of A after earthing becomes (3/2)V D. Potential difference between A and B after earthing becomes V/2 |
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| 249 | A conducting body 1 has some initial charge ( Q, ) and its capacitance is ( C . ) There are two other conducting bodies, 2 and ( 3, ) having capacitances: ( C_{2}=2 C ) and ( C_{3} rightarrow infty . ) Bodies 2 and 3 are initially uncharged. “Body 2 is touched with body ( 1 . ) Then, body 2 is removed from body 1 and touched with body 3 and then removed”. This process is repeated ( N ) times. Then, the charge on body 1 at the end must be : A ( cdot Q / 3^{N} ) B . ( Q / 3^{N-1} ) c. ( Q / N^{3} ) D. None |
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| 250 | A parallel-plate capacitor is charged from a cell and then disconnected from the cell. The separation between the plates is now doubled. This question has multiple correct options A. The potential difference between the plates will become double B. The field between the plates will not change. c. The energy of the capacitor doubles D. Some work will have to be done by an external agent on the plates. |
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| 251 | Q Type your question uniform field between the parallel plates as shown in figure. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. The electron enters the field at a point midway between the plates. Mass of electron is ( 9.1 times 10^{-31} k g . ) If the electron just misses the upper plate, the time of flight of the electron up to this instant is : A ( cdot 1.25 times 10^{-9} s ) в. ( 32.5 times 10^{-6} s ) C ( cdot 1.25 times 10^{-10} s ) D. ( 32.5 times 10^{-8} s ) |
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| 252 | A parallel plate capacitor of capacitance ( C ) is connected to a battery and is charge to a potential difference ( V . ) Another capacitor of capacitor ( 2 C ) is similarly charged to a potential difference ( 2 V . ) The charging battery is now disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is: A . zero B ( cdot(3 / 2) C V^{2} ) ( mathbf{c} cdot 25 / 6 C V^{2} ) ( mathbf{D} cdot(9 / 2) C V^{2} ) |
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| 253 | When two capacitors are joined in series the resultant capacity is ( 2.4 mu F ) and when the same two are joined in parallel the resultant capacity is ( 10 mu F ). Their individual capacities are : ( mathbf{A} cdot 7 mu F, 3 mu F ) в. ( 1 mu F, 9 mu F ) ( mathbf{c} cdot 6 mu F, 4 mu F ) D. ( 8 mu F, 2 mu F ) |
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| 254 | A charged spherical drop of mercury is in equilibrium in a plane horizontal air capacitor and the intensity of the electric field is ( 6 times 10^{4} V m^{-1} . ) If the charge on the drop is ( 8 times 10^{-18} C, ) the radius of the drop is : ( left[rho_{a i r}=1.29 k g / m^{3} ; rho_{H g}=13.6 times 10^{3}right. ) A ( cdot 0.95 times 10^{-8} m ) n в. ( 2.7 times 10^{-10} mathrm{m} ) c. ( 2.7 times 10^{-8} mathrm{m} ) D. ( 0.95 times 10^{-6} mathrm{m} ) |
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| 255 | Identical metal plates are located in air at equal distance ( d ) from one another The area of each plate is equal to ( A ). If the capacitance of the system between ( P ) and ( Q ) if the plates are interconnected as shown in the figure is given as ( frac{x}{2} varepsilon_{0} frac{A}{d} ) Find ( x: ) |
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| 256 | A dielectric is introduced in a charged and isolated parallel plate capacitor, which of the following remains unchanged? A. Energy B. Charge c. Electric field D. Potential difference |
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| 257 | The force experienced by a charged particle of charge ( q ) at (1,1,1) is A. ( -5 q ) в. ( 5 q hat{imath} ) c. ( 5 q(hat{i}+hat{j}) ) D. ( -5 q(hat{i}+hat{j}) ) |
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| 258 | Four equal charges ( +Q ) are placed at the four corners of a body of side ( a ) each. Work done in removing a charge ( -boldsymbol{Q} ) from its centre to infinity is A. zero В. ( frac{sqrt{2} Q^{2}}{4 pi varepsilon_{0} a} ) c. ( frac{sqrt{2} Q^{2}}{pi varepsilon_{0} a} ) ( ^{mathrm{D}} cdot frac{Q^{2}}{2 pi varepsilon_{0} a} ) |
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| 259 | The amount of charge stored in a capacitor is directly proportional to the voltage applied across the capacitor. A. True B. False |
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| 260 | Along the ( X ) -axis, three charges ( frac{q}{2},-q ) and ( frac{q}{2} ) are placed at ( x=0, x=a ) and ( x=2 a ) respectively. The resultant electric potential at ( x=a+r(text { if }, a<r) ) is : ( left(epsilon_{0} ) is the permittivity of free space) right. A ( cdot frac{q a}{4 pi epsilon_{0} r^{2}} ) в. ( frac{q a^{2}}{4 pi epsilon_{0} r^{3}} ) ( ^{mathbf{C}} cdot frac{qleft(a^{2} / 4right)}{4 pi epsilon_{0} r^{3}} ) D. ( frac{q}{4 pi epsilon_{0} r} ) |
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| 261 | Three charges all of ( +q ) are brought together so that they form an equilateral triangle, with a distance ( r ) between them. Determine the electrostatic potential |
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| 262 | Four capacitor are connected, as shown Calculate the equivalent capacitance between the points ( boldsymbol{P} ) and ( boldsymbol{Q} ) begin{tabular}{c|cc|c|c} hline ( mathbf{P} ) & & & & \ hline & & & & \ ( 2 mu mathbf{F} ) & ( 3 mu mathbf{F} ) & ( mathbf{5} mu mathbf{F} ) & ( mathbf{1 0 mu F} ) & \ hline end{tabular} |
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| 263 | The space between the plates of a parallel plate capacitor is filled with a dielectric’ whose ‘dielectric constant’ varies with distance as per the relation, ( boldsymbol{K}(boldsymbol{x})=boldsymbol{K}_{o}+boldsymbol{lambda} boldsymbol{x}(boldsymbol{lambda}=boldsymbol{a} text { constant }) ) The capacitance ( C, ) of this capacitor, would be related to its ‘vacuum’ capacitance ( C_{o} ) as per the relation: ( ^{mathbf{A}} cdot c=frac{lambda d}{ln left(1+k_{o} lambda dright)} C_{o} ) B. ( c=frac{lambda}{d cdot ln left(1+k_{o} lambda dright)} C_{o} ) ( ^{mathrm{c}} cdot_{C}=frac{lambda d}{ln left(1+lambda d / K_{o}right)} C_{o} ) D. ( c=frac{lambda}{d cdot ln left(1+k_{o} / lambda dright)} C_{o} ) |
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| 264 | An infinite number of charges ‘q’ each are placed along the ( x ) – axis at ( x=1, x=4 ) ( x=8 ) and ( s o ) on. If the distance are in meters calculate the electric potential at ( x=0 ) ( A cdot frac{3 q}{8 F C_{0}} ) B. ( frac{q}{2 pi_{0}} ) ( c cdot frac{2 q}{pi_{0} q} ) D. ( frac{49}{pi_{0} q} ) |
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| 265 | Two small spheres each carrying a charge ( q ) are placed ( r ) metre apart. If one of the spheres is taken around the other one in a circular path, the work done will be equal to : A. force between them ( x ) r B. force between them ( times 2 pi r ) c. force between them / r ( pi ) r D. zero |
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| 266 | Six capacitors each of capacitance of ( 2 mu F ) are connected as shown in the figure. The effective capacitance between ( A ) and ( B ) is: ( mathbf{A} cdot 12 mu F ) в. ( frac{8}{3} mu F ) ( c .6 mu F ) D ( frac{2}{3} mu F ) |
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| 267 | High frequency capacitor offers A. more resistance B. less resistance C. zero resistance D. None of these |
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| 268 | An infinite nonconducting sheet has a surface charge density ( boldsymbol{sigma}= ) ( 0.10 mu C / m^{2} ) on one side. How far apart are equipotential surfaces whose potentials differ by ( 50 V ? ) A. ( 8.8 mathrm{mm} ) B. ( 8.8 mathrm{cm} ) ( c .8 .8 m ) D. ( 8.8 mu m ) |
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| 269 | Figure shows three concentric thin spherical shells ( A, B, ) and ( C ) of radii ( R ) ( 2 R, ) and ( 3 R ) respectively. The shell B is earthed and ( A ) and ( C ) are given charges and ( 2 q ) respectively. If the charge on surfaces ( 1,2,3, ) and 4 are ( q_{1}, q_{2}, q_{3}, ) and ( q_{4} ) respectively, then match the following columns : |
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| 270 | What is the equivalent capacitance of the combination? |
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| 271 | toppr ócin Q Type your question conductor as shown. Now as the point charge ( Q ) is pushed away from conductor, the potential difference ( left(V_{A}-V_{B}right) ) between two points ( A ) and ( B ) within the cavity of sphere remains constant Reason The electric field due to charge on outer surface of conductor and outside the conductor is zero at all points inside the conductor A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 272 | ( underbrace{frac{i}{i}}{k} ) | 12 |
| 273 | Electric potential is : A. a scalar quantity B. a vector quantity C. neither scalar nor vector D. sometimes scalar and sometimes vector |
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| 274 | If an electron is released from rest at point ( p ) in the diagram, what will it do? A. Move to the right B. Move to the left C. Move toward the top of the screen D. Move toward the bottom of the screen |
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| 275 | Derive the formula for the electric potential energy of an electric dipole in a uniform electric field. |
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| 276 | Two fixed charges ( -2 Q ) and ( Q ) are located at the points with coordinates ( (-3 a, 0) ) and ( (+3 a, 0), ) respectively, in the xy plane. a. Show that all points in the xy plane where the electric potential due to the two charges is zero lie on a circle.Find its radius and the location of its center. b. Give the expression ( V(x) ) at a general point on the ( x ) -axis and sketch the function ( V(x) ) on the whole ( x ) -axis. c. If a particle of charge +q starts from rest at the center of the circle, show by a short quantitative argument that the particle eventually crosses the circle. Find its speed when it does so. |
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| 277 | The capacity and the energy stored in a charged parallel plate condenser with air between its plates are respectively ( C 0 ) and ( W 0 . ) If the air is replaced by glass (dielectric constant = 5) between the plates, the capacity of the plates and the energy stored in it will respectively be: |
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| 278 | Two identical spheres, one positively charged and the other negatively charged are held d cm apart. If the magnitude of the charges on the two spheres is equal, find the electric potential at a point midway on the line joining the centres of the two spheres. A. zero B. ( 10 mathrm{v} ) ( c .5 v ) D. ( 1.6 times 10^{-19} mathrm{V} ) |
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| 279 | Four identical charges are placed at the points (1,0,0),(0,1,0),(-1,0,0) and ( (0, ) -1,0) This question has multiple correct options A. The potential at the origin is zero. B. The field at the origin is zero c. The potential at all points on the z-axis, other than the origin, is zero. D. The field at all points on the z-axis, other than the origin, acts along the z-axis |
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| 280 | A electric charge ( 10^{-8} C ) is placed at the point ( (4 m, 7 m, 2 m) . ) At the point ( (1 m, 3 m, 2 m) ) the electric A. potential will be ( 18 V ) B. field has no ( Y ) -component c. field will be along ( Z ) -axis D. potential will be ( 1.8 V ) |
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| 281 | The effective capacity of the network between terminals A and B is- ( A cdot 6 mu F ) B. ( 20 mu F ) ( mathbf{c} cdot 3 mu F ) D. ( 10 mu F ) |
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| 282 | The radius of a nucleus of an atom ( (Z=50) ) is ( 9 times 10^{-10} m ) then potential on its surface, will be: A . ( 80 V ) B. ( 8 k V ) ( mathrm{c} .9 mathrm{V} ) D. ( 9 k V ) |
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| 283 | Two infinitely long parallel plates of equal areas ( 6 mathrm{cm}^{2} ) are separated by a distance of ( 1 mathrm{cm} . ) While one of the plates has a charge of ( +10 n C ) and the other has ( -10 n C . ) The magnitude of the electric field between the plates, if ( varepsilon_{0}= ) ( frac{10^{-9}}{36 pi} F / m ) is? A. ( 0.6 pi V / m ) в. ( 6 pi k V / m ) c. ( 600 pi k V / m ) D. ( 60 pi V / m ) E . ( 6 pi ) |
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| 284 | The 90 pF capacitor is connected to a 12 V battery. How many electrons are transferred from one plate to another? ( mathbf{A} cdot 1.1 times 10^{9} ) B . ( 6.7 times 10^{9} ) ( mathrm{c} cdot 4 times 10^{19} ) D . ( 5 times 10^{19} ) |
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| 285 | There are two uncharged identical metallic spheres 1 and 2 of radius ( r ) separated by a distance ( d(d>>r) . A ) charged metallic sphere of same radius having charge ( q ) is touched with one of the sphere. After sometime it is moved away from the system. Now the uncharged sphere is earthed. Charge on earthed sphere is : ( A cdot+frac{q}{2} frac{q}{2} ) B. ( -frac{q}{2} ) c. ( -frac{q r}{2 d} ) D. ( -frac{q d}{2 r} ) |
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| 286 | The dimensional formula of electric potential is given by ( mathbf{A} cdotleft[M L^{2} T^{-3} A^{-1}right] ) B. ( left[M L^{2} T^{-2} A^{-1}right] ) ( mathbf{c} cdotleft[M L^{2} T^{-1} A^{-1}right] ) D. ( left[M L^{2} T^{-2}right] ) |
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| 287 | In a parallel plate capacitor, the capacity increases if : A. area of the plate is decreased B. distance between the plates increases C . area of the plate increases D. dielectric constant decrease |
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| 288 | What is the electric potential at the centre of square of side 1 m? The charges ( 1 times 10^{-8} C,-2 times 10^{-8} C, 3 times ) ( 10^{-8} C ) and ( 2 times 10^{-8} C ) are placed at the corners of the square. ( mathbf{A} cdot 205 V ) B. ( 308 V ) ( c .509 V ) D. ( 110 V ) |
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| 289 | When a ( 15 V ) dc source was applied across a choke coild then a current of 5 Amp flows in it. If the same coil is connected to a ( 15 V, 50 ) rad/s ac source a current of ( 3 A m p ) flows in the circuit and its resonance frequency if a ( 2500 mu f ) capacitor is connected in series with the coil. |
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| 290 | In the following circuit potential at point ‘A’ is zero.Which resistance consumes maximum power? |
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| 291 | The following arrangement consists of five identical metal plates. Area of each plate is ( A ) and separation between the successive plates is d. The capacitance between ( P ) and A. ( frac{5 varepsilon_{0} A}{d} ) В. ( frac{7}{3} varepsilon_{0} frac{A}{d} ) c. ( frac{4}{3} frac{varepsilon_{0} A}{d} ) D. ( frac{5}{3} frac{varepsilon_{0} A}{d} ) |
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| 292 | Assertion From the relation ( C=frac{q}{V} . ) We can say that, if more charge q is given q is given to a conductor, its capacity should increase. Reason Ratio ( frac{q}{V} ) will remain constant for a given conductor. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 293 | Which of the following is not dielectric materials? A. Silicon dioxide B. Silicon nitride c. Titanium oxide D. None of the above |
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| 294 | An electron of mass ( M_{e}, ) initially at rest moves through a certain distance in a uniform electric field in time ( t_{1} . A ) proton of mass ( M_{p} ) also intially at rest, takes time ( t_{2} ) to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio ( t_{2} / t_{1} ) is nearly equal to: A . 1 в. ( sqrt{frac{M_{p}}{M_{e}}} ) c. ( sqrt{frac{M_{e}}{M_{p}}} ) D. 1836 |
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| 295 | In bringing an electron towards another electron, the electrostatic potential energy of the system: A . decreases B. increases c. remains same D. becomes zero |
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| 296 | When a dielectric is introduced between the plates of a condenser, the capacity of condenser: A . increases B. decreases c. remains same D. none of these |
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| 297 | Select the correct statements: A. The electric lines of force are always closed curves. B. Electric line of forced is parallel to equipotential surface C. Electric line of force is perpendicular to equipotential surface. D. Electric line of force is always the path of a positively charged particle. |
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| 298 | Two positive point charges are of ( 12 C ) and ( 8 C ) are ( 10 mathrm{cm} ) apart from each other The work done in bringing them ( 4 c m ) closer is A . ( 5.8 J ) в. ( 13 e V ) c. ( 5.8 e V ) D. ( 13 J ) |
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| 299 | Three identical dipoles with charges ( q ) and -q and separation between the charges are placed at the corners of an equilateral triangle of side d as shown in Fig. ( 3.123 . ) Find the interaction energy of the system ( (a< ) |
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| 300 | The capacitance of a parallel plate capacitor with air as medium is ( 3 mu mathrm{F} ) As a dielectric is introduced between the plates, the capacitance becomes 15 ( mu mathrm{F} . ) The permittivity of the medium in ( C^{2} N^{-1} m^{-2} ) is A . ( 8.15 times 10^{-11} ) В. ( 0.44 times 10^{-10} ) C . ( 15.2 times 10^{12} ) D. ( 1.6 times 10^{-14} ) |
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| 301 | Electric Potential on the surface of a charged spherical shell of radius ( 10 mathrm{cm} ) is 50 volt. Find the value of electric potential at a distance of ( 20 mathrm{cm} ) from the center of spherical shell. |
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| 302 | A conductor ( A ) is given a charge of amount ( +mathrm{Q} ) and then placed inside a deep metal cab ( mathrm{B} ), without touching it: This question has multiple correct options A. the potential of A does not change when it is placed inside B. if B is earthed, ( +Q ) amount of charge will flow from it into the earth ( mathrm{C} ). if ( mathrm{B} ) is earthed, the potential of ( mathrm{A} ) will be reduced D. either(b) or (c) are true, or both are true only if the outer surface of B is connected to the earth and not its inner surface |
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| 303 | If we increase the distance between two plates of the capacitor, the capacitance will A. decrease B. remain same c. increase D. first decrease then increase |
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| 304 | Define energy density of the median surrounding a charged conductor and state its formula. | 12 |
| 305 | Two parallel metal plates having charges ( +Q ) and ( -Q ) face each other at a certain distance between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will : A. become zero B. increase c. decrease D. remains same |
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| 306 | UUUOOO 70. The capacitor of an oscillatory circuit of frequency 10000 is enclosed in a container. When the containeris evacuated the frequency changes by 50 Hz, the dielectric constant of the gas (a) 1.1 (b) 1.01 (c) 1.001 (d) 1.0001 |
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| 307 | A charge ( +q ) is placed at the origin 0 of ( X-Y ) axes as shown in the figure. The work done in taking a charge ( Q ) from ( A ) to B along the straight line AB is: A ( cdot frac{q Q}{4 pi epsilon_{0}}left(frac{a-b}{a b}right) ) В ( cdot frac{q Q}{4 pi epsilon_{0}}left(frac{b-a}{a b}right) ) c. ( frac{q Q}{4 pi epsilon_{0}}left(frac{b}{a^{2}}-frac{1}{b}right) ) D. ( frac{q Q}{4 pi epsilon_{0}}left(frac{a}{b^{2}}-frac{1}{b}right) ) |
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| 308 | Illustrate a condition in which : Electric field is zero but potential is not zero. |
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| 309 | toppr LOGIN JolN Now Q Type your question What happens to the charge on the plates, the voltage across the plates, and the capacitance of the capacitor as a result of moving the plates closer together? ( A ) begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor } & Values after Plates are Moved Closer Together \ hline Charges on Plates & same \ Voltage Across Plates Capacitance & larger larger \ hline end{tabular} B. begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor } & Values after Plates are Moved Closer Together \ hline Charges on Plates & same \ Voltage Across Plates & smaller \ Capacitance & larger \ hline end{tabular} ( c ) begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor } & Values after Plates are Moved Closer Together \ hline Charges on Plates & larger \ Voltage Across Plates Capacitance & same same \ hline end{tabular} D. begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor } & Values after Plates are Moved Closer Together \ hline Charges on Plates & larger \ Voltage Across Plates & same \ Capacitance & larger \ hline end{tabular} E begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor } & Values after Plates are Moved Closer Together \ hline Charges on Plates & larger \ Voltage Across Plates Capacitance & larger larger \ hline end{tabular} |
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| 310 | A condenser is charged and then battery is removed. A dielectric plate is put between the plates of condenser, then correct statement is A. Q is constant, v and U decrease B. Q is constant, V increases U decreases c. Q increases, v decreases U increases D. ( Q, v ) and ( U ) increase |
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| 311 | in fig consists of two horizontal conducting plates of equal area A. The bottom plate rests on a fixed support and the top plate is suspended by four springs with spring constant ( mathrm{k} ) positioned at each of the four corners of the plate as shown in Fig. When uncharged, the plates are separated by a distance ( z_{0} . ) A battery is connected to the plates and produces a potential difference V between them. This causes the plate separation to decrease to z. Neglect any fringing effects. Find the condition of stable equilibrium: A. z shall have positive root B. z shall negative root c. no dependence on value of ( z ) D. none of these |
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| 312 | Define the term electric potential. State its S.I. unit. |
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| 313 | Which of the following is not showing the essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding? A. Electrostatic field lines can end on charges and conductors have free charges B. Magnetic field lines can end but conductors cannot end them. c. Lines of magnetic field cannot end on any material and perfect shielding is not possible. D. shells of high permeability materials can be used to divert lines of magnetic field from the interior region |
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| 314 | The capacitance of a capacitor becomes ( frac{7}{6} ) times its original value if a dielectric slab of thickness, ( t=frac{2}{3} d ) is introduced in between the plates. ( d ) is the separation between the plates. The dielectric constant of the dielectric slab is: ( mathbf{A} cdot frac{14}{11} ) B. ( frac{11}{14} ) ( c cdot frac{7}{11} ) D. ( frac{11}{7} ) |
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| 315 | A spherical body P has a positive charge on it. It attracts an another sphere ( mathrm{Q} ) placed near it. The sphere ( Q ) is A. negatively charge B. positively charge c. neutral D. may be negative or neutral |
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| 316 | See the diagram. Area of each plate is ( 2.0 m^{2} ) and ( d=2 times 10 times 10^{-3} m . ) charge of ( 8.85 times 10^{-8} C ) is given to ( Q ) Then the potential of ( Q ) becomes: ( mathbf{A} cdot 13 V ) B. 10v c. ( 66.7 mathrm{V} ) D. ( 8.825 v ) |
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| 317 | A capacitor of capacitance ( C=4 mu F ) is connected as shown in figure. If internal resistance of the cell is ( 0.5 . ) The charge on the capacitor plates is A. zero 3. ( 8 mu ) C ( c cdot 4 mu C ) ( D cdot 6 mu C ) |
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| 318 | A metallic sphere of radius ( 18 mathrm{cm} ) has been given a charge of ( 5 times 10^{-6} ) C. The energy of the charged conductor is: A. 0.25 J ( J ) в. 0.6 .5 c. ( 1.2 J ) D. 2.4J |
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| 319 | Three identical capacitors, each of capacitance ( C, ) are connected in series with a battery of emf ( V ) and get fully charged. Now, the battery is removed and the capacitors are connected in parallel with positive terminals are one point and negative terminals at other point. Then, the common potential will be : A. ( V ) в. ( 3 V ) c. ( frac{V}{3} ) D. |
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| 320 | Given that ( boldsymbol{E}=left(left(mathbf{3} boldsymbol{x}^{2}+boldsymbol{y}right) hat{boldsymbol{i}}+right. ) ( boldsymbol{x} hat{boldsymbol{y}}) boldsymbol{k} boldsymbol{V} / boldsymbol{m}, ) find the work done in moving a ( -2 mu C ) charge from (0,5,0) to (2,-1,0) by taking the path: ( boldsymbol{y}=mathbf{5}-mathbf{3} boldsymbol{x} ) A . ( 12 J ) в. ( 12 m J ) ( mathbf{c} cdot 12 k J ) D. ( 12 mu J ) |
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| 321 | Three particles, each having a charge of ( 10 mu C ) are placed at the corners of an equilateral triangle of side ( 10 mathrm{cm} ). The electronic potential energy of the system is: ( left(text { Given } frac{1}{4 pi varepsilon_{0}}=9 times 10^{9} N-right. ) ( left.m^{2} / C^{2}right) ) A. Zero B. Infinite c. 27 D. ( 100 J ) |
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| 322 | Which of the following statements is false for a perfect conductor? A. The surface of the conductor is an equipotential surface. B. The electric field just outside the surface of a conductor is perpendicular to the surface. C. The charge carried by a conductor is always uniformly distributed over the surface of the conductor D. None of these |
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| 323 | Calculate the ratio of the equivalent capacitance of the circuit when two identical capacitors are in series to that when they are in parallel? A ( cdot frac{1}{4} ) B. ( frac{1}{2} ) c. D. 2 E . 4 |
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| 324 | A quantity ( X ) is given by ( epsilon_{0} L frac{Delta V}{Delta T} ) where so is the permittivity of the free space, is a length. ( Delta V ) is a potential difference and ( Delta t ) is a time interval. The dimensional formula for ( X ) is the same as that of A . resistance B. charge c. voltage D. current |
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| 325 | Two circular plates of radius ( R ) are kept at distance ( h ) to make a parallel plate capacitor as shown in the figure. Then the capacitance of this capacitor is: A ( cdot frac{varepsilon_{0} pi R^{2}}{h} ) B. ( frac{varepsilon_{0} 2 pi R}{h} ) c. ( frac{2 varepsilon_{0} 2 pi R^{2}}{h} ) D. none of these |
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| 326 | In order to increase the capacity of parallel plate condenser one should introduce between the plates, a sheet of A . mica B. tin c. copper D. stainless steel |
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| 327 | The electric potential at a point in free space due to a charge ( Q ) coulomb is ( Q times 10^{11} mathrm{V} . ) The electric field at that point is: A . 12 ( pi varepsilon_{0} Q times 10^{22} mathrm{Vm}^{-1} ) В . ( 4 pi varepsilon_{0} Q times 10^{22} V m^{-1} ) C . ( 12 pi varepsilon_{0} Q times 10^{20} mathrm{Vm}^{-1} ) D. ( 4 pi varepsilon_{0} Q times 10^{20} V m^{-1} ) |
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| 328 | Four charges, all of the same magnitude placed at the four corners of a square. At centre of the square, the potential is ( V ) and the field is ( E . B y ) suitable choices of the signs of four charges, which of the following can be obtained? This question has multiple correct options A. ( V=0, E=0 ) B. ( V=0, E neq 0 ) c. ( V neq 0, E=0 ) D. ( V neq 0, E neq 0 ) |
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| 329 | In hydrogen atom electron of charge ( -e ) and mass m revolves round the nucleus in a circular orbit of radius r. The electrostatic potential energy of the electron is ( frac{1}{4 pi varepsilon_{0}} ) times A ( cdot frac{-e}{r} ) B. ( frac{-e^{2}}{r} ) c. ( frac{e^{2}}{r} ) D. ( frac{-m e^{2}}{r} ) |
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| 330 | An elliptical cavity is carved out in a perfect conductor. A positive charge q is placed at the centre of the cavity. The points ( A ) and ( B ) are shown in figure. Then This question has multiple correct options A. electric field near A in the cavity = electric field near in the cavity B. charge density at ( A= ) charge density at ( B ) C. potential at ( A= ) potential at ( B ) D. total electric field flux through the surface of the cavity ( =frac{q}{varepsilon_{0}} ) |
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| 331 | Identical metal plates are located in air at equal distance ( d ) from one another The area of each plate is equal to ( A ). If the capacitance of the system between ( P ) and ( Q ) if the plates are interconnected as shown in the figure is given as ( frac{x}{3} varepsilon_{0} frac{A}{d} ) Find ( x: ) |
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| 332 | True or False : Three positive (red) and three negative (blue) point charges are arranged symmetrically around a circle centered on point ( P ) as shown in the diagram. Al point charges are of the same magnitude. Electric Field at ( mathrm{P} ) will be zero while electric potential at point ( P ) will be non zero. A. True B. False |
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| 333 | Q Type your question below. All point charges are of the same magnitude. Which table gives the best description |
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| 334 | For an irregularly shaped charged conductor the potential is : A. more at the flat parts B. more at the spherical parts C. more at the sharp edges D. same everywhere |
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| 335 | A parallel plate capacitor with circular plates and a capacitance ( C ) has the radius of each plate doubled and the distance between the plates doubled. What is the new capacitance? ( ^{A} cdot frac{C}{2} ) в. ( C ) ( c cdot 2 C ) D. ( 4 C ) |
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| 336 | Air filled capacitor of capacitance ( 2 mu boldsymbol{F} ) is filled with three dielectric material of dielectric constants ( boldsymbol{K}_{mathbf{1}}=mathbf{4}, boldsymbol{K}_{mathbf{2}}= ) 4 and ( K_{3}=6 ) as shown in the figure. The new capacitance of the capacitors is ( mathbf{A} cdot 50 mu F ) в. ( 2 mu F ) ( c cdot 20 mu F ) D. ( 10 mu F ) |
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| 337 | : | 12 |
| 338 | The potential at ( P ) due to induced charge is ( ^{text {A }} cdot_{K q}left(frac{1}{r_{1}}-frac{1}{r_{2}}right) ) в. ( _{K q}left(frac{1}{r_{1}}+frac{1}{r_{2}}right) ) ( ^{text {c. }} K qleft(-frac{1}{r_{1}}+frac{1}{r_{2}}right) ) D. ( frac{K q}{r_{1}} ) |
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| 339 | Figure shows three circular arcs, each of radius ( R ) and total charge as indicated. The net electric potential at the center of curvature is : ( ^{A} cdot frac{Q}{2 pi varepsilon_{0} R} ) ( B ) c. ( frac{3 Q}{32 pi varepsilon_{0} R} ) D. none of these |
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| 340 | On moving a charge of 20 coulombs by ( 2 mathrm{cm}, 2 mathrm{J} ) of work is done, then the potential difference between the points is: A . ( 0.1 mathrm{v} ) B. 8 ( c cdot 2 v ) D. 0.5 |
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| 341 | (a) A conductor ( A ) with a cavity as shown in Fig. ( (a) ) is given a charge ( Q ) Show that the entire charge must appear on the outer surface of the conductor. (b) Another conductor ( B ) with charge ( q ) is inserted into the cavity keeping ( boldsymbol{B} ) insulated from ( A . ) Show that the total charge on the outside surface of ( boldsymbol{A} ) is ( boldsymbol{Q}+boldsymbol{q} ) (c) A sensitive instrument is to be shielded from the strong electrostatic fields in its environment. Suggest a possible way. ( (mathbf{a}) ) ( mathbf{b} ) |
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| 342 | A charge ( +q ) is fixed at each of the points ( boldsymbol{x}=boldsymbol{x}_{0}, boldsymbol{x}=mathbf{3} boldsymbol{x}_{0}, boldsymbol{x}=mathbf{5} boldsymbol{x}_{0} dots dots ) up to infinity on ( x ) axis and a charge ( (-q) ) is fixed on each of points of ( boldsymbol{x}=mathbf{2} boldsymbol{x}_{0}, boldsymbol{x}= ) ( mathbf{4} boldsymbol{x}_{0}, boldsymbol{x}=boldsymbol{6} boldsymbol{x}_{0} ldots ldots . . ) up to infinity, here ( boldsymbol{x}_{mathbf{0}} ) is a positive constant. Take the potential at a point due to a charge ( Q ) at a distance ( r ) from it ( frac{Q}{4 pi varepsilon_{0} r}, ) then the potential at the origin due to above system of charges will be : A . 0 B. ( infty ) c. ( frac{q log _{e} 2}{4 pi varepsilon_{a}} ) D. ( frac{q}{8 pi varepsilon_{0} x_{0} log _{e} 2} ) |
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| 343 | On removing the dielectric from a charged condenser, its energy A. increase B. remains unchanged c. decreases D. none of these |
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| 344 | A capacitor acquires a potential difference of ( 200 mathrm{V} ) when ( 10^{12} ) electrons are taken from one plate and placed on the other plate. Its capacitance is: A ( cdot 2 times 10^{-10} F ) В. ( 4 times 10^{-10} F ) c. ( 8 times 10^{-10} F ) D. ( 12 times 10^{-10} F ) |
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| 345 | Q Type your question. is earthed. ( C ) is the common center of ( A ) and ( B . ) Study the following statements. Which of the following statements are correct? The potential at a distance ( r ) from ( C ) where ( a leq r leq b, i s frac{1}{4 pi varepsilon_{0}}left(frac{Q}{r}right) ) |
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| 346 | Assertion Two equipotential surfaces cannot cut each other. Reason Two equipotential surfaces are paralle to each other. A. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion. B. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion. C. If Assertion is correct but Reason is incorrect. D. If Assertion is incorrect but Reason is correct. |
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| 347 | An alpha particle of ( 5 mathrm{MeV} ) at a large distance proceeds towards a gold nucleus ( (Z=79) ) to make a head on collision. The closest distance of approach from the centre of gold nucleus is: A. ( 20 f m ) B. 15 fm c. ( 10 f m ) D. 45 fm |
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| 348 | Two circular plates of radius ( 0.1 mathrm{m} ) are used to form a parallel plate capacitor if displacement current between the plates is ( 2 pi ) ampere, then find magnetic field produced by displacement current ( 4 mathrm{cm} ) from the axis of the plates. |
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| 349 | Charges of ( +frac{10}{3} times 10^{-9} C ) are placed at each of the four corners of a square of side ( 8 mathrm{cm} . ) The potential at the intersection of the diagonals is A. ( 150 sqrt{2} ) volt в. ( 1500 sqrt{2} ) volt c. ( 900 sqrt{2} ) volt D. 900 volt |
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| 350 | A capacitor of ( 10 mu F ) charged upto ( 250 mathrm{V} ) is connected in parallel with another capacitor of ( 5 mu F ) charged upto ( 100 mathrm{V} ) The common potential is : A . 200 B. 300 c. ( 400 mathrm{v} ) D. 500 |
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| 351 | Find identical capacitor plates, each of area ( A, ) are arranged such that adjacent plates are at a distance ( ^{prime} d^{prime} ) apart, the plates are connected to a source of emf ( V ) as shown in figure. The charge on plate 1 is and that on plate 4 is |
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| 352 | Three charges ( +q,-q ) and ( -q ) are kept at the vertices of an equilateral triangle of ( 10 mathrm{cm} ) side. The potential at the mid point in between ( -q,-q, ) if ( q=5 mu C ) is : A . ( -6.4 times 10^{5} V ) B. ( -12.8 times 10^{4} V ) c. ( -6.4 times 10^{4} V ) D. ( -12.8 times 10^{5} V ) |
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| 353 | Two conducting spheres, each given a charge ( q ) are kept far apart as shown. The amount of charge that crosses the switch ( S_{1}, ) where it is closed, is (the connection between the spheres is conducting) A . ( underline{q} ) 3 в. ( frac{2 q}{3} ) ( c cdot frac{3 q}{4} ) D. Zero |
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| 354 | Two positive charges ( q ) and ( q ) are placed at the diagonally opposite corners of a square and two negative charges ( -q ) and ( -q ) are placed at the other two corners of the square. Then at the centre of the square the resultant electric intensity and the net electric potential Vare A. ( E neq 0, V=0 ) в. ( E=0, V=0 ) c. ( E=0, V neq 0 ) D. ( E neq 0, V neq 0 ) |
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| 355 | The maximum and minimum resultant capacity that can be obtained with ( 2 mu F, 3 mu F ) and ( 6 mu F ) are respectively: A. ( 11 mu F, 1 mu F ) в. ( 11 mu F, 6 mu F ) c. ( 11 mu F, 2 mu F ) D. ( 11 mu F, 4 mu F ) |
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| 356 | What amount of work is done in moving a charge of 4 coulombs from a point 220 volts to a point at 230 volts? | 12 |
| 357 | A parallel plate capacitor of capacitance ( 6 mu F ) in air and ( 60 mu F ) When dielectric is introduced. What is the dielectric constant of the medium.? A . 0.4 в. 0.1 c. 0.77 D. 0.25 |
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| 358 | In the electric field of charge ( Q, ) another charge is carried from ( A ) to ( B . A ) to ( C, A ) to Dand A to E, then work done will be A. minimum along path AB B. minimum along path AD c. minimum along path AE D. zero along all the paths |
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| 359 | The capacitors of three capacities are in the ratio ( 1: 2: 3 . ) Their equivalent capacity when connected in parallel is ( frac{60}{11} mu F ) more than that when connected in series. The individual capacities are : ( A cdot 4,6,7 ) B. 1,2,3 c. 2,3,4 D. 1,3,6 |
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| 360 | The electric field at a distance ( frac{3 R}{2} ) from the centre of a charged conducting spherical shell of radius ( mathrm{R} ) is ( mathrm{E} ). The electric field at a distance ( frac{boldsymbol{R}}{mathbf{2}} ) from the centre of the sphere is : A. zero B. E c. ( frac{E}{2} ) D. ( frac{E}{3} ) |
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| 361 | Equipotentials surfaces are shown in figure a and b. The field is uniform in A . a only B. b only ( c cdot a ) and ( b ) D. none |
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| 362 | A dense sphere of mass ( M ) is placed at the centre of a circle of radius ( R ). Find the work done, when a particle of mass ( m ) is brought from ( A ) to ( B ) along a circle as shown in the figure. A . zer в. ( frac{G M m}{R} ) c. ( -frac{G M m}{R} ) D. ( frac{2 G M m}{B} ) |
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| 363 | Two condensers of capacities ( 10 mu F ) and ( 20 mu F ) have potential differences of ( 20 mathrm{V} ) and ( 10 mathrm{V} ) respectively. The total charge is A ( .200 mu C ) в. ( 600 mu C ) c. ( 400 mu C ) D. zero |
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| 364 | An isolated conducting sphere whose radius ( R=1 m ) has a charge ( q=frac{1}{9} n C ) The energy density at the surface of the sphere is: A ( cdot frac{varepsilon_{0}}{2} J / m^{3} ) B . ( varepsilon_{0} J / m^{3} ) ( mathbf{c} cdot 2 varepsilon_{0} J / m^{3} ) D. ( frac{varepsilon_{0}}{3} J / m^{3} ) |
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| 365 | In the arrangement shown in fig. plate has a charge equal to ( 60 mu C ) The ratio ( d_{1} / d_{2} ) is ( 2 . ) Then ( q_{1}=_{-} ) ( q_{2}=_{-}– ) ( mathbf{q}_{3}=_{-}- ) ( boldsymbol{q}_{4}=_{-}– ) ( boldsymbol{q}_{5}=– ) ( boldsymbol{q}_{6}=_{-}- ) |
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| 366 | In the given circuit the potential at point ( boldsymbol{E} ) is: A. Zero B. ( -8 V ) ( c cdot-frac{4}{3} V ) ( D cdot underline{4}-v ) |
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| 367 | Two points ( P ) and ( Q ) are maintained at the potential of ( 10 ~ V ) and ( -4 V ) respectively. The work done in moving 100 electrons from ( P ) to ( Q ) is: A. ( -19 times 10^{-7} J ) ( J ) В. ( 9.60 times 10^{-17} J ) c. ( -2.24 times 10^{-16} J ) D. 2.24 ( times 10^{-16} mathrm{J} ) |
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| 368 | Three capacitances, each of ( 3 mu F, ) are provided. These cannot be combined to provide the resultant capacitance of : A ( .1 mu F ) в. ( 2 mu F ) c. ( 4.5 mu F ) D. ( 6 mu F ) |
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| 369 | For the given circuit, select the correct alternative(s) This question has multiple correct options A. The equivalent capacitance between points ( 1 & 2 ) is ( frac{15 C}{11} ) B. The equivalent capacitance between points ( 3 & 6 ) is ( frac{5 C}{3} ) C. The equivalent capacitance between points ( 1 & 3 ) is ( frac{15 C}{14} ) D. The equivalent capacitance between points 3 & 5 is ( frac{14 C C}{15} ) |
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| 370 | Figure shows equi-potential surfaces for a two charges system. At which of the labeled points point will an electron have the highest potential energy? A. Point ( A ) B. Point ( B ) ( c . ) Point ( C ) D. Point ( D ) |
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| 371 | Three identical large metal plates of area ( A ) are small at distances ( d ) and ( 2 d ) from each other. Top metal plate is uncharged, while the other metal plates have charges ( +Q ) and ( -Q . ) Top and bottom metal plates are connected by switch ( S ) through a resistor of unknown resistance. What energy (in mJ) is dissipated in the resistor when switch is closed? (given: ( left.frac{epsilon_{0} A}{d}=6 mu F, Q=60 mu Cright) ) |
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| 372 | When a dielectric slab of thickness ( 4 mathrm{cm} ) is introduced between the plates of parallel plate condenser, it is found that the distance between the plates has to be increased by ( 3 mathrm{cm} ) to restore the capacity to it’s original value. The dielectric constant of the slab is A ( cdot frac{1}{4} ) B. 4 ( c .3 ) D. |
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| 373 | joule coulomb ( ^{-1} ) is same as | 12 |
| 374 | When an additional charge of ( 2 C ) is given to a capacitor, energy stored in it is increased by ( 21 % ). The original charge of the capacitor is : A . ( 30 mathrm{c} ) B. ( 40 mathrm{c} ) c. ( 10 c ) D. ( 20 mathrm{c} ) |
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| 375 | In the electric field due to a point charge ( boldsymbol{q}, ) a test charge is carried from ( A ) to the points ( B, C, D ) and ( E ) lying on the same circle around ( q ). The work done is A. the least along ( A B ) B. the least along ( A D ) C. zero along any one of the paths ( A B, A D, A C ) and ( A E ) D. the least along ( A E ). |
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| 376 | Given the arrangement of charge below and the point ( P, ) what do we know for sure? The distance between adjacent charges is the same for all and the same as the distance from the nearest charges to point ( P ) ( left(begin{array}{ll}1.0 & cend{array}right) quadleft(begin{array}{ll}1.0 & cend{array}right) quad ) op A. The electric potential at point ( P ) is positive. B. The electric potential at point ( P ) is negative. c. The electric potential at point ( P ) is directed down and to the right. D. The electric potential at point P is directed up and to the left E. The electric potential at point P is zero. |
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| 377 | To obtain ( 3 mu F ) capacity from three capacitors of ( 2 mu F ) each, they will be arranged as follows: A. all the three in series B. all the three in parallel C. two capacitors in series and the third in parallel with the combination of first two D. two capacitors in parallel and the third in series with the combination of first two |
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| 378 | Three charges ( Q,+q ) and ( +q ) are placed at the vertices of a right-angled isosceles triangle as shown.The net electrostatic energy of the configuration is zero if ( Q ) is equal to : A ( cdot frac{-q}{1+sqrt{2}} ) B. ( frac{-2 q}{2+sqrt{2}} ) ( c cdot-2 q ) ( D cdot+a ) |
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| 379 | Now consider two identical infinite cylinders, parallel to each other, posed at a distance ( d>2 a ). Find the potential energy of the system (per unit length) ( ^{mathrm{A}} cdot frac{-pi rho^{2} a^{4}}{2 epsilon_{0}}left(log frac{d}{a}+0.25right) ) ( ^{mathbf{B}} cdot frac{-pi rho^{2} a^{4}}{2 epsilon_{0}}left(log frac{d}{a}+0.5right) ) ( ^{mathbf{C}} cdot frac{-pi rho^{2} a^{4}}{2 epsilon_{0}}left(log frac{d}{a}+0.75right) ) ( ^{mathrm{D} cdot} frac{-pi rho^{2} a^{4}}{2 epsilon_{0}}left(log frac{d}{a}+1right) ) |
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| 380 | When a ( 2 mu mathrm{C} ) charge is carried from point ( A ) to point ( B, ) the amount of work done by the electric field is ( 50 mu ). What is the potential difference and which point is at a higher potential? A ( .25 V, B ) в. ( 25 V, A ) ( c cdot 20 V, B ) D. Both are at same potential |
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| 381 | A variable air capacitor has 11 movable plates and 12 stationary plates, The area of each plate is ( 0.0015 m^{2} ) and separation between opposite plates is ( 0.001 m . ) The maximum capacitance of the capacitor is A . ( 292.2 F ) В. ( 292.2 mathrm{mF} ) c. ( 292 mu F ) D. 292 p |
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| 382 | A positively charged sphere suspended with a silk thread is slowly pushed in a metal bucket. After its insertion the lid is closed. What will be the electric field intensity inside when the sphere has touched the bucket? ( (sigma ) is the surface charge density of sphere) A. zero в. ( frac{sigma}{2 varepsilon_{0}} ) c. ( frac{sigma}{varepsilon_{0}} ) D. None of these |
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| 383 | A silicon diode has a “knee voltage of threshold voltage” value of ( 0.7 mathrm{V} ). This ( mathrm{Si} ) diode is connected in a circuit as shown in the figure Potential ( V_{0} ) of point ( p ) in the circuit will |
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| 384 | What is the capacity of a conductor? Explain the principle of a capacitor |
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| 385 | Three charges, each ( +q ), are placed at the corners of an isosceles triangle ( A B C ) of sides ( B C ) and ( A C, 2 a . D ) and ( E ) are the mid points of ( B C ) and ( C A ). The work done in taking a charge ( Q ) from ( D ) to ( boldsymbol{E} ) is : A ( cdot frac{e q Q}{8 pi epsilon_{0} a} ) в. ( frac{q Q}{4 pi epsilon_{0} a} ) c. zero D. ( frac{3 q Q}{4 pi epsilon_{n} a} ) |
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| 386 | The figure shows two identical paralle plate capacitors connected to a battery with the switch ( S ) closed. The switch is now opened and the free space between the plates of the capacitors is filled with a dielectric of dielectric constant (or relative permittivity) 3.Find the ratio of the total electrostatic energy stored in both capacitors before and after the introduction of the dielectric. ( A cdot frac{2}{3} ) B . 5 ( overline{3} ) ( c cdot 3 ) ( overline{5} ) ( D cdot 3 ) ( overline{2} ) |
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| 387 | The negative charge ( -q_{2} ) is fixed while positive charge ( q_{1} ) as well as the conducting sphere ‘S’ is free to move. If the system is released from rest (the total charge on ( mathrm{S} ) being zero. A. Both S and ( q_{1} ) move towards left B. ( q_{1} ) moves towards right while ( S ) moves towards left. C ( cdot q_{1} ) remains at rest, ( S ) moves towards left D. Both ( q_{1} ) and ( S ) remain at rest |
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| 388 | An electric dipole is placed at the centre of a sphere, choose the correct options: A. electric field is zero at every point on the surface B. flux is zero across the surface C. no circle is present in the sphere which is equipotentia D. none of the above |
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| 389 | In the given figure, the work done in taking the charge q from M to N is ( mathbf{A} cdot frac{2 k q Q}{a} ) B. ( frac{2 sqrt{2} k q Q}{a} ) c. ( frac{sqrt{2} k q Q}{a} ) D. zer |
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| 390 | Define electric potential due to a point charge and arrive at the expression for the electric potential at a point due to a point charge in its vicinity. | 12 |
| 391 | The equivalent capacitance between ( mathrm{P} ) and ( Q ) of the given figure is (the capacitance of each capacitor is1 ( mu F ) ): ( A cdot 2 mu F ) B. ( 0.5 mu F ) ( c cdot 5 mu F ) D. ( 0.2 mu F ) |
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| 392 | The electrostatic potential energy of two point charges, ( 1 mu C ) each, placed 1 meter apart in air is? ( begin{array}{l}text { A } cdot 9 times 10^{3} \ text { j }end{array} times 10^{times 10} ) В. ( 9 times 10^{9} ), |
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| 393 | Five identical conducting plates, 1.2,3,4 and 5 are fixed parallel plates equidistant from each other (see figure). A conductor connects plates 2 and 5 while another conductor joins 1 and 3. The junction of 1 and 3 and the plate 4 are connected to a source of constant emf ( V_{o} ). Find the effective capacitance of the system between the terminals of source where ( d ) is the distance between any two successive plates |
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| 394 | Four metallic plates are arranged as shown in the figure. If ( d ) is the distance between each plate then capacitance of the given system between points ( A ) and ( B ) is : ( (operatorname{given} boldsymbol{d}<<boldsymbol{A}) ) ( mathbf{A} cdot frac{epsilon_{0} A}{d} ) B. ( frac{2 epsilon_{0} A}{d} ) c. ( frac{3 epsilon_{0} A}{d} ) D. ( frac{4 epsilon_{0} A}{d} ) |
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| 395 | If two electric charges ( q ) and ( -2 q ) are placed at distance ( 6 a ) apart, then locus of point in the plane of charges, where electric potential is zero is: (Take charge ( q ) at origin and ( -2 q ) lies on positive ( x ) -axis A. ( x^{2}+y^{2}+4 a x-6 a^{2}=0 ) B . ( x^{2}+y^{2}+4 a x-12 a^{2}=0 ) c. ( x^{2}+y^{2}+2 a x-12 a^{2}=0 ) D. ( x^{2}+y^{2}-4 a x+12 a^{2}=0 ) |
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| 396 | Assertion A point charge ( q ) is placed in front of a solid conducting sphere. Electric field due to induced charges at the centre of sphere is zero. Reason Electric field at point inside the solid body of conductor is zero. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 397 | When dielectric medium of constant is filled between the plates of a charged parallel-plate condenser, then the energy stored becomes, as compared to its previous value, ( mathbf{A} cdot K^{-3} )times B. ( K^{-2} )times c. ( K^{-1} )times D. Ktimes |
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| 398 | If electric intensity ( vec{E} ) is along the ( X ) axis, then the equipotential surfaces are parallel to A. xor plane B. x0Z plane c. YOZ plane D. None of these |
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| 399 | A parallel-plate air condenser of plate area ( A ) and separation d is charged to potential ( V ) and then the battery is removed. Now a slab of dielectric constant ( k ) is introduced between the plates. If ( Q, E ) and ( W ) denote respectively the magnitude of charge on each plate, the electric field between the plates (after introduction of dielectric slab) and work done on the system in the process of introducing the slab, then This question has multiple correct options A ( cdot W=frac{varepsilon_{0} A V h^{2}}{2 d}(1-1 / k) ) ( ^{mathbf{B}} cdot Q=frac{varepsilon_{0} K A V}{d} ) ( ^{mathbf{C}} cdot Q=frac{varepsilon_{0} A V}{d} ) D. ( quad E=frac{V}{k d} ) |
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| 400 | A positive point charge q is carried from a point B to a point A in the electric field of a point charge ( +mathrm{Q} ) held at ( 0 . ) If the permittivity of free space is ( epsilon_{0} ) and ( 0 A=a ) and ( 0 mathrm{B}=mathrm{b}, ) the work done in the process is given by : A. ( frac{q Q}{4 pi epsilon_{0}}left(frac{1}{a}+frac{1}{b}right) ) в. ( frac{q Q}{4 pi epsilon_{0}}left(frac{1}{a}-frac{1}{b}right) ) c. ( frac{q Q}{4 pi epsilon_{0}}left(frac{1}{a^{2}}-frac{1}{b^{2}}right) ) D. ( frac{q Q}{4 pi epsilon_{0}}left(frac{1}{a^{2}}+frac{1}{b^{2}}right) ) |
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| 401 | A parallel plate capacitor is to be designed with a voltage rating ( 1 mathrm{kV} ) using a material of dielectric constant 3 and dielectric strength about ( mathbf{1 0}^{mathbf{7}} boldsymbol{V} boldsymbol{m}^{-1} . ) (Dielectric strength is the maximum electric field a material can tolerate without breakdown, i.e., without starting to conduct electricity through partial ionisation.) For safety, we should like the field never to exceed, say ( 10 % ) of the dielectric strength.What minimum area of the plates is required to have a capacitance of 50 pF ? |
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| 402 | The electric field due to the electric potential ( V=left(2 x^{2}-4 xright) ) is ( mathbf{A} cdot(4 x+4) hat{i} ) B. ( (4 x-4) hat{i} ) c. ( (-4 x+4) hat{i} ) D. ( (-4 x-4) hat{i} ) |
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| 403 | A uniform electric field of magnitude ( mathbf{1 0 0} V / boldsymbol{m} ) in space is directed along the line ( y=3+x . ) Find the electric potential difference between (1,3) and (3,1) A. ( 100 V ) в. ( 200 sqrt{2} V ) c. ( 200 V ) D. |
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| 404 | Find ( left|V_{B A}right| ) if ( 12 J ) of work has to be done against an electric field to take a charge of ( 10^{-2} C ) from ( a ) to ( b ) |
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| 405 | A point charge ( q ) is brought form infinity and is placed at the centre of a conducting neutral spherical shell of inner radius ( a ) and outer radius ( b, ) then work done by external agent is: ( A ) B. ( frac{k q^{2}}{2 b} ) c. ( frac{k q^{2}}{2 b}-frac{k q^{2}}{2 a} ) D. ( frac{k q^{2}}{2 a}-frac{k q^{2}}{2 b} ) |
12 |
| 406 | Two identical air filled parallel plate capacitors are charged to the same potential in the manner shown by closing the switch S. If now the switch is opened and the space between the plates is filled with a dielectric of relative permittivity ( varepsilon_{r}, ) then : A. The potential difference as well as charge on each capacitor goes up by a factor ( varepsilon_{r} ) B. The potential difference as well as charge on each capacitor goes down by a factor ( varepsilon_{r} ) c. The potential difference across A remains constant and the charge on B remains unchanged D. The potential difference across B remains constant while the charge on A remains unchanged |
12 |
| 407 | Two point charges ( 2 C ) and ( -1 C ) are placed at ( boldsymbol{x}=mathbf{0} ) and ( boldsymbol{x}=boldsymbol{6} ) respectively. The potential will be zero at points: A. ( x=2,-2 ) в. ( x=1,5 ) c. ( x=4,12 ) D. ( x=2,9 ) |
12 |
| 408 | Three charges ( 2 q,-q ) and ( -q ) are located at the vertices of an equilateral triangle. At the centre of the triangle: A. the field is zero but potential is non-zero B. the field is non-zero, but potential is zero c. both field and potential are zero D. both field and potential are non-zero |
12 |
| 409 | A capacitor of capacitance ( C ) is charged to a potential difference V from a cell and then disconnected from it. A charge +Q is now given to its positive plate. The potential difference across the capacitor is now: A. ( V ) B. ( V+frac{Q}{C} ) ( c cdot V+frac{Q}{2 C} ) D. ( V-frac{Q}{C}, ) if ( V<C V ) |
12 |
| 410 | Write the definition of electric potential. Calculate the electric potential due to a point charge ( Q ) at a distance ( r ) from it. Draw a graph between electric potential Vand distance r for a point charge ( Q ) | 12 |
| 411 | A spark is produced between two insulated surfaces maintained at a potential difference of ( 5 times 10^{6} V . ) If the energy output is ( 10^{-5} J ), the charge transferred during the spark is : A ( cdot 5 times 10^{11} C ) В. ( 5 times 10^{-11} C ) C ( cdot 2 times 10^{12} C ) D. ( 2 times 10^{-12} C ) |
12 |
| 412 | A hexagon of side ( 8 mathrm{cm} ) has a charge 4 ( mu C ) at each of its vertices. The potentia at the centre of the hexagon is A ( cdot 2.7 times 10^{6} mathrm{v} ) B ( .7 .2 times 10^{11} mathrm{v} ) C ( .2 .5 times 10^{12} mathrm{v} ) D. ( 3.4 times 10^{4} mathrm{v} ) |
12 |
| 413 | A parallel plate capacitor of plate area ( A ) and plate separation ( d ) is charged to potential difference ( V ) and then the battery is disconnected. A slab of dielectric constant ( k ) is then inserted between the plates of the capacitor so as to fill the space between the plates. If ( Q, E ) and ( W ) denote respectively, the magnitude of charge on each plate, the electric field between the plates (after the slab is inserted) and the work done on the system, in question, in the process of inserting the slab, then: This question has multiple correct options A ( cdot Q=frac{epsilon_{0} A V}{d} ) в. ( Q=frac{epsilon_{0} k A V}{d} ) c. ( quad E=frac{V}{k d} ) D. ( W=-frac{epsilon_{0} A V^{2}}{2 d}left(1-frac{1}{k}right) ) |
12 |
| 414 | An infinitely long straight conductor is uniformly charged with charge density ( lambda ) per meter. The work done to bring a charge ( q_{0} ) at perpendicular distance ( b ) to ( a ) perpendicular distance ( a(a<b) ) from the conductor is : A. zero в. ( frac{q_{0} lambda}{2 pi_{0}} ) c. ( frac{q_{0} lambda}{2 pi varepsilon_{0}} log _{0}left(frac{b}{a}right) ) D. ( frac{q_{0} lambda}{2 pi varepsilon_{0}} log _{0}left(frac{a}{b}right) ) |
12 |
| 415 | You are given an arrangement of three point charges ( q, 2 q ) and ( x q ) separated by equal finite distances so that electric potential energy of the system is zero. then the values of ( x ) is: ( A cdot-2 / 3 ) B. -1/3 ( c cdot 2 / 3 ) D. 3/2 |
12 |
| 416 | Two point charges, each of charge ( q, ) are placed at a separation of ( 2 a ). The electric potential at their midpoint will be : A. zero в. ( frac{q}{2 pi varepsilon_{0} a} ) c. ( frac{q}{8 pi varepsilon_{0} a} ) D. ( frac{q}{2 pi varepsilon_{0} a^{2}} ) |
12 |
| 417 | Q Type your question now-famous oil-drop experiment. In that experiment, tiny oil drops were sprayed into a uniform electric field between a horizontal pair of oppositely charged plates.The drops were observed with a magnifying eyepiece, and the electric field was adjusted so that the upward force on some negatively charged oil drops was just sufficient to balance the downward force of gravity. That is, when suspended, upward force qE just equaled mg. Millikan accurately measured the charges on many oil drops and found the values to be whole number multiples of ( 1.6 times 10^{-19} C ) the charge of the electron. For this, he won the Nobel prize. If a drop of mass ( 1.08 times ) ( 10^{-14} k g ) remains stationary in an electric field of ( 1.68 times 10^{5} N C^{-1} ), then the charge of this drop is : A. ( 6.40 times 10^{-19} mathrm{C} ) B . ( 3.2 times 10^{-19} C ) c. ( 1.6 times 10^{-19} C ) D. ( 4.8 times 10^{-19} mathrm{C} ) |
12 |
| 418 | Two equal charges ( q ) are placed at a distance ( 2 a ) and a third charge ( -2 q ) is placed at the midpoint. The potential energy of the system is A ( cdot frac{9 q^{2}}{8 pi epsilon_{0} a} ) В. ( frac{q^{2}}{8 pi epsilon_{0} a} ) c. ( frac{-7 q^{2}}{8 pi epsilon_{0} a} ) D. ( frac{6 q^{2}}{8 pi epsilon_{0} a} ) |
12 |
| 419 | The potential difference between the two plates of a parallel plate capacitor is constant. When air between the plates is replaced by dielectric material, the electric field intensity: A. Decreases B. Remains unchanged c. Becomes zero D. Increases |
12 |
| 420 | A right isosceles triangle of side ( a ) has charges ( boldsymbol{q},+boldsymbol{3} boldsymbol{q} ) and ( -boldsymbol{q} ) arranged on its vertices as shown in the figure. What is the electric potential at point ( boldsymbol{P} ) midway between the line connecting the ( +q ) and ( -q ) charges? A ( cdot frac{3 q}{r epsilon_{6} a} ) В. ( frac{3 q}{sqrt{2} pi epsilon a a} ) c. ( frac{q}{pi epsilon_{a} a} ) D. ( frac{3 q}{2 sqrt{2} pi epsilon_{0} a} ) |
12 |
| 421 | The figure shows the field lines of a positive point charge. The work done by the field in moving a small positive charge from ( Q ) to ( P ) is: A. zero B. Positive c. Negative D. Data insufficient |
12 |
| 422 | If a charge is shifted from a high potential region to low potential region, the electrical potential energy A. Increses B. Decreses c. May increase or decrease D. Remains constant |
12 |
| 423 | The two capacitors ( 2 mu F ) and ( 6 mu F ) are put in series, the effective capacity of the system is ( mu boldsymbol{F} ) is: ( A cdot 8 mu F ) в. ( 2 mu F ) c. ( 3 / 2 mu F ) D. ( 2 / 3 mu F ) |
12 |
| 424 | ( A . ) another positively charged particle of mass ( m ) and charge ( +q ) is projected from a point ( B ) with velocity ( u ) as shown in figure. The point ( B ) is at the lage distance from ( A ) and at distance ( d ) from the line ( A C . ) The initial velocity is parallel to the line ( A C . ) The point ( C ) is at very large distance from ( A ). The minimum distance (in meter) of ( +boldsymbol{q} ) from ( +Q ) during the motion is ( d(1+ ) ( sqrt{A}) . ) Find the value of ( A ) (Take ( boldsymbol{Q} boldsymbol{q}=boldsymbol{4} boldsymbol{pi} varepsilon_{0} boldsymbol{m} boldsymbol{u}^{2} boldsymbol{d} ) and ( boldsymbol{d}=(sqrt{mathbf{2}}- ) 1) meter) A . 3 B. 2 ( c cdot 4 ) ( D ) |
12 |
| 425 | A parallel-plate capacitor with plate area ( A ) and separation between the plates ( d, ) is charged by a constant current ( i . ) Consider a plane surface of area ( A / 2 ) parallel to the plates and drawn symmetrically between the plates. Find the displacement current through this area. |
12 |
| 426 | Assertion Dielectric material (dielectric for short) is an electrical insulator that can be polarized by an applied electric field. Reason Electric field attracts the polarised or |
12 |
| 427 | A number of capacitors, each of equal capacitance ( C, ) are arranged as shown in the figure. The equivalent capacitance between ( A ) and ( B ) is : A ( cdot n^{2} C ) B. ( (2 n+1) C ) c. ( frac{(n-1) n}{2} C ) D. ( frac{(n+1) n}{2} C ) |
12 |
| 428 | Four electric charges ( +boldsymbol{q},+boldsymbol{q},-boldsymbol{q} ) and ( -q ) are placed at the corners of a square of side ( 2 L ) (see figure). The electric potential at point ( A, ) midway between the two charges ( +boldsymbol{q} ) and ( +boldsymbol{q} ), is A ( cdot frac{1}{4 pi epsilon_{0}} frac{2 q}{L}(1+sqrt{5}) ) в. ( frac{1}{4 pi epsilon_{0}} frac{2 q}{L}left(1+frac{1}{sqrt{5}}right) ) c. ( frac{1}{4 pi epsilon_{0}} frac{2 q}{L}left(1-frac{1}{sqrt{5}}right) ) D. zero |
12 |
| 429 | ( boldsymbol{n} ) small drops of small size are charged to ( V ) volt each. If they collapse to form a single large drop, then its potential will be ( mathbf{A} cdot(V / n) ) в. ( V n ) ( mathbf{c} cdot V n^{2 / 3} ) D. None of these |
12 |
| 430 | Five capacitors of ( 10 mu F ) capacity each are connected to a d.c. potential of 100 volts as shown in the adjoining figure. The equivalent low capacitance between the points ( A ) and ( B ) will be equal to: ( mathbf{A} cdot 40 mu F ) B. ( 20 mu F ) c. ( 30 mu F ) ( mathbf{D} cdot 10 mu F ) |
12 |
| 431 | Figure shows some equipotential lines distributed in space. A charged object is moved from point ( A ) to point ( B ) A. The work done in figure (i) is the greatest. B. The work done in figure (ii) is the least. C. The work done is the same in figure (i), (ii) and (iii) D. The work done is the same in figure (iii) is greater than figure (ii) but equal to that in figure (i). |
12 |
| 432 | The electric potential due to charges ( 2 q ) and ( -3 q, ) fixed at points ( (4 m, 0,0) ) and ( (9 m, 0,0) ) respectively, is zero on: A ( cdot ) a spherical surface ( x^{2}+y^{2}+z^{2}=36 ) B. a parabola ( y^{2}=36 z ) c. an ellipsoidal ( frac{x^{2}}{16}+frac{y^{2}}{81}+z^{2}=1 ) D. a spherical surface ( (x-4)^{2}+y^{2}+z^{2}=81 ) |
12 |
| 433 | Three charges ( +boldsymbol{q},+boldsymbol{q} ) and ( -boldsymbol{q} ) are situated in ( x ) -y plane at the point ( (0, a),(0,0),(0,-a) . ) Then, the electric potential at a point in first quadrant whose position vector makes an angle ( theta ) with the ( y ) -axis and at a distance ( r(r> ) ( >a) ) from the origin is : A ( cdot frac{q a cos theta}{2 pi varepsilon_{0} r^{2}} ) в. ( frac{q}{4 pi varepsilon_{0} r}left(1+frac{2 a cos theta}{r}right) ) c. ( frac{q}{4 pi varepsilon_{0} r} ) D. ( frac{q}{4 pi varepsilon_{0} r}left(1-frac{2 a cos theta}{r}right) ) |
12 |
| 434 | Which of the following is not a unit for electric potential? A. volt B. Joule/coulomb c. Erg/stat coulomb D. None of these |
12 |
| 435 | In an electric field of a point charge ( boldsymbol{q}, ) a certain charge is carried from point ( boldsymbol{A} ) to ( B, C, D, E . ) Then, the work done ( A ). is least along path ( A B ) C. is zero along all paths D. is least along path ( A E ) |
12 |
| 436 | A sliding rod ( A B ) of resistance ( R ) is shown in the figure. Here magnetic field ( B ) is constant and is Out of the paper. Parallel wires have no resistance and the rod is moving with Constant velocity v. The current in the sliding rod AB in the function of ( t, ) when switch ( mathrm{S} ) is closed at time ( mathrm{t}=0 ) is ( ^{A} cdotleft(frac{v B d}{R}right) e^{-t / c} ) ( ^{mathbf{B}} cdotleft(frac{v B d}{R}right) e^{-t / R C} ) ( ^{mathrm{c}} cdotleft(frac{v B d}{R}right) e^{R t C} ) D. ( left(frac{v B d}{R}right) e^{t / R C} ) |
12 |
| 437 | The plate separation in a parallel plate capacitor is ( d ) and plate area is ( A ). If it is charged to ( V ) volts then calculate the work done in increasing the plate separation to ( 2 d ) then | 12 |
| 438 | In a uniform electric field, equipotential surfaces must: This question has multiple correct options A. be plane surfaces B. be normal to the direction of the field C. be placed such that surfaces having equal differences in potential are separated by equal distances D. have decreasing potentials in the direction of the field |
12 |
| 439 | The equivalent capacitance of capacitors ( 6 mu F ) and ( 3 mu F ) connected in series is ( mathbf{A} cdot 3 mu f ) B. ( 2 mu f ) c. ( 4 mu f ) D. ( 6 mu f ) |
12 |
| 440 | Four large parallel identical conducting plates of area A are arranged as shown in fig. The charges on each plate are given in the figure and the separation between the plates is d(d is very small). The surfaces of the plates are numbered (1), (2), (1) |
12 |
| 441 | A parallel plate air condenser has capacity of ( 20 mu F ). If the distance between two plates is doubled, then new capacity will be A ( .5 mu F ) B. ( 10 mu F ) ( mathbf{c} cdot 15 mu F ) D. ( 20 mu F ) |
12 |
| 442 | Define electric potential and write down its dimension. | 12 |
| 443 | Assertion A polarised atom can be approximated as a dipole. Reason Electric field induces the charge separation in the atom. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 444 | Which of the following statements is correct? A. The balls will execute simple harmonic motion between the two plates B. The balls will bounce back to the bottom plate carrying the same charge they went up with C. The balls will stick to the top plate an remain there D. The balls will bounce back to the bottom plate carrying the opposite charge they went up with |
12 |
| 445 | A conducting rod of resistance is moving with constant velocity ( v_{1} ) then the force required to keep rod moving is ( frac{v B^{2} l^{2}}{R} ) в. ( frac{2 v B^{2} l^{2}}{R+r} ) c. ( frac{v B^{2} l^{2}}{R+r} ) D. zer |
12 |
| 446 | Identical charges q each are placed at the eight corners of a cube of side ( b ) Find the electrostatic potential energy of a charge ( +q ) placed at the center of the cube |
12 |
| 447 | A method for charging a conductor without bringing a charged body in contact with it is called: A. Magnetization B. Electrification c. Electrostatic induction D. Electromagnetic induction |
12 |
| 448 | Potential difference is also called A. voltage B. Biot c. coulomb D. Ampere |
12 |
| 449 | Surface charge density of the plate is equal to ( mathbf{A} cdot 8.85 times 10^{-10} mathrm{C} / mathrm{m}^{2} ) B . ( -8.85 times 10^{-10} C / m^{2} ) C ( cdot 17.7 times 10^{-10} mathrm{C} / mathrm{m}^{2} ) D. ( -17.7 times 10^{-10} C / m^{2} ) |
12 |
| 450 | A metal plate of thickness half the separation between the capacitor plates of capacitance ( C ) is inserted. The new capacitance is: A . B. ( frac{c}{2} ) c. zero D. 2C |
12 |
| 451 | Prove that the electric potential at a point in broad side on position due to an electric dipole is zero. | 12 |
| 452 | A parallel plate capacitor is given a definite potential difference. Keeping the potential difference same, a slab of thickness ( 3 mathrm{mm} ) is placed between the plates. To do this, the distance between the plates is increased by ( 2.4 mathrm{mm} ) Calculate the dielectric constant of the slab. ( (mathbf{a}) ) (b) ( A cdot 10 ) В. 15 ( c .5 ) ( D ) |
12 |
| 453 | Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of ( 30^{0} ) with each other. When suspended in a liquid of density ( 0.8 mathrm{gcm}^{-3}, ) the angle remains the same. If density of the material of the sphere is ( 1.6 mathrm{gcm}^{-3} ), the dielectric constant of the liquid is : ( A cdot 4 ) B. 3 ( c cdot 2 ) ( D ) |
12 |
| 454 | The capacity of a parallel plate capacitor with no dielectric substance but with a separation of ( 0.4 mathrm{cm} ) is ( 2 mu F ) If the separation is reduced to half and it is filled with a dielectric substance of value ( 2.8, ) then the final capacity of the capacitor is A ( .11 .2 mu F ) в. ( 15.6 mu F ) c. ( 19.2 mu F ) D. 22.4 ( mu F ) |
12 |
| 455 | coordinates as ( boldsymbol{v}=left(boldsymbol{x}^{2}-boldsymbol{y}^{2}right) ) Corresponding electric field lines in ( x-y ) plane as shown in the figure are ( A ) B. ( mathbf{c} ) D. |
12 |
| 456 | Choose the wrong statement about equipotential surfaces. A. It is a surface over which the potential is constant B. The electric field is parallel to the equipotential surface C. The electric field is perpendicular to the equipotential surface D. The electric field is in the direction of steepest decrease of potential E. They are concentric spheres for a point charge |
12 |
| 457 | Capacity of a parallel plate condenser is ( 10 mu F ) when the distance between its plates is ( 8 mathrm{cm} ). If the distance between the plates is reduced to ( 4 mathrm{cm} ), its capacity will be: A. ( 10 mu F ) B. ( 15 mu F ) c. ( 20 mu F ) D. ( 40 mu F ) |
12 |
| 458 | A capacitor has a capacitance of 27.0 microfarads If we triple the area of the plates of the capacitance and cut the distance between the plates to ( 1 / 3 ) of its original value, what is the new capacitance of the capacitor? A. 243 microfarads B. 9.0 microfarads c. 3.0 microfarads D. 81.0 microfarads E. 27.0 microfarads |
12 |
| 459 | Three charges ( Q, q,-q ) are placed at the vertices of an equilateral triangle. If the net electric potential energy of the system is ( 0, ) then ( Q ) is ( A cdot-q ) B. ( q ) ( c cdot 0 ) D. None of the above |
12 |
| 460 | A charge ( +q ) is fixed at each of the points ( boldsymbol{x}=boldsymbol{x}_{0}, boldsymbol{x}=mathbf{3} boldsymbol{x}_{0}, boldsymbol{x}=mathbf{5} boldsymbol{x}_{0}, dots ) upto ( infty ) on ( mathrm{X} ) -axis and charge -q is fixed on each of the points ( boldsymbol{x}=mathbf{2} boldsymbol{x}_{0}, boldsymbol{x}= ) ( mathbf{4} boldsymbol{x}_{0}, boldsymbol{x}=boldsymbol{6} boldsymbol{x}_{0}, ldots boldsymbol{u} boldsymbol{p} boldsymbol{a} ) positive constant. Take the potential at a point due to a charge ( Q ) at a distance ( r ) from it to be ( frac{Q}{4 pi epsilon_{0} r} . ) Then the potentia at the origin due to above system of charges will be : A . zero в. ( frac{q}{8 pi epsilon_{0} x_{0} log _{e} 2} ) c. inifinty D. ( frac{q log _{e} 2}{4 pi epsilon_{6} x_{0}} ) |
12 |
| 461 | A point charge ( q ) is rotated along a circle in the electric field generated by another point charge ( Q ). The work done by the electric field on the rotating charge in one complete revolution is A . zero B. positive c. negative D. zero if the charge ( Q ) is at the center and nonzero otherwise |
12 |
| 462 | The current through the ammeter shown in the figure is ( 1 A ). If each of the 4 resistor is replaced by 2 resistor, the current in the circuit will become ( A cdot(a) frac{10}{9} A ) ( mathbf{B} cdot(mathbf{b}) frac{5}{4} A ) ( mathbf{c} cdot(mathrm{c}) frac{9}{8} A ) ( mathbf{D} cdot(mathrm{d}) frac{5}{8} A ) |
12 |
| 463 | Two capacitors of capacitance ( C ) are connected in series. If one of them is filled with a substance of dielectric constant ( K, ) what is the effective capacitance? ( ^{A} cdot frac{K C}{(1+k)} ) в. ( C(K+1) ) c. ( frac{2 K C}{(1+k)} ) D. None of these |
12 |
| 464 | A parallel-plate air capacitor of capacitance ( C_{0} ) is connected to a cell of emf ( V ) and then disconnected from it. ( A ) dielectric constant ( K, ) which canjust fill the air gap of capacitor, is now inserted in it. Which of the following is incorrect? A. The potential difference between the plates decreases ( K ) times B. The energy stored in the capacitor decreases ( K ) times. C ‘ the change in energy is ( frac{1}{2} C_{0} varepsilon^{2}(K-1) ) D. The change in energy is ( frac{1}{2} C_{0} varepsilon^{2}left(1-frac{1}{k}right) ) |
12 |
| 465 | A parallel plate capacitor with plates separated by air acquires ( 1 mu mathrm{C} ) of charge when connected to a battery of ( 500 mathrm{V} ). The plates still connected to the battery are then immersed in benzene ( (k=2.25) ) Then a charge flows from the battery is : A. ( 1.25 mu ) С B. ( 2.28 mu ) С c. ( 1 / 4 mu ) с D. ( 4.56 mu ) С |
12 |
| 466 | Surface charge density of a sphare of a radius ( 10 mathrm{cm} ) is ( 8.85 times 10^{-8} c / m^{2} ) Potential at the centre of the sphare is A . ( 1000 V ) B. ( 885 V ) ( c cdot 10^{-3} ) D. ( 442.5 V ) |
12 |
| 467 | Two capacitors of capacities ( 3 mu mathrm{F} ) and ( 6 mu F ) are connected in series and connected to 120V. The potential differences across ( 3 mu ) ( mathrm{F} ) is ( V_{0} ) and the charge here is ( q_{0} . ) We have : A) ( q_{0}=40 mu C ) B) ( V_{0}=60 V ) ( left.mathrm{C}) V_{0}=80 mathrm{V} quad mathrm{D}right) q_{0}=240 mu C ) ( A cdot A, C ) are correct B. A, B are correct c. ( B, ) D are correct D. ( c, ) D are correct |
12 |
| 468 | Electric potential is the force experienced by a unit positive charge placed at a point A. True B. False |
12 |
| 469 | Deduce an expression for the effective capacitance of capacitors of ( C_{1}, C_{2} ) and ( C_{3} ) connected in series |
12 |
| 470 | There are two concentric spherical shells of radii ( r ) and ( 2 r . ) Initially a charge ( Q ) is given to the inner shell and both the switches are open. If switch ( S_{1} ) is closed and then opened, charge on the outer shell will be ( A cdot Q ) в. ( frac{Q}{2} ) c. ( -Q ) D. ( frac{-Q}{2} ) |
12 |
| 471 | Two positive charges ( Q ) and ( 4 Q ) are placed at points ( A ) and ( B ) respectively where ( mathrm{B} ) is at a distance ‘d’ units to the right of A. The total electric potential due to these charges in minimum at ( mathrm{P} ) on the line through ( A ) and ( B ), What is (are) the distance(s) of P from A? A. ( d ) ( frac{d}{3} ) units to the right of ( A ) B. ( frac{d}{3} ) units to the left of c. ( frac{d}{5} ) units to the right of D. d units to the left of A |
12 |
| 472 | Explain the concept of a parallel plate capacitor. State its any ‘two’ applications. | 12 |
| 473 | In Milikan’s oil drop experiment, an oil drop of radius ( r ) and charge ( q ) is held in equilibrium between the plates of a charged parallel plate capacitor when the potential difference is ( V . ) To keep a drop of radius ( 2 r ) and with a charge ( 2 q ) in equilibrium between the plates the potential difference ( boldsymbol{V} ) required is : A. ( V ) B. ( 2 V ) ( c .4 V ) D. ( 8 V ) |
12 |
| 474 | Calculate the work done by electric field when a point charge q is moved from point ( mathrm{B} ) to ( mathrm{A} ) along the curved path. Given that electric field is created by the stationary charge ( mathrm{Q} ) and ( V_{A}= ) ( 200 V, V_{B}=100 V, q=0.05 C, ) length of line segment ( A B=10 mathrm{cm}, ) length of curved path ( =20 mathrm{cm} ) A . O B. 5 c. 10 D. 15 J E. 20 |
12 |
| 475 | A charge of ( 10 mathrm{C} ) is brought from infinity to a point near a charged body and in this process, 200 J of work is done Calculate the electric potential at that point near the charged body A . ( 20 mathrm{v} ) B. ( 10 mathrm{v} ) ( c .5 v ) D. 15 v |
12 |
| 476 | The slight separation of charge, or polarization A. reduces the electric field within the dielectric. B. increases the electric field within the dielectric. C. doesn’t effect the electric field within the dielectric. D. none of the above |
12 |
| 477 | A capacitor has a capacitance of ( 7.28 mu F . ) What amount of charge in ( (mu C ) must be placed on the plates to make the potential difference between its plates equal to ( 25.0 mathrm{V} ? ) |
12 |
| 478 | A charge of ( 5 mu mathrm{C} ) is placed at the center of a square ( A B C D ) of side ( 10 mathrm{cm} . ) Find the work done (in ( mu ) ) in moving a charge of ( 1 mu C ) from ( A ) to ( B ) |
12 |
| 479 | Consider two concentric spherical metal shells of radii ( r_{1} ) and ( r_{2}left(r_{2}>r_{1}right) ) If the outer shell has a charge q and the inner one is grounded, the charge on the inner shell is : A ( cdot frac{-r_{2}}{r_{1}} q ) B. Zero c. ( frac{-r_{1}}{r_{2}} q ) D. ( -q ) |
12 |
| 480 | Equipotential lines are shown, what is the approximate voltage at point ( P ) in the diagram? A . 12 ( v ) B. ( 8.0 mathrm{v} ) ( c cdot 8.5 v ) D. ( 6.0 mathrm{v} ) |
12 |
| 481 | Electric field intensity is the strength of an electric field at any point which is the electric force per unit charge experienced by a test charge placed at that point. A. Greater than B. Lesser than c. Equal to D. None |
12 |
| 482 | The electric potential at a point in free space due to a charge ( Q ) coulomb is ( Q times 10^{11} V . ) The electric field at that point is A ( cdot 12 pi varepsilon_{0} Q times 10^{22} V m^{-1} ) B . ( 4 pi varepsilon_{0} Q times 10^{22} V m^{-1} ) C ( .12 pi varepsilon_{0} Q times 10^{20} mathrm{Vm}^{-1} ) D. ( 4 pi varepsilon_{0} Q times 10^{20} V m^{-1} ) |
12 |
| 483 | A parallel plate condenser with oil between the plates (dielectric constant of oil ( K=2 ) ) has a capacitance ( C . ) If the oil is removed, then capacitance of the capacitor becomes: A ( cdot sqrt{2} C ) в. ( 2 C ) c. ( frac{C}{sqrt{2}} ) D. ( frac{c}{2} ) |
12 |
| 484 | Which of the following can be used as dielectric? This question has multiple correct options A. Mineral oil B. Electrets C. Sulfur hexafluoride D. None of the above |
12 |
| 485 | The capacity of a parallel plate condenser is ( C . ) Its capacity when the separation between the plates is halved will be : A . ( 4 C ) в. ( 2 C ) c. ( frac{c}{2} ) D. ( frac{C}{4} ) |
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| 486 | If an earthed plate is brought near a positively charged plate, the potential and capacity of charged plate respectively: A. increases, decreases B. decreases, increases c. decreases, decreases D. increases, increases |
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| 487 | (a) Obtain a relation for equivalent capacitance of the series combination of capacitors. Draw a circuit diagram (b) 10 capacitors each of capacity ( 10 mu F ) are joined first in series and then in parallel. Write the value of product of equivalent capacitances. (c) What will be the value of capacitance of a ( 4 mu F ) capacitor if a dielectric of dielectric constant 2 is inserted fully between the plates of parallel plate capacitor. |
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| 488 | Draw a plot showing the variation of (i) electric field ( (boldsymbol{E}) ) and (ii) electric potential ( (V) ) with distance ( r ) due to a point charge ( Q ) |
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| 489 | Find the charge appearing on capacitor of capacitance ( 4 mu F ) A ( .32 mu C C ) B. ( 96 mu C ) c. ( 12 mu C ) |
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| 490 | In an hydrogen atom, the electron revolves around the nucleus in an orbit of radius ( 0.53 times 10^{-10} m . ) Then the electrical potential produced by the nucleus at the position of the electron is |
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| 491 | Find out the points on the line joining two charges ( +boldsymbol{q} ) and ( boldsymbol{3} boldsymbol{q} ) (kept at a distance of ( 1.0 m ) in that order), where electric potential is zero. This question has multiple correct options A. ( 0.5 m ) to the left of ( q ) B. ( 0.5 m ) to the right of ( q ) c. ( 0.25 m ) to the right of ( q ) D. ( 0.75 m ) to the right of ( q ) |
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| 492 | When no current is passed through a conductor A. the free electrons do not move B. the average speed of a free electrons over a large speed of time is zero C. the average velocity of a free electron over a large period of time is zero D. the average of the velocities of all the free electrons at an instant is zero |
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| 493 | A spherical metal shell A of radius ( boldsymbol{R}_{boldsymbol{A}} ) and a solid metal sphere ( B ) of radius ( R_{B}left(Q_{B} ) C ( frac{sigma_{A}}{sigma_{B}}=frac{R_{B}}{R_{A}} ) D. ( E_{A}^{text {onsurface }}<E_{B}^{text {onsurface }} ) |
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| 494 | A particle with a charge of 3 coulombs is taken from a point at a potential of 50 V to another point at a potential of ( 120 mathrm{V} ) Calculate the work done. A . 23.33 J B. 2.4 J c. 210 D. 40 J |
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| 495 | The figure shows a capacitor having three layers of equal thickness and same area as that of plate. the layer first is vaccum, second is conductor and third is dielectric of dielectric constant ( K . ) The ratio of energy stored in region three to total energy stored in capacitor three is : A ( cdot frac{1}{K+1} ) в. ( frac{3}{K+1} ) ( c cdot frac{4}{K+3} ) D. ( frac{4}{K+1} ) |
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| 496 | Which of the following is/are polar dielectric molecules? This question has multiple correct options A ( . N H_{3} ) B. Benzene c. Methane D. ( H C L ) |
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| 497 | The kinetic energy of an electron, which is accelerated in the potential difference of ( 100 V, ) is A . ( 1.6 times 10^{-10} mathrm{J} ) в. ( 1.6 times 10^{8} mathrm{J} ) c. ( 1.6 times 10^{-17} J ) D. ( 1.6 times 10^{-18} mathrm{J} ) |
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| 498 | The plates of a parallel plate capacitor have an area of ( 90 mathrm{cm}^{2} ) each and are separated by ( 2.5 m m . ) The capacitor is charged by a 400 volt supply. How much electrostatic energy is stored by the capacitor? A ( .2 .55 times 10^{-6} J ) В. ( 1.55 times 10^{-6} J ) c. ( 8.15 times 10^{-6} J ) D. ( 5.5 times 10^{-6} J ) |
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| 499 | Two equal point charges are fixed at ( x= ) ( -a ) and ( x=+a ) on the ( x ) -axis. Another point charge ( Q ) is placed at the origin. The change in the electrical potential energy of ( mathrm{Q}, ) when it is displaced by a smal distance ( x ) along the ( x ) -axis, is approximately proportional to : ( A cdot x ) B . ( x^{2} ) c. ( x^{3} ) D. ( 1 / x ) |
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| 500 | A parallel plate capacitor has 91 plates all are identical and arranged with same spacing between them. If the capacitance between adjacent plates is ( 3 p F . ) What will be the resultant capacitance? A . 273 pF B . ( 30 p F ) c. ( 94 p F ) D. 270 ( p F ) |
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| 501 | A conductor A with a cavity as shown in the figure is given a charge ( Q . ) Find net charge appear on the inner surface of the cavity. ( mathbf{A} cdot+Q ) B. – ( Q ) c. ( -Q / 2 ) D. zero |
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| 502 | A spherical volume contains a uniformly distributed charge density of ( 2 times 10^{-4} mathrm{Cm}^{-3} . ) The electric field at a distance of ( 4 mathrm{cm} ) from the centre is : A . ( 3 times 10^{5} ) B . ( 3 times 10^{4} ) ( c cdot 2 times 10^{5} ) D. ( 3 times 10^{6} ) |
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| 503 | Two point charges ( 2 q ) and ( 8 q ) are placed at a distance r apart. Where should a third charge -q be placed between them so that the electrical potential energy of the system is a minimum. A. At a distance of r/3 from 2 q. B. At a distance of 2 r/3 from 2 2 c. At a distance of r/16 from 2q. D. There is no such position |
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| 504 | Three mass points each of mass ( m ) are placed at the vertices of an equilateral triangle of side ( 1 . ) What is the gravitational potential at the centroid of the triangle. |
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| 505 | What is the work done in moving a charge of ( 50 n C ) between two points on an equipotential surface? |
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| 506 | Suppose that you are in a cave deep within the earth. Are you safe from thunder and lightning? Justify your answer |
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| 507 | An infinite number of charges, each equal to q, are placed along the x-axis at ( x=1, x=2, x=4, x=8 ) and so on What is the potential at ( x=0 ) due to this set of charges? |
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| 508 | Two identical condensers M and N are connected in series with a battery. The space between the plates of M is completely filled with a dielectric medium of dielectric constant 8 and a copper plate of thickness ( frac{d}{2} ) is introduced between the plates of ( mathrm{N}(d ) is the distance between the plates). Then potential differences across ( mathrm{M} ) and ( mathrm{N} ) are, respectively, in the ratio: ( mathbf{A} cdot 1: 4 ) B . 4: 1 ( mathbf{c} cdot 3: 8 ) D. 1: 6 |
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| 509 | The capacitance of a capacitor is ( 10 F ) The potential difference on it is ( 50 V ). If the distance between its plate is halved, What will be the potential difference now? ( mathbf{A} cdot 100 V ) в. ( 50 V ) ( c .25 V ) D. ( 75 V ) |
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| 510 | Across the surface of a charged conductor, the electric: This question has multiple correct options |
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| 511 | Two electric charges ( q ) and ( -2 q ) are placed at a distance 3a apart. The locus of points in the plane of the charges where the field potential is zero is: A. straight line B. circle c. ellipse D. hyperbola |
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| 512 | A thin metallic spherical shell contains a charge ( Q ) on its surface. A point charge ( q_{1} ) is placed at the center of the shell, and another charge ( q_{2} ) is placed outside the shell. All the three charges are positive. Then the force on charge ( boldsymbol{q}_{1} ) is : A. toward right B. toward left c. zero of these |
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| 513 | When a dielectric slab is introduced between the two plates of condenser then its capacity A. remains constant B. increases c. decreases D. may increase or decrease depending on the material of dielectric slab |
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| 514 | Why are equipotential surfaces perpendicular to field lines? | 12 |
| 515 | Charges ( 5 mu mathrm{C} ) and ( 10 mu mathrm{C} ) are placed ( 1 mathrm{m} ) a part. Workdone to bring these charges at a distance ( 0.5 mathrm{m} ) from each other is ( left(k=9 times 10^{9} S Iright) ) ( mathbf{A} cdot 9 times 10^{4} J ) B . ( 18 times 10^{4} J ) c. ( 45 times 10^{2} J ) D. ( 9 times 10^{-1} J ) |
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| 516 | An infinite sheet carrying a uniform surface charge density ( sigma ) lies on the ( x y- ) plane. The work done to carry a charge ( q ) from the point ( vec{A}=a(hat{i}+2 j+3 hat{k}) ) to point ( vec{B}=a(hat{i}-2 hat{j}+6 hat{k}) ) (where a is constant with the dimension of length and ( varepsilon_{0} ) is the permittivity of free space) is : A. ( frac{3 sigma a q}{2 varepsilon_{0}} ) В ( cdot frac{2 sigma a q}{varepsilon_{0}} ) c. ( frac{5 sigma a q}{2 varepsilon_{0}} ) D. ( frac{3 sigma a q}{varepsilon_{0}} ) |
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| 517 | Potential difference between two points is 60 V. How much work will done on bringing charge of ( 3 times 10^{-5} ) Coulomb from one point to another point. |
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| 518 | Determine the electrostatic potential energy of a system consisting of two charges ( 7 mu C ) and ( -2 mu C ) (and with no external field) placed at ( (-9 c m .0 .0) ) and ( (9 c m, 0.0) ) respectively. |
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| 519 | A lamp is connected in series with a capacitor and an AC source. What happens if the capacity of the capacitor is reduced? A. The lamp shines more brightly B. The lamp shines less brigthly C. There is no change in the brightness of the lamp D. Brightness may increase or decrease depending on the frequency of the ( A C ) |
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| 520 | Three charges each ( 20 mu C ) are placed at the corners of an equilateral triangle of side of ( 0.4 m . ) The potential energy of the system is : ( mathbf{A} cdot 18 times 10^{-6} J ) B. ( 9 J ) c. ( 9 times 10^{-6} J ) D. 27J |
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| 521 | The parallel plate capacitor on the left ( C L ) has a separation distance of ( 1 mathrm{cm} ) and the sides of the square plate are each ( 0.5 m . ) While the smaller paralle plate capacitor on the right ( C R ) has a separation distance of ( 0.2 mathrm{cm} ) and each side of the square plate is ( 0.1 m ) in length. Determine the ratio of capacitance ( boldsymbol{C} boldsymbol{L}: boldsymbol{C} boldsymbol{R} ) A . 1: B. 5: ( c .1: 5 ) ( D .3 ) |
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| 522 | At the corners of an equilateral triangle of side a ( (1 text { metre }), ) three point charges are placed (each of ( 0.1 C ) ). If this system is supplied energy at the rate of 1 kw, then calculate the time required to move one of the mid-point of the line joining the other two. A . ( 50 h ) B. ( 60 h ) ( mathbf{c} cdot 48 h ) ( mathbf{D} cdot 54 h ) |
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| 523 | The equi-potential surface in the region are A. planes parallel to ( X Y ) plane B. planes parallel to ( Z Y ) plane C. planes parallel to ( X Z ) plane D. None of the above |
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| 524 | I nree laentıcal square metal plates ( M_{1}, M_{2} ) and ( M_{3} ) of side ( 10 mathrm{cm} & 5 mathrm{mm} ) thick are arranged as shown in figure. The plates are separated by sheets of paper ( 0.5 mathrm{mm} ) thick ( & ) of dielectric constant ( 5 . ) The outer plates are connected together ( & ) connected to lower potential while inner plate to higher potential terminal of a battery. Capacitance between the terminals of the battery is : ( left(epsilon_{0}=8.910^{-12} C^{2} / N-right. ) ( left.boldsymbol{m}^{2}right) ) A. ( 1780 p F ) В. ( 890 p F ) ( mathbf{c} .445 p F ) D. ( 222.5 p F ) |
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| 525 | 3. The velocity factor of a transmission line x. If dielectric constant of the medium is 2.6, the value of x is (a) 0.26 (b) 0.62 (c) 2.6 (d) 6.2 |
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| 526 | The electric potential at a point in free space due to a charge ( Q ) coulomb is ( Q times 10^{11} ) volts. The electric field at that point is – ( mathbf{A} cdot 4 pi epsilon_{0} times 10^{20} ) volt ( / mathrm{m} ) B . ( 12 pi epsilon_{0} times 10^{22} )volt( / m ) C . ( 4 pi epsilon_{0} times 10^{22} ) volt ( / m ) D . ( 12 pi epsilon_{0} times 10^{20} ) volt ( / m ) |
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| 527 | Two equal charges ( A ) and ( B ) each of ( 1 / 3 times 10^{-6} C ) are placed ( 200 mathrm{cm} ) apart in air. A particle carrying a charge of ( -1 / 3 times 10^{-6} C ) is projected along the perpendicular bisector from the point 0 midway between ( A ) and ( B ) with a kinetic energy of ( 10^{-3} J . ) Before the particle starts to return it will cover a distance A. ( 1 m ) B. ( sqrt{2} mathrm{m} ) c. ( sqrt{3} mathrm{m} ) D. ( 1 / sqrt{3} mathrm{m} ) |
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| 528 | How does the magnitude of the electric field at ( mathrm{B} ) compare for these three cases в. ।>॥>॥|| D. II>1>11 ( E cdot 1=11=11 ) |
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| 529 | The displacement of a charge ( Q ) in the electric field ( boldsymbol{E}=boldsymbol{e}_{1} boldsymbol{l}+boldsymbol{e}_{2} boldsymbol{j}+boldsymbol{e}_{3} boldsymbol{k} ) is ( boldsymbol{r}=boldsymbol{a} boldsymbol{i}+boldsymbol{b} boldsymbol{j} . ) The work done is A ( Qleft(a e_{1}+b e_{2}right) ) () ( aleft(a_{1}+b_{2}right)+b_{2}+b_{2} ) в. ( Q overline{a e_{1}^{2}+b e_{2}^{2}} ) c. ( Qleft(e_{1}+e_{2}right) overline{a^{2}+b^{2}} ) D. ( Q overline{e_{1}^{2}+e_{1}^{2}} a+b ) |
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| 530 | ( 4 mu F ) and ( 6 mu F ) capacitors are joined in series and ( 500 v ) are applied between the outer plates of the system. What is the charge on each plate? A ( cdot 1 cdot 2 times 10^{3} C ) в. ( 6 cdot 0 times 10^{3} C ) ( mathrm{c} cdot 5 cdot 0 times 10^{-3} mathrm{C} ) D. ( 2 cdot 0 times 10^{-3} C ) |
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| 531 | You measure the capacitor and inductor voltages in a driven RLC circuit, and find 10V for the rms capacitor voltage and ( 15 V ) for the ( r m s ) inductor voltage. A ( cdot omega=omega_{r e s} ) В. ( omegaomega_{r e s} ) D. can’t be said |
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| 532 | The potential at a point due to a charge of ( 5 times 10^{-7} ) C located ( 10 mathrm{cm} ) away is: A. ( 3.5 times 10^{5} mathrm{V} ) B. 3.5 ( times 10^{4} mathrm{v} ) c. ( 4.5 times 10^{4} v ) D. ( 4.5 times 10^{5} mathrm{v} ) |
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| 533 | When a steady current ( I ) flows through a resistor of resistance ( boldsymbol{R} ) under a constant potential difference ( V ) for time ( t, ) the electrical work done by charge carrier is ( W= ) A . ( V I t ) в. ( I^{2} R t ) ( c cdot frac{V^{2} t}{R} ) D. Any of these |
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| 534 | Find equivalent capacitance between points ( A ) and ( B: ) ( ^{A} cdot frac{5 C}{3} ) в. ( frac{4 C}{3} ) ( c cdot 2 C ) ( D . C ) |
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| 535 | What are polar and non polar dielectric give one example each other ?Define dielectric constants. |
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| 536 | Three charges ( -2 q, q, q ) are placed on the vertices of an equilateral triangle. At the incentre of the triangle, A. the field is zero but the potential is non-zero. B. the field is non-zero but the potential is zero. c. both the field and the potential is zero. D. both the field and the potential is non-zero |
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| 537 | The capacitance of a capacitor A. filled with a dielectric is lesser than it would be in a vacuum B. filled with a dielectric is greater than it would be in a vacuum c. filled with a dielectric is same as it would be in a vacuum. D. none of the above |
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| 538 | The charge stored in a capacitor is ( 20 mu C ) and the potential difference across the plates is ( 500 mathrm{V} ). Its capacity is : A. ( 0.04 mu F ) B . ( 10^{-2} mu F ) c. ( 2 times 10^{-6} mu F ) D. 250 muF |
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| 539 | ( frac{bar{k}}{k} ) | 12 |
| 540 | How does the amount of work needed to move this charge compare for these three cases? A. Most work required in B. Most work required in II C. Most work required in III D. I and II required the same amount of work but less than III E. All three would require the same amount of work |
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| 541 | n identical capacitors are connected in parallel to a potential difference ( V ) These capacitors are then reconnected in series, their charges being left undisturbed. The potential difference obtained is: A . zero B. (n-1)V ( c cdot n v ) D. ( n^{2} V ) |
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| 542 | For high frequency a capacitor offer A. more reactance B. less reactance c. zero reactance D. inifinite reactance |
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| 543 | Charges +50,+20,+30 and -100 nano coulomb are placed at the four corners of a square of side ( 5 sqrt{2} mathrm{cm} . ) The potential at the intersection of diagonals is : A ( cdot 1.8 sqrt{2} times 10^{4} V ) ( V ) B. ( 3.6 times 10^{4} V ) c. ( 1.8 times 10^{4} V ) D. Zero |
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| 544 | Which of the following is correct statement: A. Equipotential lines are always perpendicular to the electric field B. Work done for moving a charge along the conducting surface (closed and containing charge) very close to it may be negative or positive C. Electric field may cross each other D. None of the above |
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| 545 | A metal rod of length ( 10 mathrm{cm} ) and a rectangular cross section of ( 1 mathrm{cm} times frac{1}{2} ) ( mathrm{Cm} ) is connected to a battery across opposite faces. The resistance will be. A. Maximum when the battery is connected cross ( 1 mathrm{cm} ) ( times frac{1}{2} mathrm{cm} ) faces B. Maximum when the battery is connected across ( 10 mathrm{cm} ) ( times 1 mathrm{cm} ) faces c. Maximum when the battery is connected across ( 10 mathrm{cm} ) ( times frac{1}{2} mathrm{cm} ) faces D. Same irrespective of the three faces |
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| 546 | The quantity of heat generated in a conductor depends on A. square of the current ( left(I^{2}right) ) B. resistance of the conductor ( (R) ) c. time for which the mean flows ( (t) ) D. ( I^{2} R t ) |
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| 547 | Four charges, all of the same magnitude, are placed at the four corners of a square. At the centre of the square, the potential is ( mathrm{V} ) and the field is E. With suitable choices of the signs of the four charges, which of the following can be obtained? This question has multiple correct options A. ( V=0, E=0 ) B. ( V=0, E neq 0 ) c. ( V neq 0, E=0 ) D. ( V neq 0, E neq 0 ) |
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| 548 | Two capacitors ( C_{1} ) and ( C_{2} ) are connected in parallel. Assume that ( C_{1}<C_{2} . ) The equivalent capacitance of this arrangement is ( C, ) where A. ( C<C_{1} / 2 ) в. ( C_{1}<C<C_{1} ) c. ( C_{1}<C<C_{2} ) D. ( C_{2}<C<2 C_{2} ) |
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| 549 | Two parallel plate capacitors of capacitances ( C_{1} ) and ( C_{2} ) such that ( C_{1}=2 C_{2} ) are connected across a battery of ( V ) volts as shown in the figure. Initially the key ( ( k ) ) is kept closed to fully charge the capacitors. The key is now thrown open and a dielectric slab of dielectric constant ‘ ( K^{prime} ) is inserted in the two capacitors to completely fill the gap between the plates. The ratio of the energies stored in the combination, before and after the introduction of the dielectric slab: |
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| 550 | A parallel plate capacitor has a uniform electric field ( E ) in the space between the plates. If the distance between the plates is ( d ) and area of each plate is ( A ) the energy stored in the capacitor is : A ( cdot E^{2} A d / varepsilon_{0} ) в. ( frac{1}{2} varepsilon_{0} E^{2} A d ) ( mathbf{c} cdot varepsilon_{0} E A d ) D ( cdot frac{1}{2} varepsilon_{0} E^{2} ) |
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| 551 | Electric field inside the capacitor is 100 ( mathrm{V} / mathrm{m} ) and dielectric constant ( =5.5 ) What is the polarization? |
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| 552 | There is an infinite straight chain of alternating charges ( q ) and ( -q ) The distance between the two neighbouring charges is equal to a. Find the interaction energy of any charge with all the other charges. A ( cdot frac{2 q^{2}}{4 pi varepsilon_{0} a} ) B ( cdot frac{2 q^{2} log _{e} 2}{4 pi varepsilon_{0} a} ) ( ^{mathbf{C}}-frac{2 q^{2} log _{e} 2}{4 pi varepsilon_{0} a} ) D. none of these |
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| 553 | There are four concentric shells ( A, B, C ) and D of radii a, ( 2 a, 3 a ) and ( 4 a ) respectively. Shells B and D are given charges ( +q ) and ( -q ) respectively. Shell ( C ) is now earthed. The potential difference ( V_{A}-V_{c} ) is ( k=frac{1}{4 pi varepsilon_{0}} ) A ( cdot frac{k q}{2 a} ) в. ( frac{k q}{3 a} ) ( c cdot frac{k q}{4 a} ) D. ( frac{k q}{6 a} ) |
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| 554 | A parallel-plate capacitor has capacitance of ( 1.0 mathrm{F} ). If the plates are 1.0 ( mathrm{mm} ) apart, what is the area of the plates? |
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| 555 | Three capacitors each of capacitance ( 9 p F ) are connected in series as shown in figure. (a) What is the total capacitance of the combination? (b) What is the potential difference across each capacitor, if the combination is connected to a 120 volt supply? |
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| 556 | Determine ( boldsymbol{V}(boldsymbol{x}) ) A . ( 20 x ) B . ( -20 x ) c. ( 10 x ) D. ( -10 x ) |
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| 557 | There are four large parallel conducting plates each of Area A, placed parallel to each other. Plates 1,2,3,4 are given charges equal to ( boldsymbol{q}_{1}, boldsymbol{q}_{2}, boldsymbol{q}_{3} ) and ( boldsymbol{q}_{4} ) respectively: This question has multiple correct options A. Charge appearing on the left hand side of plate 1 will be ( frac{q_{1}+q_{2}+q_{3}+q_{4}}{2} ) B. Electric field intensity at the point ( P ), towards right, will be ( frac{q_{1}+q_{2}-q_{3}-q_{4}}{2 A varepsilon_{0}} ) C. Electric field intensity at the point ( Q ), towards right, will be ( frac{q_{1}-q_{2}+q_{3}+q_{4}}{2 varepsilon_{0}} ) D. Electric field at P will be equal to that at Q, for any values of ( q_{1}, q_{2}, q_{3} ) and ( q_{4} ) |
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| 558 | Two conducting plates ( A ) and ( B ) are placed parallel to each other at a small distance between them. Plate A is given a charge ( q_{1} ) and plate ( B ) is given a charge ( boldsymbol{q}_{2} . ) Then : This question has multiple correct options |
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| 559 | The electric potential at a distance of ( 3 m ) on the axis of a short dipole of dipole moment ( 4 times 10^{-12} ) coulomb- metre is A ( cdot 1.33 times 10^{-3} V ) ( V ) B. ( 4 m V ) c. ( 12 m V ) D. ( 27 mathrm{mV} ) |
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| 560 | Which of the following statement is not true? A. Electrostatic force is a conservative force. B. Potential at a point is the work done per unit charge in bringing a charge from infinity to that point in an electric field. C. Electrostatic force is non-conservative. D. Potential is the ratio of work to charge. |
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| 561 | Consider the situation shown in the figure. The capacitor A has a charge ( q ) on it, whereas ( mathrm{B} ) is uncharged. The charge appearing on the capacitor ( mathrm{B} ), after a long time of closing the switch is: A. zero B. ( frac{q}{2} ) ( c cdot q ) D. ( 2 q ) |
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| 562 | A ( 1 mu F ) capacitor is charged to 200 V and then connected in parallel (+ve to +ve) with a ( 4 mu F ) capacitor charged to ( 100 mathrm{V} ) The resultant potential difference is : A. ( 120 mathrm{V} ) B. 60 c. ( 180 v ) D. ( 150 mathrm{v} ) |
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| 563 | A hollow insulated conduction sphere is given a positive charge of ( 10 mu C . ) What will be the electric field at the centre of the sphere if its radius is 2 metres? A. zero в. ( 5 mu C m^{-2} ) ( c cdot 20 mu C m^{-2} ) D. ( 8 mu C m^{-2} ) |
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| 564 | Two charges ( +6 mu C ) and ( -4 mu C ) are placed ( 15 c m ) a part as shown. At what distances from ( A ) to its right, the electrostatic potential is zero? ( mathbf{A} cdot 4,9,60 ) B. 9,15,45 ( mathrm{C} cdot 20,30,40 ) D. ( 9,45, ) infinity |
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| 565 | The plates of a parallel-plate capacitor are made of circular discs of radii 5.0 ( mathrm{cm} ) each. If the separation between the plates is ( 1.0 mathrm{mm}, ) what is the capacitance? |
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| 566 | Q Type your question between its plates that covers ( 1 / 3 ) of the area of its plates, as shown in the figure. The total capacitance of the capacitor is ( C ) while that of the portion with dielectric in between is ( mathrm{C}_{1} ). When the capacitor is charged, the plate area covered by the dielectric gets charge ( Q_{1} ) and the rest of the area gets charge ( Q_{2} ) The electric field in the dielectric is ( mathrm{E}_{1} ) and that in the other portion is ( mathrm{E}_{2} ) Choose the correct option/options, ignoring edge effects: This question has multiple correct options A ( cdot frac{E_{1}}{E_{2}}=1 ) В. ( frac{E_{1}}{E_{2}}=frac{1}{K} ) C. ( frac{Q_{1}}{Q_{2}}=frac{3}{K} ) D. ( frac{C}{C_{1}}=frac{2+K}{K} ) |
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| 567 | A ( 4 mu F ) capacitor is charged to ( 400 V . ) If its plates are joined through a resistance ( 2 k Omega, ) then heat produced in the resistance is ( mathbf{A} cdot 0.16 J ) в. ( 0.32 J ) c. ( 0.64 J ) D. ( 1.28 J ) |
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| 568 | Two charges – ( q ) and ( +q ) are located at points ( (0,0,-a) ) and ( (0,0, a) ) respectively. (a) What is the electrostatic potential at the points ( (0,0, z) ) and ( (x, y, 0) ? ) (b) Obtain the dependence of potential on the distance r of a point from the origin when ( r / a>>1 ) (c) How much work is done in moving a small test charge from the point (5,0,0) to (-7,0,0) along the ( x ) -axis? Does the answer change if the path of the test charge between the same points is not along the x-axis? |
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| 569 | With ( V=0 ) at infinity, what is the electric potential at corner A? A ( cdot 6 times 10^{4} V ) В. ( -7.8 times 10^{5} V ) c. ( 8.4 times 10^{5} V ) D. None of these |
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| 570 | The electric potential decreases uniformly from ( 120 mathrm{V} ) to ( 80 mathrm{V} ) as one moves on the X-axis from ( x=-1 c m ) to ( boldsymbol{x}=+1 mathrm{cm} . ) The electric field at the origin. A. must be equal to ( 20 V / c m ) B. must be equal to ( 2.0 mathrm{V} / mathrm{cm} ) c. must be greater than ( 20 V / mathrm{cm} ) D. must be less than ( 20 mathrm{V} / mathrm{cm} ) |
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| 571 | Positive and negative point charges of equal magnitude are kept at ( left(0,0, frac{a}{2}right) ) and ( left(0,0, frac{-a}{2}right), ) respectively. The work done by the electric field when another positive point charge is moved from ( (-a, 0,0) ) to ( (0, a, 0) ) is: A. positive B. negative c. zero D. depends on the path connecting the initial and final positions |
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| 572 | Find the charge appearing on the inner face of the left plate: A ( cdot C V-Q_{1} ) в. ( C V+Q_{1} ) c. ( _{C V}-frac{Q_{1}}{2} ) D. ( C V ) |
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| 573 | Two point charges ( q_{1} ) and ( q_{2} ) are located at ( overrightarrow{r_{1}} ) and ( overrightarrow{r_{2}} ) respectively in an external electric field ( E ).Total work done in assembling this configuration ( frac{boldsymbol{E}left(boldsymbol{q}_{1}+boldsymbol{q}_{2}right)}{boldsymbol{delta l}} . ) Type 1 for true and 0 for false |
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| 574 | A parallel plate condenser with oil (dielectric constant 2 ) between the plates has capacitance ( C . ) If the oil is removed, the capacitance of capacitor becomes: A. ( sqrt{2 C} ) B. 2C c. ( frac{c}{sqrt{2}} ) D. ( frac{c}{2} ) |
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| 575 | In a parallel plate capacitor, the region between the plates is filled by a delectric slab. The capacitor is connected to a cell and the slab is taken out. A. Some charge is drawn from the cell B. Some charge is returned to the cell c. The potential difference across the capacitor is reduced D. No work is done by an external agent in taking the slab out |
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| 576 | TWO point charges ( +2 n c ) and ( -4 n c ) are 1 ( m ) apart in air. Find the positions along the line joining the two charges at which resultant potential is zero. |
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| 577 | Assertion For practical purposes, the earth is used as a reference at zero potential in electrical circuits. Reason The electric potential of a sphere of radius ( R ) with charge ( Q ) uniformly distributed on the surface is given by ( frac{Q}{4 pi varepsilon_{0} R} ) A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect and Reason are correct |
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| 578 | Four identical plates each of area a are separated by a distance d. The connection is shown below. What is the capacitance between ( mathrm{P} ) and ( mathrm{Q} ) ? A ( cdot 2 a in_{0} / d ) B ( cdot a epsilon_{0} /(2 d) ) ( mathrm{c} cdot a epsilon_{0} / d ) D. ( 4 a in_{0} / d ) |
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| 579 | Two parallel plate air capacitors of same capacity’ ( C^{prime} ) are connected in series to a battery of emf ‘ ( E^{prime} . ) Then one of the capacitors is completely filled with dielectric material of constant ( ^{prime} boldsymbol{K}^{prime} ) The change in the effective capacity of the series combination is A ( cdot frac{C}{2}left[frac{K-1}{K+1}right] ) B ( cdot frac{2}{C}left[frac{K-1}{K+1}right] ) c. ( frac{C}{2}left[frac{K+1}{K-1}right] ) ( ^{mathrm{D}} cdot frac{C}{2}left[frac{K-1}{K+1}right]^{2} ) |
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| 580 | As shown in the figure, charges ( +q ) and ( q ) are placed at the vertices ( B ) and ( C ) of an isosceles triangle. The potential at the vertex ( A ) is ( A ) в. ( frac{1}{4 pi varepsilon_{0}} cdot frac{q}{sqrt{a^{2}+b^{2}}} ) ( c ) D. zero |
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| 581 | The electrostatic potential due to the charge configuration ot point ( P ) as shown in figure for ( b<<a ) is ( A ) [ frac{2 q}{4 pi varepsilon_{0} a} ] B. [ frac{2 q b^{2}}{4 pi varepsilon_{0} a^{3}} ] ( c ) [ frac{q b^{2}}{4 pi varepsilon_{0} a^{3}} ] D. zero |
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| 582 | A spherical drop of water carrying a charge of 0.032 nC has a potential of 512 V at its surface. If two such drops with the same radius and charge were to combine to form a single drop, what would be the potential at the surface of the new drop? A . 136.2 ( v ) в. 113 v c. ( 999.08 mathrm{v} ) D. 812.756 V |
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| 583 | The charge on solid sphere is A ( cdot-9 / 2 ) B. – -व/4 ( c cdot-q / 8 ) D. – q/16 |
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| 584 | The capacity between two adjacent plates of parallel plate condenser is ( 5 mu F ). The number of plates used if we want to get a capacity of ( 40 mu F ) are (alternate plates are connected together): ( A cdot 8 ) B. 9 ( c cdot 7 ) D. 10 |
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| 585 | A parallel plate capacitor has a dielectric (of dielectric constant ( k ) ) between the plates. The plates are charged to a surface charge density ( sigma_{0} ) What is the density of the polarized charge that appear on the surface of the dielectric. |
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| 586 | Four identical plates each of area ( a ) are separated by a distance ( d ). The connection is shown below. What is the capacitance between ( P ) and ( Q ? ) A ( cdot frac{2 a varepsilon_{0}}{d} ) B. ( frac{a varepsilon_{0}}{2 d} ) c. ( frac{varepsilon_{0}}{d} ) D. ( frac{4 a varepsilon_{0}}{d} ) |
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| 587 | Two concentric conducting shells A and B are of radii Rand 2 R. A charge ( + ) q is placed at the centre of the shells Shell B is earthed and a charge q is given to shell A. The charge on outer surface of A is ( n q ), find ( n ) |
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| 588 | Eight identical spherical mercury drops charged to a potential of 20 v each are coalesced into a single spherical drop: A. The internal Energy of the system remains the same B. The new potential of the drop is 80 v c. Internal Energy of he system decreases D. The potential remains the same i.e. ( 20 mathrm{v} ) |
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| 589 | Four metallic plate each with a surface area of ( A ) are placed at a distance ( d ) from each other. The plates are connected as shown in the circuit diagram. Then the capacitance of the system between a and b is- ( mathbf{A} cdot frac{3 epsilon_{0} A}{d} ) В. ( frac{2 epsilon_{0} A}{d} ) ( mathbf{c} cdot frac{2 epsilon_{0} A}{3 d} ) D. ( frac{3 epsilon_{0} A}{2 d} ) |
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| 590 | A capacitor, as shown in figure has square plates of length land are inclined at an angle ( theta ) with one another. For small value of ( theta, ) capacitance is given by: ( ^{mathbf{A}} cdot frac{epsilon_{0} l^{2}}{d}left(1-frac{theta l}{2 d}right) ) ( ^{mathbf{B}} cdot frac{epsilon_{0} l^{2}}{2 d}left(1-frac{theta l}{d}right) ) c. ( frac{epsilon_{0} l^{2}}{d}left(1+frac{theta l}{d}right) ) D ( cdot frac{epsilon_{0} l^{2}}{2 d}left(1+frac{theta l}{d}right) ) |
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| 591 | The work done in bringing a unit positive charge from infinite distance to a point at distance ( x ) from a positive charge ( Q ) is ( W ). Then the potential ( phi ) at that point is: A. ( frac{W Q}{x} ) B. ( W ) c. ( frac{W}{x} ) D. ( W Q ) |
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| 592 | The plates of a parallel plate condenser are pulled apart with a velocity v. If at any instant their mutual distance of separation is ( x, ) the magnitude of the time of rate of change of capacity depends on ( x ) as follows: ( A cdot 1 / x ) B . ( 1 / x^{2} ) c. ( x^{2} ) D. |
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| 593 | Calculate the amount of work done in carrying a charge of ( 5 mathrm{mC} ) against a potential difference of ( 100 V ) A. ( 0.5 . ) J в. ( 50 J ) c. ( 5 J ) D. None |
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| 594 | What is the electric potential at the center of the triangle in figure |
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| 595 | The equivalent capacitance between ( mathrm{P} ) and ( Q ) is ( A cdot frac{C}{3} ) в. ( 3 C ) ( c .2 C ) D. |
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| 596 | The velocity factor of a transmission line is ( 0.62 . ) Calculate dielectric constant of the insulation used A . 2.6 B. 3 ( c cdot 4 ) D. 5 |
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| 597 | Which of the following quantities are independent of the choice of zero potential or zero potential energy? This question has multiple correct options A. Potential at a point B. Potential difference between two points. c. Potential energy of a two charge system. D. change in potential energy of a two charge system. |
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| 598 | A capacitor of capacitance ( C ) is charged to a potential difference ( V ) from a cell and then disconnected from it. A charge ( +Q ) is now given to its positive plate. The potential difference across the capacitor is now A. ( V ) B. ( V+frac{Q}{C} ) c. ( _{V}+frac{Q}{2 C} ) D. ( V-frac{Q}{C}, ) if ( Q<C V ) |
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| 599 | Three particles, each having a charge of ( 10 C ) are placed at the corners of an equilateral triangle of side ( 10 mathrm{cm} ). The electrostatic potential energy of the system is : A . ( 100 J ) В. ( 27 times 10^{12} J ) c. 0 ( D cdot infty ) |
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| 600 | ( frac{sqrt{x}}{frac{x}{3}} ) | 12 |
| 601 | The equivalent capacitance between AB of the combination shown in figure is ( A ) B. 2C ( c cdot c / 2 ) D. none of thes |
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| 602 | State whether true or false: The unit of voltage is ( J C^{-1} ) |
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| 603 | How much work is done moving an electron from a potential of ( 2 mathrm{V} ) to ( 5 mathrm{V} ) ? A . 2ev B. 3ev c. ( 5 mathrm{ev} ) D. 10ev |
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| 604 | A metal sphere of ( 4 mathrm{cm} ) radius is suspended within a hollow sphere of 6 cm radius. The inner sphere is charged to potential 3 esu and the outer sphere is earthed. The charge on the inner sphere is A . 54 esu B. 1/4 esu ( c . ) 30 esu D. 36 esu |
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| 605 | A ( 5.80 mu F ) parallel-plate air capacitor has a plate separation of ( 5.00 mathrm{mm} ) and is charged to a potential difference of ( 400 mathrm{V} . ) Calculate the energy density in the region between the plates, in ( J / m^{3} ) |
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| 606 | The separation between the plates of a charged parallel plate capacitor is increased. The force between the plates A. increases B. decreases c. remains same D. first increases then decreases |
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| 607 | No charge will flow when two conductors having the same charge are connected to each other Given statement is: A. True B. False |
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| 608 | The work done in carrying 20 coulomb charge through a distance of ( 5 mathrm{m} ) is ( 2 J ) The potential difference between these two points will be: ( mathbf{A} cdot 2 times 10^{-1} V ) B. ( 1 times 10^{-2} V ) c. ( 2 times 10^{-2} V ) D. ( 1 times 10^{-1} V ) |
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| 609 | toppr Q Type your question. lower half. The electric field lines around the cylinder will look like figure given in (figures are schematic and not drawn to scale) ( A ) B. ( c ) ( D ) |
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| 610 | The equivalent capacitance between ( x ) and ( y ) is : ( A cdot 5 / 6 mu F ) B. ( 7 / 6 mu F ) ( c cdot 8 / 3 mu F ) D. ( 1 mu F ) |
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| 611 | (a) Deduce the expression for the potential energy of a system of two charges ( q_{1} ) and ( q_{2} ) located ( overrightarrow{r_{1}} ) and ( overrightarrow{r_{2}} ) respectively, in an external electric field. (b) Three point charges, ( +Q+2 Q ) and ( 3 Q ) are placed at the vertices of an equilateral triangle ABC of side I. If these charges are displaced to the mid- point ( A_{1}, B_{1} ) and ( C_{1}, ) respectively, find the amount of the work done in shifting the charges to the new locations. |
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| 612 | On what factors does the capacitance of a parallel plate capacitors depends? |
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| 613 | Three concentric spherical conductors are shown in figure. Determine the equivalent capacitance of the system between ( B ) and ( C ). |
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| 614 | The diagrams below show regions of equipotentials. A positive charge is moved from ( A ) to ( b ) in each diagram. A. Maximum work is required to move ( q ) in figure (b) B. Maximum work is required to move ( q ) in figure(c) ( mathrm{c} . ) In all the cases the work done is the same D. Minimum work is required to move ( q ) in figure(a) |
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| 615 | Two capacitors of ( 1 mu F ) and ( 2 mu F ) are connected in series and this combination is changed upto a potential difference of 120 volt. What will be the potential difference across ( 1 mu F ) capacitor: A . ( 40 v o l t ) B. 60 volt c. ( 80 v ) olt D. ( 120 v o l t ) |
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| 616 | A parallel plate capacitor is made of two square plates of side ‘ ( a ) ‘, separated by a distance ( d(d<<a) ). The lower triangular portion is filled with a dielectric of dielectric constant ( boldsymbol{K}, ) as shown in the figure. The capacitance of this capacitor is : ( mathbf{A} cdot frac{1}{2} frac{k in_{0} a^{2}}{d} ) B. ( frac{k in_{0} a^{2}}{d} ln K ) c. ( frac{k in_{0} a^{2}}{d(K-1)} ln K ) D. ( frac{k in_{0} a^{2}}{2 d(K+1)} ) |
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| 617 | A parallel plate capacitor of capacitance C consists of two identical plates ( A ) and ( B ). A charge ( q ) is given to plate ( A ) and charge ( -2 q ) is given to plate B. The space between plates is vacuum. The separation between plates is d. The electric intensity at a point situated between plates is? A ( cdot frac{q}{C d} ) в. ( frac{q}{2 C d} ) c. ( frac{3 q}{2 C d} ) D. None of these |
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| 618 | A parallel plate condenser is immersed in an oil of dielectric constant 2. The field between the plates is : A ( cdot ) increased, proportional to ( frac{1}{2} ) B. decreased, proportional to – 2 c. increased, proportional to – 2 D. decreased, proportional to ( -frac{1}{2} ) |
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| 619 | What is the potential difference across a 64.0 microfarad capacitor if the charge on the positive plate is +16.0 microcoulombs? A. ( 4.0 V ) B. ( 0.25 V ) ( c .1024 V ) D. ( 2.0 V ) E . ( 32.0 V ) |
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| 620 | Assertion: Two concentric charged shells are given. The potential difference between the shells depends on charge of inner shell. Reason: Potential due to charge of outer shell remains same at every point inside the sphere. A. Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion B. Both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion c. Assertion is true statement but Reason is false D. Both Assertion and Reason are false statements |
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| 621 | Three point charges ( +boldsymbol{q},+mathbf{2} boldsymbol{q} ) and ( -mathbf{4 q} ) where ( boldsymbol{q}=mathbf{0 . 1} boldsymbol{mu} boldsymbol{C}, ) are placed at the vertices of an equilateral triangle of side ( 10 mathrm{cm} ) as shown in figure. The potential energy of the system is A ( cdot 3 times 10^{-3} J ) В. ( -3 times 10^{-3} J ) ( mathbf{c} cdot 9 times 10^{-3} J ) ( mathbf{D} cdot-9 times 10^{-3} mathbf{J} ) |
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| 622 | The amount of work done in moving a unit positive charge from infinity to a given point is known as: A. Nuclear potential B. Potential energy c. Electric potential D. Gravitational potential |
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| 623 | Three charged particles are initially in position-1. They are free to move and they come to position – 2 , after some time.Let ( U_{1} ) and ( U_{2} ) be the electrostatic potential energies in position-1 and 2.Then A ( cdot U_{1}=U_{2} ) в. ( U_{2} geq U_{1} ) c. ( U_{2}>U_{1} ) D. ( U_{1}>U_{2} ) |
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| 624 | Two capacitators having capacitances ( C_{1} ) and ( C_{2} ) are charged with ( 120 V ) and ( 200 V ) batteries respectively. When they are connected in parallel now, it is found that the potential on each one of them is zero. Then: A ( cdot 8 C_{1}=5 C_{2} ) В. ( 9 C_{1}=5 C_{2} ) ( mathbf{c} cdot 3 C_{1}=5 C_{2} ) D. ( 5 C_{1}=3 C_{2} ) |
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| 625 | toppr Q Type your question by ( A ) B. ( mathbf{c} ) ( D ) |
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| 626 | When a small uncharged conducting ball of radius ( a=1 c m ) and mass ( m=50 ) g is dropped from a height h above the center of another large conducting sphere of radius b ( (=1 mathrm{m}) ) having charge ( Q(=100 mu C), ) it rises to a height ( h_{1} in ) ( 2 m ) ) after the collision. The value of h is ( mathbf{1 0} ) Find ( x ) Assume that during the impact there is no dissipation of energy. |
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| 627 | A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved further apart by means of insulating handles, then: A. the charge in the capacitor becomes zero B. the capacitance becomes infinite C. the charge in the capacitor increases D. the voltage across the plates increases |
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| 628 | An electric dipole is kept in the origin with charges along the ( x ) axis, now choose the correct option, A. equipotential surface is on ( x y ) plane B. equipotential surface is on ( x z ) plane c. equipotential surface is on ( y z ) plane D. none of the above |
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| 629 | Derive an expression for effective capacitance of three capacitors connected in parallel |
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| 630 | Out of the given statements which of the following are true: A) Work done in moving a charge on equipotential surface is zero. B) Electric lines of force are always normal to equipotential surface. C) When two like charges are brought closer, the electrostatic potential energy of the system is decreased. D) Electric lines of force converge at positive charge and diverge at negative charge. ( A cdot A, B, C, D ) are true B. ( A, B, C ) are true c. ( A, B ) are true D. A only true |
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| 631 | A dielectric of thickness ( 5 mathrm{cm} ) and a dielectric constant 10 is introduced between the plates of a parallel plate capacitor having plate area 500 sq. ( mathrm{cm} ) and separation between the plates ( 10 mathrm{cm} ) The capacitance of the capacitor with the dielectric slab is ( varepsilon_{0}=8.8 times 10^{-12} C^{2} / N- ) ( m^{2} ) A ( .4 .4 p F ) B. ( 6.2 p F ) c. ( 8 p F ) D. ( 10 p F ) |
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| 632 | 1 volt is equal to A .1 Joule B. ( frac{1 text { Joule}}{1 text { Coulomb }} ) c. ( frac{1 text { Joule}}{1 text { meter }} ) D. ( frac{1 text { Newton }}{1 text { Coulomb }} ) |
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| 633 | The radius of a hypothetical nucleus (atomic number= 79 ) is about ( 7 times ) ( 10^{-15} mathrm{m} . ) Assuming that charge distribution is uniform, the electric field at the surface of the nucleus is : A. ( 2.9 times 10^{-21} ) B. ( 2.32 times 10^{21} ) C. ( 4.64 times 10^{21} ) D. |
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| 634 | Two metal spheres (radii ( r_{1}, r_{2} ) with ( left.r_{1}<r_{2}right) ) are very far apart but are connected by a thin wire. If their combined charge is ( Q ), then what is their common potential? A ( cdot k Q /left(r_{1}+r_{2}right) ) B . ( k Q /left(r_{1}-r_{2}right) ) ( mathbf{c} cdot-k Q /left(r_{1}+r_{2}right) ) D. ( -k Q / r_{1} r_{2} ) |
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| 635 | Which of the particles would move to the right? A. I and II only B. I and III only c. II and III only D. II only E. I only |
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| 636 | Fill in the blank: In order to increase the capacity of a parallel plate condenser, one should introduce a sheet of between the plates (assume that the space is completely filled). A. Mica B. Tin c. copper D. Stainless Steel |
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| 637 | A hollow closed conductor of irregular shape is given some charge. Which of the following statements are correct? This question has multiple correct options A. The entire charge will appear on its outer surface B. All points on the conductor will have the same potential c. All points on its surface will have the same charge density D. All points near its surface and outside it will have the same electric intensity |
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| 638 | A dielectric with a dielectric constant of ( k ) is inserted between the plates of the capacitor of capacitance ( C ) having a potential difference of ( Delta V ) between the two plates. Calculate the energy stored in the capacitor? A ( cdot frac{1}{2}(C / k)(Delta V)^{2} ) B ( cdot frac{1}{2}(k / C)(Delta V)^{2} ) ( ^{mathrm{c}} cdot frac{1}{2} k C(Delta V)^{2} ) D. ( frac{1}{2} k C Delta V ) E ( cdot frac{1}{2}(C / k) Delta V ) |
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| 639 | The potential across a 25.0 microfarad capacitor is ( 5.0 V . ) What is the charge on the capacitor? A. 0.20 microcoulombs B. 5.0 microcoulombs c. 125 microcoulombs D. 30.0 microcoulombs E. We cannot determine the charge on the capacitorwith the given information |
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| 640 | Relation between relative permitivity ( left(mu_{r}right) ) and magnetic susceptibility ( left(X_{m}right) ) |
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| 641 | The amount of work done in joules, when one unit electric charge moves from one point to another point in an electric circuit is called: A . electric current B. electric resistance c. electric conductance D. potential difference |
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| 642 | Why must the electrostatic potential inside a hollow charged conductor be the same at every point? |
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| 643 | The top of the atmosphere is about 400 kV with respect to the surface of earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth the field is about ( 100 mathrm{V} mathrm{m}^{-1}, ) but still dont get an electric shock, as we set out of our houses in to open because : (assume the house is free from electric field) A. Our body is a perfect insulator B. Our body and ground form an equipotential surface C. The original equipotential surfaces of open air remain same D. None of the above |
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| 644 | Two points ( A ) and ( B ) are located in diametrically opposite directions of a point charge of ( +2 mu mathrm{C} ) at distances ( 2 mathrm{m} ) and ( 1 mathrm{m} ) respectively from it. The potential difference between ( A ) and ( B ) is A. ( 3 times 10^{3} vee ) В. ( 6 times 10^{4} mathrm{V} ) ( mathbf{c} cdot-9 times 10^{3} mathbf{v} ) D. ( -3 times 10^{3} mathrm{v} ) |
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| 645 | A point-charge of ( 6.0 times 10^{-8} mathrm{C} ) is situated at the coordinate origin. How much work will be done in taking an electron from the point ( x=3 mathrm{m} ) to ( x=6 ) ( mathrm{m} ? ) B . ( 1.44 times 10^{-27} ) J c. ( 1.44 times 10^{-37} ) J D. ( 1.44 times 10^{-7} ). |
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| 646 | Two capacitors of capacitance ( C_{1} ) and ( C_{2} ) are connected in parallel across a battery. If ( Q_{1} ) and ( Q_{2} ) respectively be the charges on the capacitors, then ( frac{Q_{1}}{Q_{2}} ) will be equal to : A. ( frac{C_{2}}{C_{1}} ) в. ( frac{C_{1}}{C_{2}} ) c. ( frac{C_{1}^{2}}{C_{2}^{2}} ) D. ( frac{C_{2}^{2}}{C_{1}^{2}} ) |
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| 647 | Three charges ( 2 q,-q,-q ) are located at the vertices of an equilateral triangle. At the centre of the triangle : A. the field is zero but potential is nonzero B. the field is nonzero but potential is zero c. both field and potential are zero D. both field and potential are nonzero |
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| 648 | An ( alpha ) -particle of charge ( 2 e ) is projected with high speed towards two protons (each of charge ( e ) ) kept at a distance ( 4 m ) apart, along a perpendicular passing through the mid-point of the line joining the protons. Initially, ( alpha ) particle starts very far away from the protons. The change In potential energy of the system, when the ( alpha ) -particle undergoes the greatest repulsion, in terms of ( frac{mathbf{e}^{2}}{pi epsilon_{0}} ) will be: A ( cdot frac{1}{sqrt{3}} ) B. ( sqrt{2} ) c. ( frac{1}{sqrt{6}} ) D. ( sqrt{3} ) |
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| 649 | The particle of mass ( m ) and charge ( q ) will touch the infinitely large plate of uniform charge density ( sigma ) if its velocity ( v ) is more than:(Given that ( sigma q>0 ) ) A . 0 в. ( sqrt{frac{4 sigma q d}{m varepsilon_{0}}} ) c. ( sqrt{frac{sigma q d}{m varepsilon_{o}}} ) D. none of these |
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| 650 | The electric potential at a certain distance from a point charge ( Q ) is ( 810 V ) and electric field is ( 300 N / C ). The minimum speed with which a particle of charge ( -Q ) and mass ( m=6 x ) ( 10^{-16} k g ) should be projected from that point so that it moves into the field free region is: A ( cdot 9 times 10^{6} m / s ) в. ( 81 times 10^{6} mathrm{m} / mathrm{s} ) c. ( 81 times 10^{4} m / s ) D. ( 9 times 10^{4} m / s ) |
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| 651 | Highlousuelto thaligic ul olut ( u ) lias charges ( boldsymbol{q},+2 boldsymbol{q} ) and ( -boldsymbol{q} ) arranged on its vertices, as shown.What does the sign of ( U ) signify? A. The negative sign means that work was done on the agent who assembled these charges in moving them in from infinity. B. The positive sign means that work was done on the agent who assembled these charges in moving them in from infinity C. The negative sign means that work was done by the agent who assembled these charges in moving them in from infinity D. The positive sign means that work was done by the agent who assembled these charges in moving them in from infinity |
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| 652 | Dimension of capacitance is? A ( cdot M^{-1} L^{-2} A^{2} T^{4} ) B. ( M L^{2} A^{-2} T^{-4} ) c. ( M L A^{-1} T^{4} ) D. ( M^{-1} L^{-1} A^{2} T^{2} ) |
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| 653 | Capacity of a parallel capacitor with dielectric constant 5 is ( 40 mu F . ) Calculate the capacity of the same capacitor when dielectric material is removed. |
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| 654 | Find ( C_{A B} ) in the given circuit of given figure. Assume each capacitor is ( mathrm{C} ) A ( cdot frac{15 C}{8} ) B. ( frac{15 C}{7} ) c. ( frac{3 C}{2} ) D. ( 2 C ) |
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| 655 | The figure shows an infinite line charge of density ( C / m . ) The work done by the electrostatic force on a unit charge, when it is moved along the path ( boldsymbol{A B C} ) is (plane of the curve ( A B C ) contains the line charge) ( A cdot ) zero B. ( frac{-sigma}{2 pi epsilon_{o}} ln 2 ) c. ( frac{-sigma}{2 pi epsilon_{o}} ln 3 ) D. ( frac{sigma}{2 pi epsilon_{o}} ln 2 ) |
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| 656 | A parallel plate capacitor of capacitance ( 5 mu F ) and plate separation ( 6 mathrm{cm} ) is connected to a ( 1 mathrm{V} ) battery and charged. A dielectric of dielectric constant 4 and thickness ( 4 mathrm{cm} ) is introduced between the plates of the capacitor. The additional charge that flows into the capacitor from the battery is A. ( 2 mu C ) в. ( 3 mu C ) ( c cdot 5 mu C ) D. 10 ( mu C ) |
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| 657 | In the circuit shown in figure charge stored in the capacitor of capacity 5 muf is ( A cdot 60 mu C ) В. ( 20 mu C ) ( c .30 mu C ) ( D ) |
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| 658 | Calculate the work done to move a charge 5 C between two points ( A ) and ( B ), if both the points are maintained at same potential of ( 6 mathrm{V} ) A. zero B . 6 J c. 3 J D. 12 J |
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| 659 | toppr LOGIN JolN Now Q Type your question_ changes that will take place as a result of the increased plate separation? ( mathbf{A} ) begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor Property } & Effect of Increased Plate Separation \ hline Charge on Plates & increase \ Voltage Across Plates & no effect \ Capacitance & increase \ hline end{tabular} B. begin{tabular}{|l|l|} hline Capacitor Property & Effect of Increased Plate Separation \ hline Charge on Plates & no effect \ Voltage Across Plates & increase \ Capacitance & decrease \ hline end{tabular} ( c ) begin{tabular}{|l|l|} hline multicolumn{1}{|c|} { Capacitor Property } & Effect of Increased Plate Separation \ hline Charge on Plates & increase \ Voltage Across Plates & decrease \ Capacitance & no effect \ hline end{tabular} D. begin{tabular}{|l|l|} hline Capacitor Property & Effect of Increased Plate Separation \ hline Charge on Plates & decrease \ Voltage Across Plates & increase \ Capacitance & no effect \ hline end{tabular} ( E ) begin{tabular}{|l|l|} hline Capacitor Property & Effect of Increased Plate Separation \ hline Charge on Plates & no effect \ Voltage Across Plates & decrease \ Capacitance & increase \ hline end{tabular} |
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| 660 | Let ( U_{a} ) and ( U_{d} ) be the energy densities in air and in a dielectric of constant k for same field. Then ( mathbf{A} cdot U_{a}=U_{d} ) в. ( U_{a}=k U_{d} ) ( mathbf{c} cdot U_{d}=k U_{a} ) D. ( U_{a}=(k-1) U_{d} ) |
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| 661 | The resultant capacity between the terminals ( P ) and ( Q ) of the given figure is : A ( .37 mu F ) в. ( frac{15}{7} mu F ) ( c .3 mu F ) D. ( frac{30}{9} mu F ) |
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| 662 | Charge ( Q ) taken from the battery of 12 V in the circuit is : ( mathbf{A} cdot 72 mu C ) B. ( 36 mu C ) ( c cdot 156 mu C ) D. ( 20 mu C ) |
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| 663 | Two capacitors of unknown capacitances ( C_{1} ) and ( C_{2} ) are connected first in series and then in parallel across a battery of ( 100 mathrm{V} ). If the energy stored in two combinations is 0.045 and 0.25 J respectively, determine the value of ( C_{1} ) and ( C_{2} . ) Also calculate the charge on each capacitor in parallel combination. |
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| 664 | Three charges ( 1 mu C, 2 mu C, ) and ( 3 mu C ) are kept at vertices of an equilateral triangle of side ( 1 mathrm{m} ). If they are brought nearer, so that they now form an equilateral triangle of side ( 0.5 m, ) then work done is : A. ( 0.11 J ) ( J ) в. ( 11 J ) c. ( 0.01 J ) D. ( 1.1 mathrm{J} ) |
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| 665 | When an ideal capacitor is charged by dc battery, no current flows, However, When an ac source is used, the current flows continuously. How does one explain this, based on the concept of displacement current? |
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| 666 | Force between two plates of a capacitor is : A. ( frac{Q}{epsilon_{0} A} ) В. ( frac{Q^{2}}{2 epsilon_{0} A} ) c. ( frac{Q^{2}}{epsilon_{0} A} ) D. none of these |
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| 667 | A parallel plate capacitor is filled by a di-electric whose relative permitivity varies with the applied voltage according to the law ( =alpha V ), where ( alpha=1 ) per volt. The same (but containing no dielectric) capacitor charged to a voltage ( V=156 ) volt is connected in parallel to the first “non-linear” uncharged capacitor. Determine the final voltage (in volts) ( V_{f} ) across the capacitors. |
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| 668 | Assertion Two charges ( -q ) each are fixed at points ( A ) and ( B . ) When a third charge ( -q ) is moved from ( boldsymbol{A} ) to ( boldsymbol{B} ), electrical potential energy first decreases, then increases. Reason Along the line joining ( A ) and ( B ), the third charge is in stable equilibrium position |
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| 669 | Which of the following is/are non-polar dielectrics? ( mathbf{A} cdot H C L ) B. water c. Benzene D. ( N H_{3} ) |
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| 670 | A parallel plate capacitor is made by placing n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is ( C ) then the resultant capacitance is: A . nc в. ( frac{C}{n} ) ( c cdot(n+1) c ) D. ( (n-1) C ) |
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| 671 | Assertion If a dielectric is placed in external field then field inside dielectric will be less than applied field. Reason Electric field will induce dipole moment opposite to field direction. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 672 | If the capacitance between two successive plates is ( C, ) then the capacitance of the equivalent system between ( A ) and ( B ) is A ( cdot frac{C}{3} ) в. ( 3 C ) c. ( frac{2 C}{3} ) D. ( frac{3 C}{2} ) |
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| 673 | A thin metallic spherical shell contains a charge ( Q ) on its surface. A point charge ( q_{1} ) is placed at the centre of the shell and another charge ( q_{2} ) is placed outside the shell. All the three charges are positive. Then, the force on charge ( boldsymbol{q}_{1} ) is A. Towards left B. Towards right D. zero |
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| 674 | Calculate the capacitance (in farads) of a charged, parallel-plate capacitor. Given the potential difference between the plates is equal to ( X ) volts and the amount of charge on the POSITIVE plate is equal to ( Y ) coulombs. A ( cdot frac{X}{2 Y} ) в. ( frac{Y}{2 X} ) ( c cdot frac{Y}{X} ) D. ( frac{2 Y}{X} ) E ( cdot frac{2 X}{Y} ) |
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| 675 | Two vertical metallic plates carrying equal and opposite charges are kept parallel to each other like a paralle plate capacitor. A small spherical metallic ball is suspended by a long insulated thread such that it hangs freely in the center of the two metallic plates. The ball, which is uncharged, is taken slowly towards the positively charged plate and is made to touch that plate. Then the ball will : A. stick to the positively charged plate B. come back to its original position and will remain there c. oscillate between the two plates touching each plate in turn D. oscillate between the two plates without touch them |
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| 676 | Figure shows three circular arcs, each of radius ( R ) and total change as indicated. The net electric potential at the center of curvature is :- ( A ) в. ( frac{Q}{2 pi epsilon_{0} R} ) с. ( frac{2 Q}{pi epsilon_{0} R} ) D. ( frac{Q}{pi epsilon_{0} R} ) |
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| 677 | Three charges ( Q,+q ) and ( +q ) are placed at the vertices of a right angle triangle (isosceles triangle) as shown. If the net electrostatic potential energy of the configuration is zero, value of ( Q ) is: A ( cdot frac{+q}{2+sqrt{2}} ) B. ( frac{-q}{2+sqrt{2}} ) c. ( frac{+2 q}{2+sqrt{2}} ) D. ( frac{-2 q}{2+sqrt{2}} ) |
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| 678 | Two positive point charges of ( 12 mu C ) and ( 8 mu C ) are ( 10 c m ) apart. The work done in bringing them ( 4 c m ) closer is A . ( 5.8 . J ) B. ( 5.8 e V ) c. ( 13 . J ) D. ( 13 e V ) |
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| 679 | Three concentric spherical shells have radii ( a, b ) and ( c(a<b<c) ) and have surface charge densities ( +boldsymbol{sigma},-boldsymbol{sigma},+boldsymbol{sigma} ) respectively. If ( V_{A}, V_{B} ) and ( V_{C} ) denote the potentials of three shells, then for ( c=a+b, ) we have A. ( V_{C}=V_{B}=V_{A} ) B. ( V_{C}=V_{B} neq V_{A} ) c. ( V_{C} neq V_{B}=V_{A} ) D. ( V_{C} neq V_{B} neq V_{A} ) |
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| 680 | A point charge ( -q ) is carried from a point ( A ) to another point ( B ) on the axis of a charged ring of radius ‘r’ carrying a charge ( +q / ) If the point ( A ) is at ( a ) distance ( frac{4}{3} r ) from the centre of the ring and the point ( mathrm{B} ) is ( frac{3}{4} r ) from the centre but on the opposite side, what is the net work that need to be done for this? ( ^{mathrm{A}} cdot-frac{7}{5} frac{q^{2}}{4 pi varepsilon_{0} r} ) В. ( -frac{1}{5} frac{q^{2}}{4 pi varepsilon_{0} r} ) c. ( frac{q^{2}}{54 pi varepsilon_{0} r} ) D. ( frac{q^{2}}{54 pi varepsilon_{e} r} ) |
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| 681 | The value of the dielectric constant at room temperature ( (25 mathrm{C}, text { or } 77 mathrm{F}) ) for air is A. 1.00059 в. 2.00059 c. 0.0009 D. 0.00059 |
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| 682 | A parallel plate capacitor having plates of area ( mathrm{S} ) and plate separation ( mathrm{d}, ) has capacitance ( C_{1} ) in air. When two dielectrics of different relative permittivities ( left(varepsilon_{1}=2 text { and } varepsilon_{2}=4right) ) are introduced between the two plates as shown in the figure, the capacitance becomes ( C_{2} . ) The ratio ( frac{C_{2}}{C_{1}} ) is A . ( 6 / 5 ) B. ( 5 / 3 ) ( c cdot 7 / 5 ) ( 0.7 / 3 ) |
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| 683 | The conducting sphere of radii ( r_{1} ) and ( r_{2} ) are at the same potential. What is the ratio of their charges? B . ( r_{2}: r_{1} ) C ( cdot r_{1}^{2}: r_{2}^{2} ) D ( cdot r_{2}^{2}: r_{1}^{2} ) |
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| 684 | In a quark model of elemetary particles, a neutron is made of one up quark of charge ( frac{2}{3} e ) and two down quark of charges ( left(-frac{1}{3} eright) . ) If they have a triangle configuration with side length of the order of ( 10^{-15} ) m. The electrostatic potential energy of neutron in ( M e V ) is A. 7.68 B . -5.21 c. -.048 D. 9.34 |
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| 685 | A parallel plate capacitor is charged by a battery and the battery remains connected, a dielectric slab is inserted in the space between the plates. Explain what changes if any, occur in the values of the (i) potential difference between the plates (ii) electric field between the plates (ii) energy stored in the capacitor |
12 |
| 686 | In a parallel plate condenser if the distance between the plates is made half and the dielectric constant is doubled, then the capacity increases by a factor: A. 2 times B. 4 times ( c .8 ) times D. 16 times |
12 |
| 687 | A parallel-plate capacitor has plates of unequal area. The larger plate is connected to the positive terminal of the battery and the smaller plate to its negative terminal. Let ( Q_{+} ) and ( Q_{-} ) be the charges appearing on the positive and negative plates respectively. Calculate the potential difference between the two plates. |
12 |
| 688 | Four charges ( 10^{-8} ;-2 times 10^{-8} ;+3 times 10^{-8} ) and ( 2 times 10^{-8} ) coulombs are placed at the four corners of a square of side ( 1 mathrm{m} ). The potential at the centre of the square is A . zero B. 360volt c. ( 180 v o l t ) D. ( 360 sqrt{2} ) volt |
12 |
| 689 | A network of four ( 10 mu F ) capacitors is connected to a ( 500 V ) supply, as shown in fig. Determine (a) the equivalent capacitance of the network and (b) the charge on each capacitor.(Note, the charge on a capacitor is the charge on the place with higher potential, equal and opposite to the charge on the plate with lower potential) |
12 |
| 690 | A capacitor of capacitance ( 10, mathrm{f} ) is charged to a potential of ( 100 mathrm{V} ) Now connecting it in parallel with an uncharged capacitor, the resultant potential difference becomes 40 volt.The capacitance of this capacitor is A ( .2 .5, mathrm{F} ) в. ( 5, ) F ( c .10, F ) D. ( 15, ) F |
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| 691 | Three capacitors ( boldsymbol{C}_{mathbf{1}}=boldsymbol{6} boldsymbol{mu} boldsymbol{F}, boldsymbol{C}_{2}= ) ( 12 mu F ) and ( C_{3}=20 mu F ) are connected to a ( 100 V ) battery, as shown following figure below: Calculate: Charge on each plate of capacitor ( C_{1} ) |
12 |
| 692 | Charges of ( q ) coulomb but of alternately opposite signs are placed along the ( x- ) axis at ( x=1, x=2, x=4, ldots ) and so on. The electric potential at the point ( x=0 ) due to all these charges will be A ( cdot frac{q}{2 pi epsilon_{0}} ) в. ( frac{q}{3 pi epsilon_{0}} ) c. ( frac{2 q}{3 pi epsilon_{0}} ) D. ( frac{q}{6 pi epsilon_{0}} ) |
12 |
| 693 | Two materials of dielectric constants ( k_{1} ) and ( k_{2} ) are introduced to fill the space between the two parallel plates of a capacitor as shown in the figure. The capacitance of the capacitor is : A ( cdot frac{A in_{0}left(k_{1}+k_{2}right)}{2 d} ) в. ( frac{2 A in_{0}}{d}left(frac{k_{1} k_{2}}{k_{1}+k_{2}}right) ) c. ( frac{A in_{0}}{d}left(frac{k_{1} k_{2}}{k_{1}+k_{2}}right) ) ( frac{A epsilon_{0}left(k_{1}+k_{2}right)}{2 d k_{2} k} ) |
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| 694 | If ‘Q’ is the quantity of charge, ‘V’ the potential and ‘C’ the capacity of a conductor, they are related as: A. ( C=Q V ) в. ( Q=V C ) c. ( V=C Q ) D. ( C V Q= ) costant |
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| 695 | A parallel plate air capacitor has a initial capacitance ( C . ) If plate separation is slowly increased from ( boldsymbol{d}_{1} ) to ( d_{2} ), then mark the correct statement(s). (Take potential of the capacitor to be constant, i.e. throughout the process it remains connected to battery.) This question has multiple correct options A. Work done by electric force= negative of work done by the external agent. B. Work done by external force ( -int vec{F} . overrightarrow{d x} ), where ( vec{F} ) is the electric force of attraction between the plates at plate separation ( x ) c. work done by electric force ( neq ) negative of work done by external agent D. work done by battery = two times the change in electric potential energy stored in capacitor. |
12 |
| 696 | A parallel plate capacitor is charged by a battery. The battery is disconnected and a dielectric slab is inserted to completely fill the space between the plates. How will (i) its capacitance, (ii) electric field between the plates and (iii) energy stored in the capacitor be affected? Justify your answer giving necessary mathematical expressions for each case. |
12 |
| 697 | If two similarly charged particles are brought near one another, the potential energy of the system will: ( A ). increase B. decrease c. remains the same D. equal to the K.E. |
12 |
| 698 | In the rectangle shown below, the two corners have charges ( q_{1}=-5 mu C ) and ( q_{2}=+2.0 mu C . ) The work in moving a charge ( +3.0 mu C ) from ( B ) to ( A ) is: |
12 |
| 699 | 言 | 12 |
| 700 | The capacitance ( C_{A B} ) in the given network is: ( mathbf{A} cdot 7 mu F ) B. ( frac{50}{7} mu F ) ( mathbf{c} .7 .5 mu F ) D. ( frac{7}{50} mu F ) |
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| 701 | Two plates (area ( =5 ) ) charged to ( +q_{1} ) and ( +q_{2}left(q_{2}<q_{1}right) ) are brought closer to form a capacitor of capacitance ( C ). The potential difference across the plates is A ( cdot frac{q_{1}-q_{2}}{2 C} ) в. ( frac{q_{1}-q_{2}}{C} ) c. ( frac{q_{1}-q_{2}}{4 C} ) D. ( frac{2left(q_{1}-q_{2}right)}{C} ) |
12 |
| 702 | Six point charges are kept at the vertices of a regular hexagon of side ( boldsymbol{L} ) and centre ( O ), as shown in the figure. Given that ( K=frac{1}{4 pi epsilon_{0}} frac{q}{L^{2}}, ) which of the following statement(s) is(are) correct? This question has multiple correct options A. The electric field at ( O ) is ( 6 K ) along ( O D ) B. The potential at ( O ) is zero c. The potential at all points on the line ( P R ) is same D. The potential at all points on the line ( S T ) is same |
12 |
| 703 | The energy stored in magnetic field produced by a metal sphere is 4.5 J. If the sphere contains ( 4 mu C ) charge, its radius will be : ( left[text { Take }: frac{1}{4 pi epsilon_{0}}=9 times 10^{9} N-m^{2} / C^{2}right] ) A. 32 mm B. ( 16 mathrm{mm} ) c. ( 20 mathrm{mm} ) D. 28 mm |
12 |
| 704 | Assertion Physically, if a dielectric with a high value of ( mathrm{k} ) is placed in an electric field, the electric field will be greatly reduced inside. Reason Dielectrics are very useful in modern electronics as it is possible to to precisely control their permittivity by doping them with other types of materials. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 705 | Pick up the correct statement A. Charge on surface of inner sphere is non-uniformly distributed B. Charge on inner surface of outer shell is non-uniformly distributed C. Charge on outer surface of outer shell is nonuniformly distributed D. All the above statements are false |
12 |
| 706 | At a point in space, the electric field points toward north. In the region surrounding this point, the rate of change of potential will be zero along A. north B. south c. north-south D. east-west |
12 |
| 707 | A parallel-plate air capacitor is connected to a battery. The quantities charge, voltage, electric field and energy associated with this capacitor are given by ( Q_{0}, V_{0}, E_{0} ) and ( U_{0} ) respectively. ( A ) dielectric slab is now introduced to fill the space between the plates with battery still in connection. The corresponding quantities now given by Q, ( V ), E and ( U ) are related with previous ones as: This question has multiple correct options A. ( V>V_{0} ) в. ( U>U_{0} ) c. ( Q>Q_{0} ) D. ( E>E_{0} ) |
12 |
| 708 | A hollow charged conductor has a tiny hole cut into its surface. Show that the electric field in the hole is ( left(sigma / 2 epsilon_{0}right) hat{n} ) where ( hat{boldsymbol{n}} ) is the unit vector in the outward normal direction, and ( sigma ) is the surface charge density near the hole. |
12 |
| 709 | ( A, B ) and ( C ) are three large, paralle conducting plates, placed horizontally ( A ) and ( C ) are rigidly fixed and earthed. ( B ) is given some charge. Under electrostatic and gravitational forces, ( boldsymbol{B} ) may be : This question has multiple correct options A. in equilibrium midway between ( A ) and ( C ) B. in equilibrium if it is closer to ( A ) than to ( C ) c. in equilibrium if it is closer to ( C ) than to ( A ) D. ( B ) can never be in stable equilibrium |
12 |
| 710 | Two metal spheres of radii a and b are connected by a thin wire. Their separation is very large compared to their dimensions. The capacitance of this system is? ( mathbf{A} cdot 4 pi varepsilon_{0}(a b) ) В . ( 2 pi varepsilon_{0}(a+b) ) C ( .4 pi varepsilon_{0}(a+b) ) D. ( 4 pi varepsilon_{0}left(frac{a^{2}+b^{2}}{2}right)^{2} ) |
12 |
| 711 | A potential difference of 300 volts is applied to a combination of ( 2.0 mu mathrm{F} ) and ( 8.0 mu mathrm{F} ) capacitors connected in series. The charge on the ( 2.0 mu mathrm{F} ) capacitor is : A . ( 2.4 times 10^{-4} ) coulomb B. ( 4.8 times 10^{-4} ) coulomb c. ( 7.2 times 10^{-4} ) coulomb D. ( 9.6 times 10^{-4} ) coulomb |
12 |
| 712 | The electronic potential ( V ) at a point on the circumference of a thin non- conducting disk of radius r and uniform charge density ( sigma ) is given by equation ( boldsymbol{V}=mathbf{4} boldsymbol{sigma} boldsymbol{r} . ) Which of the following expression correctly represents electrostatic energy store in the electric field of a similar charge disk of radius R? |
12 |
| 713 | What is E in the outer region of the first plate? A ( cdot frac{1}{2} times 10^{-10} N / C ) B . ( 2 times 10^{-10} N / C ) c. ( 0 N / C ) D . ( 5 times 10^{-10} mathrm{N} / mathrm{C} ) |
12 |
| 714 | A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved farther apart by means of insulating handle: This question has multiple correct options A. the charge on the capacitor increases B. the voltage across the plates increases C. the capacitance increases D. the electrostatic energy stored in the capacitor increases |
12 |
| 715 | Identical metal plates are located in air at equal distance ( d ) from one another. The area of each plate is equal to ( A ). If the capacitance of the system between ( P ) and ( Q ) if the plates are interconnected as shown in the figure ( boldsymbol{x} varepsilon_{0} frac{boldsymbol{A}}{boldsymbol{d}} ). Find ( boldsymbol{x} ) |
12 |
| 716 | A charge ( +q ) is fixed at each of the points ( boldsymbol{x}=boldsymbol{x}_{0}, boldsymbol{x}=mathbf{3} boldsymbol{x}_{0}, boldsymbol{x}=mathbf{5} boldsymbol{x}_{0} dots dots, infty ) on the ( x ) -axis and charge ( -q ) is fixed at each of the points ( boldsymbol{x}=mathbf{3} boldsymbol{x}_{0}, boldsymbol{x}= ) ( mathbf{4} boldsymbol{x}_{0}, boldsymbol{x}=boldsymbol{6} boldsymbol{x}_{0}, ldots ldots, infty . ) Here, ( boldsymbol{x}_{0} ) is a positive quantity. Take the electric potential at a point due to charge ( Q ) at a distance ( r ) from it to be ( frac{Q}{4 pi varepsilon_{0} r} . ) Then the potential at origin due to the above system of charges is: A . zero B. infinity c. ( frac{q}{8 pi varepsilon_{0} x_{0} text { In2 }} ) D. ( frac{q operatorname{In} 2}{4 pi varepsilon_{0} x_{0}} ) |
12 |
| 717 | Two identical plane metallic surface ( boldsymbol{A} ) and ( B ) parallel to each other in air separated by a distance of 1 cm let surface ( A ) as given a position potential of ( 10 mathrm{V} ) and surface ( B ) is earthed. |
12 |
| 718 | A charge ( q_{1}=2 mu C ) is located at the origin and a charge ( boldsymbol{q}_{2}=-boldsymbol{6} boldsymbol{mu} boldsymbol{C} ) is located at ( (0,3 m) . ) Find the total electric potential due to the charges at point ( (4 m, 0) ) ( mathbf{A} cdot-6.29 e V ) В. ( -6.29 m V ) ( mathbf{c} .-6.29 M V ) D. – ( 6.29 V ) |
12 |
| 719 | A regular hexagon of side ( 10 mathrm{cm} ) has a charge ( 5 mu C ) at each of its vertices. Calculate the potential at the centre of the hexagon. |
12 |
| 720 | (a) Explain why, for a charge configuration, the equipotential surface through a point is normal to the electric field at that point? Draw a sketch of equipotential surfaces |
12 |
| 721 | Obtain the formula for the capacitance of a parallel plate capacitor. |
12 |
| 722 | Assertion Positive charge always moves from a higher potential point to lower potential point Reason Electric potential is a vector quantity A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
12 |
| 723 | If you have several ( 2.0 mu F ) capacitors, each capable of withstanding 200 volts without breakdown how would you assemble a combination having minimum number of capacitors and of given equivalent capacitance which capable of withstanding 1000 volts ( (A) 0.40 mu F ) (B) ( 1.2 mu F, ) capable of withstanding ( mathbf{1 0 0 0} ) volts. |
12 |
| 724 | Which graph best illustrates the electric potential along the ( x ) axis, from ( x=-a operatorname{tox}=a ? ) ( A ) B. I c. ॥॥ D. IV |
12 |
| 725 | Fig shows some of the equipotential surfaces of the magnetic scalar potential The magnetic field ( B ) at a point in the region is: A ( cdot 2 times 10^{-3} T ) B . ( 4 times 10^{-4} T ) c. ( 2 times 10^{-4} T ) D. ( 4 times 10^{-3} T ) |
12 |
| 726 | The potential energy of a proton is ( 3.2 times 10^{-18} J ) at a particular point. The electric potential at this point is: (Given charge on a proton is ( 1.6 times ) ( left.mathbf{1 0}^{-mathbf{1 9}} boldsymbol{C}right) ) A . ( 5 V ) B. ( 10 V ) ( c .20 V ) D. ( 15 V ) |
12 |
| 727 | Electric charge given to the hollow conductors resides A. On the outer surface B. At the centre c. on the inner surface D. Uniformly on the outer as well as on the inner surface |
12 |
| 728 | In the given figure each capacitor is equal to ( 45 mu F ) then the equivalent capacity between ( A ) and ( B ) in the given circuit is: ( mathbf{A} cdot 15 mu F ) в. ( 10 mu F ) c. ( 40 mu F ) D. ( 135 mu F ) |
12 |
| 729 | Initially the spheres ( A ) and ( B ) are at potential ( V_{A} ) and ( V_{B} ) respectively. Now sphere ( mathrm{B} ) is earthed by closing the switch. The potential of ( A ) will now become: ( A ) B. ( V_{A} ) ( mathbf{c} cdot V_{A}-V_{B} ) D. ( V_{B} ) |
12 |
| 730 | The electric field at a distance ( 2 mathrm{cm} ) from the centre of a hollow spherical conducting shell of radius ( 4 mathrm{cm} ) having a charge of ( 2 times 10^{-3} mathrm{C} ) on its surface is : This question has multiple correct options A . ( 1.1 times 10^{10} V / m ) B . ( 4.5 times 10^{-10} V / m ) C ( .4 .5 times 10^{10} V / m ) D. zero |
12 |
| 731 | If the capacity of a spherical conductor is 1 picofarad, then its diameter would be A ( cdot 1.8 times 10^{-3} mathrm{m} ) B . ( 18 times 10^{-3} m ) c. ( 1.8 times 10^{-5} m ) D. ( 18 times 10^{-5} m ) |
12 |
| 732 | A plane electromagnetic wave in a non magnetic dielectric medium is given by ( overline{boldsymbol{E}}=overline{boldsymbol{E}}_{0}left(mathbf{4} times mathbf{1 0}^{-mathbf{7}} times-mathbf{5 0} boldsymbol{t}right) ) with distance being in meter and time in seconds. The dielectric constant of the medium is: A . 2.4 в. 5.8 ( c cdot 8.2 ) D. 4.8 |
12 |
| 733 | The potential in certain region is given as ( V=2 x^{2}, ) then the charge density of that region is A ( cdot-frac{4 x}{varepsilon_{0}} ) в. ( -frac{4}{varepsilon_{0}} ) ( mathbf{c} .-4 varepsilon_{0} ) D. ( -2 varepsilon_{0} ) |
12 |
| 734 | A body of ( 2 g ) carrying a charge of ( 0.1 times ) ( 10^{-6} C ) starts from rest from the positive plate and moves to the negative plate of a parallel plate condenser connected to a voltage supply of ( 30 k V ). The final velocity is: A ( cdot sqrt{3} m s^{-1} ) B. ( frac{sqrt{3}}{12} m s^{-1} ) c. ( frac{1}{sqrt{2}} m s^{-1} ) D. zero |
12 |
| 735 | In the arrangement shown in figure, dielectric constant ( k_{1}=2 ) and ( K_{2}=3 . ) If the capacitance across ( mathrm{P} ) and ( mathrm{Q} ) are ( C_{1} ) and ( C_{2} ) respectively, then ( frac{C_{1}}{C_{2}} ) will be (the gaps shown are negligible) A . 1: B. 2: ( c .9: 5 ) D. 25: 24 |
12 |
| 736 | Consider the situation shown in the figure. The capacitor A has a charge q on it whereas ( mathrm{B} ) is uncharged. Find the charge appearing on the capacitor ( mathrm{B} ) a long time after the switch is closed A. zero B. ( q / 2 ) ( c cdot q ) D. ( 2 q ) |
12 |
| 737 | The net charge on a condenser is : A . infinity B. ( 9 / 2 ) ( c cdot 29 ) D. zero |
12 |
| 738 | Rank the following points from greatest to least Electric field. ( mathbf{A} cdot 1>2>3 ) B. ( 3>1>2 ) c. ( 3=2>1 ) D. ( 1=2=3 ) |
12 |
| 739 | A capacitor of ( 10 mu F ) capacitance is charged by a ( 12 V ) battery. Now the space between the plates of capacitors is filled with a dielectric of dielectric constant ( K=3 ) and again it is charged. The magnitude of the charge is : A. ( 120 mu C ) в. ( 240 mu C ) c. ( 360 mu C ) D. ( 480 mu C ) |
12 |
| 740 | Two uniformly large parallel thin plates having charge densities ( +sigma ) and ( -sigma ) are kept in the ( X Z ) -plane at distance ( d ) apart. Sketch an equipotential surface due to electric field between the plates. If a particle of mass ( m ) and charge ( -q ) remains stationary between the plates. What is the magnitude and direction of this field? |
12 |
| 741 | Calculate the charge on the capacitor in coulombs if a 20 -F capacitor has a ( 30-v ) potential difference across it. A. ( 6.7 times 10^{-7} mathrm{c} ) В. ( 6.0 times 10^{-4} mathrm{C} ) ( c cdot 1.5 c ) D. ( 6.0 times 10^{2} mathrm{C} ) E . ( 1.5 times 10^{6} mathrm{C} ) |
12 |
| 742 | Two charges ( q ) and ( -q ) are kept apart. Then at any point on the perpendicular bisector of line joining the two charges: A. the electric field strength is zero B. the electric potential is zero c. both electric potential and electric field strength are zero D. both electric potential and electric field strength are non-zero |
12 |
| 743 | A non-conducting sphere has a total charge Q uniformly distributed throughout its volume. the centre of the sphere is at origin and its radius is ( mathrm{R} ) let ( U_{1} ) be the electrostatic potential energy in the region inside the sphere and ( U_{2} ) be the electrostatic potential energy in another imaginary spherical shell, having inner radius ( R ) and outer radius infinity, centred at origin. select the correct alternative(s) ( ^{mathrm{A}} cdot U_{1}=frac{Q^{2}}{8 pi varepsilon_{0} R} ) в. ( U_{2}=frac{Q^{2}}{8 pi varepsilon_{0} R} ) c. ( U_{1}+U_{2}=frac{3}{5} times frac{Q^{2}}{4 pi varepsilon_{0} R} ) D. ( U_{1}=frac{3 Q^{2}}{20 pi varepsilon_{0} R} ) |
12 |
| 744 | Two identical metal plates are given positive charge ( Q_{1} ) and ( Q_{2}left(<Q_{1}right) ) respectively. If they are now brought close together to form a parallel plate capacitor with capacitance ( C, ) the potential difference between them is ( mathbf{A} cdotleft(Q_{1}+Q_{2}right) / 2 C ) B ( cdotleft(Q_{1}+Q_{2}right) / C ) c. ( left(Q_{1}-Q_{2}right) / C ) D ( cdotleft(Q_{1}-Q_{2}right) /(2 C) ) |
12 |
| 745 | Three condensers each of capacitance 2 ( F, ) are connected in series. The resultant capacitance will be : ( A cdot 6 F ) B. 5 ( c cdot 2 / 3 F ) D. 3/2 |
12 |
| 746 | Define linear charge density. Mention its ( S I ) unit. | 12 |
| 747 | n this diagram, the potential difference ( A ) and ( B ) is ( 60 V . ) The potential difference across ( 6 mu F ) capacitor is: ( 4.4 V ) 3. ( 10 V ) ( c .5 V ) ( 20 V ) |
12 |
| 748 | In electroplating, the metal to be used for coating is made the A. Cathode (negative electrode) B. Anode(positive electrode) c. cathode(positive electrode) D. Anode(negative electrode) |
12 |
| 749 | There are six plates of equal are ( A ) and separation between the plates is ( d(d<<A) ) are arranged as shown in figure. The equivalent capacitance between points 2 and ( 5, ) is ( alpha frac{varepsilon_{0} A}{d} . ) Then find the value of ( boldsymbol{alpha} ) |
12 |
| 750 | A charge ( 10 n C ) is situated in a medium of relative permittivity 10. The potential due to this charge at a distance of ( 0.1 m ) is : ( mathbf{A} cdot 900 V ) в. ( 90 V ) ( c .9 V ) D. ( 0.09 V ) |
12 |
| 751 | An equipotential surface is that surface A. on which each and every point has the same potential B. which has negative potential C . which has positive potential D. which has zero potential |
12 |
| 752 | In the circuit shown, the potential difference across the ( 3 mu F ) capacitor is ( mathrm{V}, ) and the equivalent capacitance between ( A ) and ( B ) is ( C_{A B} ) This question has multiple correct options |
12 |
| 753 | A conducting shell ( S_{1} ) having a charge ( Q ) is surrounded by an uncharged concentric conducting spherical shell ( S_{2} ). Let the potential difference between ( S_{1} ) and that ( S_{2} ) be ( V ). If the shell ( S_{2} ) is now given a charge ( -3 Q, ) the new potential difference between the same two shells is : ( A cdot 1 v ) B. 2 ( c cdot 4 v ) D. -2 v |
12 |
| 754 | On changing a capacitor with charge ( mathrm{Q} ) stored energy is W. If charge is doubled then stored energy will be:- A ( .2 W ) в. ( 4 W ) c. ( 8 W ) D. ( frac{1}{2} W ) |
12 |
| 755 | Mark the correct statment: A. An electron and a proton when released from rest in a uniform electric field experience the same force and the same acceleration B. Two equipotential surfaces may intersect. C. A solid conducting sphere holds more charge than a hollow conducting sphere of the same radius. D. No work is done in taking a positive charge from one point to another inside a negatively charged metallic sphere. |
12 |
| 756 | The capacity of a parallel plate condenser is ( 10 mu F ) without the dielectric. Material with a dielectric constant of 2 is used to fill half- thickness between the plates. The new capacitance is ( mu F ) A . 10 B . 20 c. 15 D. 13.33 |
12 |
| 757 | State whether the given statement is True or False: A small isolated conductor has a large positive charge. The electric field inside this conductor will be zero. A. True B. False |
12 |
| 758 | The electric potential at 0 is : A ( cdot frac{sqrt{2} q}{pi varepsilon_{0} a} ) В. ( frac{sqrt{3} q}{pi varepsilon_{0} a} ) c. ( frac{q}{pi varepsilon_{0} a} ) D. zero |
12 |
| 759 | Two parallel plates have equal and opposite charge. When the space between them is evacuated. the electric field between the plates ( 2 times 10^{5} V / m ) When the space is filed with dielectric the electric field becomes ( 10^{5} V / m ) The dielectric constant of he dielectric material is A . 2 B. 4 c. 5 D. 9 |
12 |
| 760 | uniformly charged in such a way that the potential difference between them is ( V_{2}-V_{1}=120 V . ) (i.e. plate 2 is at a higher potential). The plates are separated by ( boldsymbol{d}=mathbf{0 . 1 m} ) and can be treated as infinitely large. An electron is released from rest on the inner surface of plate ( 1 . ) What is its speed when it hits plate ( 2 ?left(e=1.6 times 10^{-19} C, m_{e}=right. ) ( left.9.11 times 10^{-31} k gright) ) ( mathbf{A} cdot 32 times 10^{-19} mathrm{m} / mathrm{s} ) B . ( 6.49 times 10^{6} mathrm{m} / mathrm{s} ) C ( .7 .02 times 10^{12} mathrm{m} / mathrm{s} ) D. ( 1.87 times 10^{6} mathrm{m} / mathrm{s} ) |
12 |
| 761 | What is the shape of the equipotential surface for the line charge? A. Sphere B. Cylinder c. It will depend upon the type of charge D. can’t say |
12 |
| 762 | Show that the effective capacitance, ( C ) of a series combination, of three capacitors, ( C_{1}, C_{2} ) and ( C_{3} ) is given by ( boldsymbol{C}=frac{C_{1} C_{2} C_{3}}{left(C_{1} C_{2}+C_{2} C_{3}+C_{3} C_{1}right)} ) |
12 |
| 763 | The electric field in the dielectric slab is: A ( cdot frac{V}{K d} ) B. ( frac{K V}{d} ) c. ( frac{V}{d} ) D. ( frac{K V}{t} ) |
12 |
| 764 | The electric energy density between the plates of charged condenser is A ( cdot q / 2 varepsilon_{0} A^{2} ) В ( cdot q / 2 varepsilon_{0} A ) ( mathbf{c} cdot q^{2} /left(2 varepsilon_{0} A^{2}right) ) D. none of these |
12 |
| 765 | An insulated charged conducting sphere of radius ( 5 mathrm{cm} ) has a potential of ( 10 mathrm{V} ) at the surface. What is the potential at centre? A . ( 10 V ) в. zero c. same as that at ( 5 mathrm{cm} ) from the surface D. same as that at ( 25 mathrm{cm} ) from the surface |
12 |
| 766 | A charged particle ( q ) is shot from a large distance towards another charged particle ( Q ) which is fixed, with a speed ( v ) t approaches ( Q ) up to a closest distance ( r ) and then returns. If ( q ) were given a speed ( 2 v, ) the distance of approach would be ( A ) B. ( 2 r ) c. ( r / 2 ) D. ( r / 4 ) |
12 |
| 767 | Identical charges -q each are placed at 8 corners of a cube of each side ( b ) Electrostatic potential energy of a charge +q which is placed at the centre of cube will be : ( ^{mathbf{A}} cdot frac{-4 sqrt{2} q^{2}}{pi epsilon_{0} b} ) B. ( frac{-8 sqrt{3} q^{2}}{pi epsilon_{6} b} ) ( ^{mathrm{c}} cdot frac{-4 q^{2}}{sqrt{3} pi epsilon_{0} b} ) D. ( frac{-8 sqrt{2} q^{2}}{pi epsilon_{0} b} ) |
12 |
| 768 | A uniformly charged solid sphere of radius R has potential ( V_{0} ) (measured with respect to ( infty ) ) on its surface. For this sphere the equipotential surfaces with potentials ( frac{3 V_{0}}{2}, frac{5 V_{0}}{4}, frac{3 V_{0}}{4} ) and ( frac{V_{0}}{4} ) have radius ( boldsymbol{R}_{1}, boldsymbol{R}_{2}, boldsymbol{R}_{3} ) and ( boldsymbol{R}_{4} ) respectively. Then : A ( . R_{1}=0 ) and ( R_{2}>left(R_{4}-R_{3}right) ) B . ( R_{1} neq 0 ) and ( left(R_{2}-R_{1}right)>left(R_{4}-R_{3}right) ) ( mathbf{c} cdot 2 R<R_{4} ) D. None of the above |
12 |
| 769 | Define electric potential. | 12 |
| 770 | A nucleus has charged of +50 e ( A ) proton is located at a distance of ( 10 mathrm{m} ) The potential at this point in volt will be- |
12 |
| 771 | Pis a point on an equipotential surface S. The field at Pis E. This question has multiple correct options A. E must be perpendicular to s in all cases B. E will be perpendicular to S only if S is a plane surface. C. E cannot have a component along a tangent to S. D. E may have a nonzero component along a tangent to if ( mathrm{S} ) is a curved surface. |
12 |
| 772 | For case III what is the direction of the electric force exerted by the field on the ( +1 mu C ) charged object when at ( A ) and when at ( B ? ) A. left at ( A ) and left at ( B ) B. right at ( A ) and right at ( B ) C. left at A and right at B D. right at A and left at B E. no electric force at either positions |
12 |
| 773 | ( frac{E}{L} ) | 12 |
| 774 | Calculate the effective capacitance ( operatorname{across} X Y ) ( A cdot frac{5}{2} C ) ( B cdot frac{3}{E} C ) ( c cdot frac{5}{2} c ) D. ( C ) |
12 |
| 775 | A hollow sphere of radius 5 cm is charged such that the potential on its surface is ( 10 mathrm{V} ). The potential at the center of the sphere will be: ( mathbf{A} cdot 0 V ) B. ( 10 V ) C. same as at a point ( 5 mathrm{cm} ) away from the surface D. same as at point ( 25 mathrm{cm} ) away from the center |
12 |
| 776 | A battery of ( 100 mathrm{V} ) is connected to series combination of two identical parallel- plate condensers. If dielectric of constant 4 is slipped between the plates of second condenser, then the potential difference on the condensers will respectively become: ( A cdot 80 vee, 20 v ) B. ( 75 vee, 25 mathrm{V} ) c. ( 50 v ), ( 80 v ) D. 20 V, 80 V |
12 |
| 777 | A parallel plate air capacitor has capacity ( ^{prime} C^{prime} ) farad, potential ( ^{prime} V^{prime} ) volt and energy’ ( E^{prime} ) joule. When the gap between the plates is completely filled with dielectric. ( A . ) Both ( V ) and ( E ) increase B. Both ( V ) and ( E ) decrease c. ( V ) decreases, ( E ) increases D. ( V ) increases, ( E ) decreases |
12 |
| 778 | Three capacitance of capacity ( 10 mu F, 5 mu F ) are connected in parallel. The total capacity will be : ( mathbf{A} cdot 10 mu F ) в. ( 5 mu F ) ( mathbf{c} cdot 20 mu F ) D. None of the above |
12 |
| 779 | Three capacitors of capacitance 1.0,2.0 and ( 5.0 mu F ) are connected in series to a ( 10 V ) source. The potential difference across the ( 2.0 mu F ) capacitor is A ( cdot frac{100}{17} ) в. ( frac{20}{17} v ) c. ( frac{50}{17} v ) D. ( 10 V ) |
12 |
| 780 | A parallel plate capacitor is first charged and then isolated, and a dielectric slab is introduced between the plates. The quantity that remains unchanged is: A. charge ( Q ) B. potential ( V ) c. capacity ( C ) D. energy ( U ) |
12 |
| 781 | Four point charges ( -Q,-q, 2 q ) and ( 2 Q ) are placed, one at each corner of the square. The relation between ( Q ) and ( q ) for which the potential at the centre of the square is zero is A. ( Q=-q ) в. ( Q=-frac{1}{q} ) c. ( Q=q ) ( mathrm{D} cdot Q=frac{1}{q} ) |
12 |
| 782 | Two equal charges q of opposite sign are separated by a small distance ‘2l.’ The electric potential at a point on the perpendicular bisector of the line joining the two charges at a distance r is: ( mathbf{A} cdot frac{1}{4 pi varepsilon_{0}} frac{q}{r} ) B. ( frac{1}{4 pi varepsilon_{0}} frac{2 q}{r} ) c. zero D. ( frac{1}{4 pi varepsilon_{0}} frac{2 q}{r^{2}} ) |
12 |
| 783 | What is an equipotential surface? | 12 |
| 784 | What happens when a nonpolar material is subjected to external electric field. |
12 |
| 785 | In the following figure potential difference between ( A ) and ( B ) is ( A ) B. 5 volt ( c cdot 10 ) volt D. 15 volt |
12 |
| 786 | A large conducting plane has surface charge density ( 10^{-2} C / m^{2} . ) Find the electrostatic energy stored in a cubical volume of side ( 1 mathrm{cm} ) in the front plane. A. 1.4 B. ( 2.8 J ) c. ( 5.6 J ) D. none of these |
12 |
| 787 | The charge that will flow to earth when only switch ( S_{1} ) is connected to earth is : A . ( -(Q / 2) ) B. ( (Q / 2) ) c. ( 3 Q / 4 ) D. ( -Q ) |
12 |
| 788 | A solid conducting sphere of radius a having a charge ( q ) is surrounded by a concentric conducting spherical shell of inner radius ( 2 a ) and outer radius ( 3 a ) as shown in figure. Find the amount of heat produced when switch is closed ( left(boldsymbol{K}=frac{mathbf{1}}{mathbf{4} boldsymbol{pi} varepsilon_{0}}right) ) ( ^{mathrm{A}} cdot_{K}=frac{k q^{2}}{2 a} ) в. ( _{K}=frac{k q^{2}}{3 a} ) ( ^{mathrm{c}} cdot_{K}=frac{k q^{2}}{4 a} ) D. ( _{K}=frac{k q^{2}}{6 a} ) |
12 |
| 789 | A potential difference is applied across the ends of a metallic wire. If the potential difference is doubled, the drift velocity will A. Be doubled B. Be halved c. Be quadrupled D. Remain unchanged |
12 |
| 790 | The voltage can be increased, but electric breakdown will occur if the electric field inside the capacitor becomes too large. The capacity can be increased by A. expanding the electrode areas B. reducing the gap between the electrodes c. expanding the gap between the electrodes D. Both A and B |
12 |
| 791 | A parallel plate capacitor with air between the plates is charged to a potential difference of ( 500 V ) and then insulated. A plastic plate is inserted between the plates filling the whole gap. The potential difference between the plates now becomes ( 75 V . ) The dielectric constant of plastic is : A ( .10 / 3 ) B. 5 ( c cdot 20 / 3 ) D. 10 |
12 |
| 792 | The equivalent capacitance ( C_{A B} ) of the circuit shown in the figure is: ( A cdot frac{5}{1} ) ( B cdot frac{4}{E} C ) ( c cdot 2 C ) D. ( C ) |
12 |
| 793 | The equation of an equipotential line in an electric field is ( y=2 x, ) then the electric field strenght vector at (1,2) may be: A ( .4 hat{i}+3 hat{j} ) B. ( 4 hat{i}+8 hat{j} ) c. ( 8 hat{i}+4 hat{j} ) D. ( -8 hat{i}+4 hat{j} ) |
12 |
| 794 | The displacement of charge ( q ) in the electric field ( overrightarrow{boldsymbol{E}}=boldsymbol{e}_{1} hat{boldsymbol{i}}+boldsymbol{e}_{2} hat{boldsymbol{j}}+boldsymbol{e}_{3} hat{boldsymbol{j}} ) is ( overrightarrow{boldsymbol{r}}= ) ( a hat{i}+b hat{j} . ) The work done is A ( cdot Qleft(e_{1}+e_{2}right) sqrt{a^{2}+b^{2}} ) в. ( Q(a+b) sqrt{e_{1}^{2}+e_{2}^{2}} ) c. ( Qleft(a e_{1}+b e_{2}right) ) D. ( Q sqrt{left(a e_{1}right)^{2}+left(b e_{2}right)^{2}} ) |
12 |
| 795 | Two point charges ( -q ) and ( +q ) are located at points ( (0,0,-a) ) and ( (0,0, a) ) respectively. The electric potential at point ( (0,0, z) ) is : A ( cdot frac{q a}{4 pi varepsilon_{0} z^{2}} ) в. ( frac{q}{4 pi varepsilon_{0} a} ) c. ( frac{2 q a}{4 pi varepsilon_{0}left(z^{2}-a^{2}right)} ) D. ( frac{2 q a}{4 pi varepsilon_{0}left(z^{2}+a^{2}right)} ) |
12 |
| 796 | Suppose Earth has a volume ‘V’ and surface area ‘A’; then its becomes a large capacitor having the value of capacitance as A ( cdot 12 pi in_{0} frac{V}{A} ) в. ( _{4 pi in_{0}} frac{V}{A} ) c. ( _{4 pi in_{0}} frac{A}{V} ) D. ( _{12 pi in_{0}} frac{A}{V} ) |
12 |
| 797 | The electric field at any point ( (x, y, z) ) is ( mathbf{A} cdot(8 x-3) hat{i} ) B . ( -(8 x-3) ) c. ( -8 x hat{i} ) D. ( 8 x hat{i} ) |
12 |
| 798 | A 12 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor? |
12 |
| 799 | Two concentric shells of radii ( d ) and ( 2 d ) respectively are placed far away from a parallel plate capacitor. Each plate of the capacitor is a square of side ( d ) and separation between the plates is ( d / 4 pi ) The charge on the plates are ( q ) and ( -q ) Then the keys ( k_{1} ) and ( k_{2} ) are closed, find the charges on the shells and electric potential energy left in the parallel plate capacitor in equilibrium. |
12 |
| 800 | Two identical charges, ( 5 mu C ), each are fixed at a distance ( 8 mathrm{cm} ) and a charged particle of mass ( 9 times 10^{-6} k g ) and charge ( -10 mu C ) is placed at a distance ( 5 mathrm{cm} ) from each of them and is released. Find the speed of the particle when it is nearest to the two charges. |
12 |
| 801 | Two point charges ( Q ) and ( -Q / 4 ) placed along the ( x ) -axis are separated by a distance ( r . ) Take ( -Q / 4 ) as origin and it is placed at the right of ( Q . ) Then the potential is zero. ( mathbf{A} cdot ) at ( x=r / 3 ) only B. at ( x=-r / 5 ) only C. both at ( x=r / 3 ) and at ( x=-r / 5 ) D. there exist two points on the axis where the electric field is zero |
12 |
| 802 | The electric volt is a measure of electrical potential. Identify which of the following can be defined as a volt. A. Opposition to electrical motion B. Number of particles in motion c. work per unit charge D. Field strength per unit of force E. Electrostatic discharge |
12 |
| 803 | In a conductor, a point ( P ) is at a higher potential than another point ( Q . ) In which direction do the electrons move? |
12 |
| 804 | Find the charge in steady state of the capacitor. ( A cdot 10 ) nC B. 20 nC ( c .30 mathrm{nc} ) D. 40 nc E. None of the above |
12 |
| 805 | If ( mathrm{E} ) is the electric field intensity of an electrostatic field, then the electrostatic energy density is proportional to: ( A cdot E ) B . ( E^{2} ) c. ( 1 / E^{2} ) D. ( E^{3} ) |
12 |
| 806 | A metallic sphere is placed in a uniform electric field. Which one of paths ( a, b, c ) and ( d ) shown in the figure will be followed by the field lines and why? |
12 |
| 807 | Q Type your question i. If electrical resistivity of metal ( boldsymbol{X} ) is lower than that of metal ( Y ), it means metal ( X ) is better conductor of electricity than metal ( Y ) ii. If a wire of resistance ( 8 Omega ) is doubled on itself, the resistance of the new wire will be ( 2 Omega ) iii. The coils of electric toasters and irons are made of an alloy rather than a pure metal because resistivity of the alloy is higher than that of its constituent metals. iv. If a conductor of length ( 65 mathrm{cm} ) has a resistance of ( 4 Omega, ) the same conductor of length ( 260 mathrm{cm} ) will have the resistance of ( 16 Omega ) v. The maximum amount of current that can pass through a conductor is ( 440 A ) A. i, iii and v B. i, ii, iii and iv c. iii, iv and ( v ) D. iii and iv only |
12 |
| 808 | The equivalent capacitance between the terminals ( X ) and ( Y ) in the figure shown will be – A ( .100 p F ) в. ( 200 p F ) c. ( 300 p F ) D. ( 400 p F ) |
12 |
| 809 | What is the shape of the equipotential surface for the line charge? A. Sphere B. cylinder c. will depend upon the type of charge. D. can’t say. |
12 |
| 810 | What is the surface charge density on the (i) inner surface (ii) outer surface of the shell |
12 |
| 811 | Dielectric constant for a metal is: A . zero B. infinite ( c cdot 1 ) D. 10 |
12 |
| 812 | The capacity of a parallel plate condenser consisting of two plates each of ( 10 mathrm{cm}^{2} ) separated by a distance of ( 2 mathrm{mm} ) is: (Take air as the medium between the plates A ( cdot 8.85 times 10^{-13} F ) В. ( 4.42 times 10^{-12} mathrm{F} ) c. ( 44.25 times 10^{-12} F ) D. ( 88.5 times 10^{-13} F ) |
12 |
| 813 | The angle between electric lines of force and equipotential surface is : ( mathbf{A} cdot 0^{circ} ) B . ( 180^{circ} ) ( c cdot 90^{circ} ) ( D cdot 45^{circ} ) |
12 |
| 814 | A capacitor has some dielectric between its plates, and the capacitor is connected to a dc source. The battery is now disconnected and then the dielectric is removed, then A. capacitance will increase B. energy stored will decrease. c. electric field will increase D. Voltage will decrease |
12 |
| 815 | A change of ( 2 x^{-7} C ) moves from the origin to the point (4,4) with co- ordinates measured in meters (see figure). Calculate the work done by the uniform electric field ( boldsymbol{E}=(mathbf{1} . mathbf{0} times ) ( left.10^{4}right) hat{i} N / C ) for each of three paths: (a) (0,0)( rightarrow(4,0) rightarrow(4,4) ) (b) ( (0,0) rightarrow(4,4), ) along the diagonal ( (c)(0,0) rightarrow(0,4) rightarrow(4,4) ) (d) What is the electrostatic potential at point (4,4) relative to the origin? |
12 |
| 816 | Charges are placed on the vertices of a square as shown. Let ( overrightarrow{boldsymbol{E}} ) be the electric field and ( V ) be the potential at the centre. If the charges on ( A ) and ( B ) are interchanged with those on D and ( mathbf{C} ) respectively, then: A ( . vec{E} ) remains unchanged, ( V ) changes B. Both ( vec{E} ) and ( V ) change C ( . vec{E} ) and ( V ) remain unchanged D. ( vec{E} ) changes, ( V ) remains unchanged |
12 |
| 817 | Two fixed charges ( -2 Q ) and ( +Q ) are located at points ( (-3 a, 0) ) and ( (+3 a, 0) ) respectively, Then which of the following statement is correct? A. Points where the electric potential due to the two charges is zero in ( x ) -y plane, lie on a circle of radius 42 and centre (5a, 0) B. Potential is zero at ( x=a ) and ( x=9 a ) c. Both (a) and (b) are wrong D. Both (a) and (b) are correct |
12 |
| 818 | Two identical positive charges are 0.6 meters apart. Which of the following is true about the electric field and potential at the point which is directly in-between the two? A. The electric field and potential both are zero B. The electric field and potential both are positive numbers C. The electric field is a positive number while the potential is zero D. The electric field is zero while the potential is a positive number |
12 |
| 819 | The radius of a hypothetical nucleus (atomic number ( =mathbf{7} 9 ) ) is about ( mathbf{7} times ) ( 10^{-15} mathrm{m} . ) Assuming that charge distribution is uniform, the electric field at distance of ( 3.5 times 10^{-15} ) of the nucleus is : A ( cdot 3 times 10^{20} ) В. ( 1.7 times 10^{21} ) c. ( 3.5 times 10^{20} ) D. ( 3.5 times 10^{21} ) |
12 |
| 820 | Six capacitors each of capacitance of ( 2 mu F ) are connected as shown in the figure. The effective capacitance between ( A ) and ( B ) is ( mathbf{A} cdot 12 mu F ) B. ( -mu F ) ( F F ) ( c .3 mu F ) D. ( 6 mu F ) |
12 |
| 821 | Assertion: Two equipotential surfaces cannot cut each other. Reason: Two equipotential surfaces are |
12 |
| 822 | Three charges ( -q, Q,-q ) are placed at equal distance on a straight line. If the total potential energy of the system is zero, then ( Q: q ) is: A .1: 4 B. -1: 4 c. 1: 2 D. 2: 1 |
12 |
| 823 | A charged parallel plate capacitor of distance (d) has ( U_{0} ) energy. A slab of dielectric constant (K) and thickness (d) is then introduced between the plates of the capacitor. The new energy of the system is given by: A ( . ) к ( U_{0} ) B. ( K^{2} U_{0} ) ( c cdot frac{U_{0}}{K_{0}} ) D. ( frac{U_{0}}{K^{2}} ) |
12 |
| 824 | How much work is required to slowly move a ( 1 mu C ) charge from ( E ) to D? A ( cdot 2 times 10^{-5} J ) B . ( -2 times 10^{-5} J ) C ( cdot 4 times 10^{-5} J ) D. ( -4 times 10^{-5} J ) |
12 |
| 825 | Define the following term. Surface charge density. | 12 |
| 826 | The electric potential inside a conductor: A . is zero B. increases with distance from center c. is constant D. decreases with distance from center |
12 |
| 827 | A lightning conductor is a A. piece of wire with spikes through which current can flow B. sbstance that can be charged by clouds C. metal rod with spikes, ending in a copper plate buried in the ground, fixed to a building to protect it from lightning D. copper plate buried in the ground below a building to protect it from lightning. |
12 |
| 828 | Assertion When a charge is brought near a conductor then a very small value current is established in the conductor Reason since electric field inside the conductor has to be zero so to overcome the electric field of the external charge, internal charge of conductor is collected all accross the surface. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 829 | The top of the atmosphere is about ( 400 k V ) with respect to the surface of earth, corresponding to an electric field that decreases with altitude. Near the surface of earth the field is about ( 100 V m^{-1}, ) but still don’t get an electric shock, as we set out of our houses in to open because (assume the house is free from electric field) A. our body is a perfect insulator B. our body and ground form an equipotential surface c. the original euipotential surfaces of open air remain same D. none of these |
12 |
| 830 | Find the electric potential at an arbitrary point on the ( x ) axis? ( left(V_{o}=frac{boldsymbol{q}}{4 pi epsilon_{o} a}right) ) ( ^{mathrm{A}} cdot V(x)=V_{o}left(frac{1}{left|frac{x}{a}-1right|}-frac{1}{left|frac{x}{a}+1right|}right) ) B. ( V(x)=V_{o}left(frac{1}{left|frac{x}{a}+1right|}-frac{1}{left|frac{x}{a}-1right|}right) ) c. ( V(x)=left(frac{1}{left|frac{x}{a}-1right|}-frac{1}{left|frac{x}{a}+1right|}right) ) D. ( V(x)=left(frac{1}{left|frac{x}{a}+1right|}-frac{1}{left|frac{x}{a}-1right|}right) ) |
12 |
| 831 | Two identical conductors of copper and aluminium are placed in an identical electric field. What is the magnetic of induced charge in the aluminium? A. Less than in copper B. Equal to that in copper c. Greater than in copper D. zero |
12 |
| 832 | If 3 charges are placed at the vertices of equilateral triangle of charge ( ^{prime} boldsymbol{q}^{prime} ) each What is the net potential energy, if the side of equilateral triangle is ( 1 c m ) A. ( frac{1}{4 pi epsilon_{0}} frac{q^{2}}{l} ) B. ( frac{1}{4 pi epsilon_{0}} frac{2 q^{2}}{l} ) c. ( frac{1}{4 pi epsilon_{0}} frac{3 q^{2}}{l} ) D. ( frac{1}{4 pi epsilon_{0}} frac{4 q^{2}}{l} ) |
12 |
| 833 | What is the name of ( varepsilon_{0} ) ? what is the value |
12 |
| 834 | The equivalent capacitance between points ( A ) and ( B ) for the given figure is ( A cdot 1 F ) В. ( 2 F ) ( c .3 F ) 2.4 |
12 |
| 835 | A parallel plate capacitor is connected to a cell. It’s positive plate ( A ) and the negative plate B have charges ( +boldsymbol{Q} ) and ( -Q ) respectively. A third plate ( C ) identical to ( A ) and ( B ) with charge ( +Q ) is now introduced midway between the plates ( A ) and ( B ) parallel to them What is the charge on the inner surface of ( A ) ? A ( cdot Q ) в. ( frac{mathrm{Q}}{2} ) c. ( frac{3 Q}{2} ) D. ( frac{mathrm{Q}}{4} ) |
12 |
| 836 | In a uniform electric field, equipotential surfaces must: This question has multiple correct options A. be plane surfaces B. be normal to the direction of the field C. be spaced such that surfaces having equal differences in potential are separated by equal distances D. have decreasing potentials in the direction of the field |
12 |
| 837 | A hollow metal ball carrying an electric charge produces no electric field at points. A. outside the sphere B. on its surface c. Inside the sphere D. At a distance more than twice |
12 |
| 838 | Which of the following factors do not influence the capacity of a capacitor? A. distance between the plates B. material of the plates c. area of the plates D. curvature of the plates |
12 |
| 839 | Area of each of the conducting plates 1 2,3,4,5 and 6 is ( A . ) The system is kept in air. Find the the capacitance between ( A ) and ( B(1 & 4,2 & 5 text { and } 3 & 6 ) are pairs of parallel plates) A. ( frac{3 varepsilon_{0} A}{d} ) B. ( frac{2}{3} frac{varepsilon_{0} A}{d} ) c. ( frac{3}{2} frac{varepsilon_{0} A}{d} ) D. ( frac{varepsilon_{0} A}{3 d} ) |
12 |
| 840 | A ( 60 p F ) capacitor is fully charged by a ( 20 V ) supply. It is then disconnected from the supply and is connected to another uncharged ( 60 p F ) capacitor in parallel. The electrostatic energy that is lost in this process by the time the charge is redistributed between them is ( (operatorname{in} n J) ) |
12 |
| 841 | Find the potential energy of an electric dipole (length ( 4 mathrm{cm} ) ) each experiences a torque of ( 4 sqrt{3} mathrm{Nm} ) placed in a from electric field angle ( 60^{circ} q=1+n c ) |
12 |
| 842 | When a steady current passes through a cylindrical conductor, is there an electric field inside the conductor? |
12 |
| 843 | A charge of ( +4 mu C ) is kept at a distance of ( 50 mathrm{cm} ) from a charge of ( -6 mu C ). Find the two points where the potential is zero A. Internal point lies at a distance of ( 20 mathrm{cm} ) from ( 4 mu mathrm{C} ) charge and external point lies at a distance of ( 100 mathrm{cm} ) from ( 4 mu C ) charge B. Internal point lies at a distance of ( 30 mathrm{cm} ) from ( 4 mu C C ) charge and external point lies at a distance of ( 100 mathrm{cm} ) from ( 4 mu C ) charge c. Potential is zero only at ( 20 mathrm{cm} ) from ( 4 mu mathrm{C} ) charge between the two charges D. Potential is zero only at ( 20 mathrm{cm} ) from ( -6 mu mathrm{C} ) charge between the two charges |
12 |
| 844 | Three charges, each ( +q, ) are placed at the corners of an isosceles triangle ( A B C ) of sides ( mathrm{BC}, mathrm{AC} ) and ( mathrm{AB} ). D and ( mathrm{E} ) are the midpoints of BC and CA. The work done in taking a charge ( Q ) from ( D ) to ( E ) is: (Given ( B C=A C) ) A ( cdot frac{e q Q}{8 epsilon q} ) B. ( frac{q Q}{4 epsilon_{6} a} ) C. zero D. ( frac{3 q Q}{4 epsilon_{6} a} ) |
12 |
| 845 | An extremely long wire is uniformly charged. An electron is revolving around the wire and making ( 10^{8} ) revolutions per second in an orbit of radius ( 2 mathrm{cm} ). Linear charge density of the wire is nearly? A. ( 50 n C / m ) B. ( 25 n C / m ) c. ( 40 n C / m ) D. ( 12.5 n C / m ) |
12 |
| 846 | ( N ) conducting plares are placed face to face as shown in figure. Distance between any two plates is ( d ). Area of the plates is ( A, frac{A}{2}, frac{A}{4}, frac{A}{8} dots frac{A}{2(n-1)} . ) The equivalent capacitance of the system is |
12 |
| 847 | The work done in carrying a charge a circle of radius with a charge ‘Q’ at the center is: A. ( frac{1}{4 pi epsilon_{0}} cdot frac{q Q}{r} ) в. ( frac{1}{4 pi epsilon_{0}} cdot frac{q Q}{pi r} ) c. ( frac{1}{4 pi epsilon_{0}} cdot frac{q Q}{2 pi r} ) D. zero |
12 |
| 848 | Deduce an expression for the capacitance of a parallel plate capacitor. |
12 |
| 849 | Two point charges ( Q ) and ( -Q / 4 ) are separated by a distance ( x . ) Then: This question has multiple correct options A. potential is zero at a point on the axis which is ( x / 3 ) on the right side of the charge ( -Q / 4 ) B. potential is zero at a point on the axis which is ( x / 5 ) on the left side of the charge ( -Q / 4 ) C. electric field is zero at a point on the axis which is at a distance ( x ) on the right side of the charge ( -Q / 4 ) D. there exist two points on the axis where electric field is zero |
12 |
| 850 | What is the unit of electric potential difference? A. volt B. Coulamb c. Joul D. watt |
12 |
| 851 | toppr Q Type your question close to each other. Is the magnitude of electrostatic force between them exactly given by ( Q_{1} Q_{2} / 4 pi epsilon_{0} r^{2}, ) where ( r ) is the distance between their centres? (b) If Coulomb’s law involved ( 1 / r^{3} ) dependence (instead of ( 1 / r^{2} ) ),would Gauss’ law be still true? (c) A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point? (d) What is the work done by the field of a nucleus in a complete circular orbit of the electron? What if the orbit is elliptical? (e) We know that electric field is discontinuous across the surface of a charged conductor. Is electric potential also discontinuous there? (f) What meaning would you give to the capacitance of a single conductor? (g) Guess a possible reason why water has a much greater dielectric constant ( (=80) ) than say, mica ( (=6) ) |
12 |
| 852 | A capacitor is charged by a cell of emf ( boldsymbol{E} ) and the charging battery is then removed. If an identical capacitor is now inserted in the circuit in parallel with the previous capacitor, the potential difference across the new capacitor is : ( A cdot 2 E ) в. ( E ) c. ( E / 2 ) D. zero |
12 |
| 853 | In given Figure, a charge ( Q ) is fixed. Another charge ( q ) is moved along a circular arc MN of radius r around it, from the point ( mathrm{M} ) to the point ( mathrm{N} ) such that the length of the arc ( M N=l . ) The work done in this process is : A. Zero В. ( frac{1}{4 pi epsilon_{0}} cdot frac{Q q}{r^{2}} l ) c. ( frac{Q q}{2 epsilon_{0} r^{2}} l ) D. ( frac{Q q}{2 pi epsilon_{0} r^{2}} ) |
12 |
| 854 | Calculate the electric potential difference between the outside and the inside cylinders in ( V ) |
12 |
| 855 | The vertical displacement traveled by the proton as it exits the region between the plates is (mass of proton is ( 1.67 times ) ( left.10^{-27} k g .right) ) A ( cdot 1.6 times 10^{-8} mathrm{m} ) B . ( 3.25 times 10^{-8} mathrm{m} ) ( c cdot 5.25 times 10^{-6} m ) D. ( 2.73 times 10^{-6} mathrm{m} ) |
12 |
| 856 | Assertion Net charge given to a conductor resides on its outer surface under electrostatic conditions. Reason Electric field lines do not enter a conductor under electrostatic conditions. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 857 | A spherical capacitor consists of two concentric spherical conductors, held in position by suitable insulating supports (Fig.). Show that the capacitance of a spherical capacitor is given by ( c=frac{4 pi epsilon_{0} r_{1} r_{2}}{r_{1}-r_{2}} ) where ( r_{1} ) and ( r_{2} ) are the radii of outer and inner spheres, respectively. |
12 |
| 858 | The surface density on the copper sphere is ( sigma . ) The electric field strength on the surface of the sphere is: ( A ) B . ( sigma / 2 ) c. ( sigma / 2 varepsilon_{0} ) D. ( sigma / varepsilon_{0} ) |
12 |
| 859 | Q Type your question_ charge of ( +5 q . ) Which diagram best represents the charge distribution on the sphere? ( mathbf{A} ) Solid Conducting Sphere Stand B. Solid Conducting Sphere Stand ( c ) Solid Conducting Sphere Stand D. Solid Conducting Sphere Stand |
12 |
| 860 | Charge ( +q ) placed at point ( A ) is a distance ( 2 L ) apart from ( B ) and ( C ) is the midpoint between A and B. The work done in moving charge ( +mathrm{Q} ) along the semicircle CRD is ( mathbf{A} cdot frac{mathrm{q} Q}{2 pi varepsilon_{mathrm{U}}} ) B. ( frac{9 Q}{6 pi varepsilon_{0}} ) ( mathbf{c} cdot-frac{q Q}{6 pi varepsilon L} ) D. ( frac{q Q}{4 frac{q Q}{4 varepsilon_{0} L}} ) |
12 |
| 861 | apacitor ( (1) so as to fill the gap eeping the battery remainc charge on each capacit ( frac{2 m}{1+(1 / 1 / k)} ) ( frac{omega(10)}{1} ) ( frac{2 omega}{(1+k)} ) ( frac{2 w}{10-k} ) |
12 |
| 862 | What is electrostatic shielding? Mention one application of it. | 12 |
| 863 | Two plates are placed at a separation of ( 2 mathrm{cm} . ) An electron placed at the perryferry of one plate reaches the second plate in 2 microsecond. Calculate the inner charge density of the surface assuming the case of infinite plate. A . ( 0.505 times 10^{-12} mathrm{Cm}^{-2} ) В. ( 0.15 times 10^{-12} mathrm{Cm}^{-2} ) c. ( 1.01 times 10^{-12} mathrm{Cm}^{-2} ) D. ( 0.505 times 10^{-11} mathrm{Cm}^{-2} ) |
12 |
| 864 | The dielectric to be used in a parallelplate capacitor has a dielectric constant of 3.60 and a dielectric strength of ( 1.60 times 10^{7} V / ) m. The capacilnr is to have a capacitance of ( 1.25 times 10^{-9} F ) and must be able to ( u ) withstand a maximum potential difference of 5500 V. The minimum area the plates of the capacitor may have is equal to ( 135 times 10^{-x} m^{2} . ) The value of ( x ) is: |
12 |
| 865 | Nature of equipotential surface for a point charge is: A. Ellipsoid with charge at foci B. Sphere with charge at the center of the sphere C. Sphere with charge on the surface of the sphere D. Plane with charge on the surface |
12 |
| 866 | A capacitor of capacitance ( C ) is charged to a potential difference ( V ) from a cell and then disconnected from it. A charge ( +mathrm{Q} ) is now given to its positive plate. The potential difference across the capacitor is now: A. в. ( v+frac{Q}{C} ) c. ( v+frac{Q}{2 C} ) D. ( V-frac{Q}{C} ), if ( Q<C V ) |
12 |
| 867 | Calculate the amount of work done in moving a charged particle of charge ( q ) through a potential difference of ( V ) A ( cdot frac{q}{V} ) в. ( frac{V}{q} ) c. ( frac{1}{q V} ) D. ( q V ) |
12 |
| 868 | An ideal dipole of dipole moment ( vec{p} ) is placed in front of an uncharged conducting sphere of radius ( R ) as shown A ( cdot ) The potential at point ( A ) is ( frac{K P}{(r-R)^{2}} ) B. The potential at point A is ( frac{K P}{r^{2}} ) C the potential due to dipole at point B is ( frac{K P}{(r+R)^{2}} ) D. The potential due to dipole at point B is ( frac{K}{r^{2}} ) |
12 |
| 869 | The capacitance between adjacent plates shown in Fig ( 20.95(a) ) is 50 nF. ( A 1 mu C ) charge is placed on the middle plate. Find the charge on the outer surface of upper plate and the potential difference between upper and middle plates: A. ( 0.5 mu C, 10 V ) B. ( 1 mu C, 20 V ) c. ( 0.5 mu C, 20 V ) D. ( 1.0 mu, 40 V ) |
12 |
| 870 | Work done in carrying an electric charge ( Q_{1} ) once round a circle of radius ( R ) with a charge ( Q_{2} ) at the centre of the circle: A. ( frac{Q_{1} Q_{2}}{4 pi varepsilon_{Omega} R} ) B. ( infty ) c. ( frac{Q_{1} Q_{2}}{4 pi varepsilon_{0} R^{2}} ) D. |
12 |
| 871 | One Volt is equal to: A . 1 Joule B. 1 Newton/Coulomb c. 1 Joule/Coulomb D. 1 Coulomb/Newton |
12 |
| 872 | The charge ( Q ) and ( -2 Q ) are placed at some distance. What is the locus of point in the plane of the charges where the potential is zero? 1. Parabola 2. Circle 3. Ellipse Write your answer in terms 1,2 and 3 only. |
12 |
| 873 | The equivalent capacitance between points a and b in given arrangement of plates will be:(each plate has the area ‘A’ ( & ) separation between two adjacent plates is ‘d’) A ( cdot frac{2}{3} frac{varepsilon_{o} A}{d} ) B ( cdot frac{3}{2} frac{varepsilon_{o} A}{d} ) c. ( frac{2 varepsilon_{o} A}{d} ) D. ( frac{varepsilon_{o} A}{3 d} ) |
12 |
| 874 | Equipotential surface associated with an electric field which is increasing in magnitude along the y-direction, are A. parallel to ( X Y ) plane B. parallel to ( X Z ) plane C. parallel to ( Y Z ) plane D. coaxial cylinders of increasing radii around the the ( x ) axis |
12 |
| 875 | A small uncharged metallic sphere is positioned exactly at a point midway between two equal and opposite point charges separated by very small distance. If the spheres is slightly displaced towards the positive charge and released, then This question has multiple correct options A. It will oscillate about it’s original position. B. It will move further towards the positive charge. c. Its potential energy will decrease and kinetic energy will increase D. The total energy remains constant but is non-zero |
12 |
| 876 | A capacitor is formed by two square metal-plates of edge ( alpha_{1} ) separated by a distance ( d ). Dielectrics of dielectric constants ( K_{1} ) and ( K_{2} ) are filled in the gap as shown figure. Find the capacitance. |
12 |
| 877 | A capacitor has a capacitance of ( boldsymbol{C} ) when a potential difference of ( V ) is across it. The potential difference is increased to ( 2 V, ) what is the new capacitance? A. ( C ) B. ( 2 C ) ( c .3 C ) D. ( 5 C ) |
12 |
| 878 | A parallel plate condenser with a dielectric of dielectric constant ( boldsymbol{K} ) between the plates has a capacity ( C ) and is charged to a potential ( V ) volt. The dielectric slab is slowly removed from between the plates and then reinserted. The net work done by the system in this process is : A . zero в. ( frac{1}{2}left[(K-1) C V^{2}right. ) c. ( frac{C V^{2}(K-1)}{K} ) D. ( (K-1) C V^{2} ) |
12 |
| 879 | A condenser is charged to a potential difference of ( 120 mathrm{V} ). It’s energy is ( 1 times ) ( 10^{-5} J . ) If battery is there and the space between plates is filled up with a dielectric medium ( left(varepsilon_{r}=5right) . ) Its new energy is ( mathbf{A} cdot 10^{-5} J ) В. ( 2 times 10^{-5} J ) c. ( 3 times 10^{-5} J ) D . ( 5 times 10^{-5} J ) |
12 |
| 880 | The equipotential surfaces corresponding to a single positive charge are concentric spherical shells with the charge at its origin. The spacing between the surfaces for the same change in potential: A. is uniform throughout the field B. is getting closer as ( r rightarrow infty ) c. is getting closer as ( r rightarrow 0 ) D. can be varied as one wishes to |
12 |
| 881 | What are polar and non polar molecules | 12 |
| 882 | In an uniform electric field ( boldsymbol{E}=mathbf{1 0} boldsymbol{N} / boldsymbol{C} ) as shown in figure, find ( boldsymbol{V}_{boldsymbol{A}}-boldsymbol{V}_{boldsymbol{B}} ) ( mathbf{A} cdot 10 V ) B. ( -10 V ) ( mathbf{c} cdot 20 V ) D ( .-20 V ) |
12 |
| 883 | Three point charges ( 3 n C, 6 n C ) and ( 9 n C ) are placed at the corners of an equilateral triangle of side 0.1 m. The potential energy of the system is : A ( .8910 n J ) в. ( 89100 mathrm{mJ} ) c. ( 9910 J ) D. ( 99100 K J ) |
12 |
| 884 | Assertion Each of the plates of a parallel-plate capacitor is given equal positive charge Q. The charges on the facing surfaces will be same. Reason A negative charge ( (-Q) ) will be induced on each of the facing surfaces. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
12 |
| 885 | The capacitive time constant of the RC circuit shown in the figure is: A. zero B. infinity ( c cdot 2 s ) D. 2 ( mu ) s |
12 |
| 886 | Potential difference between two points is equal to A. electric charge / time B. work done/time c. work done/charge D. work done ( times ) charge |
12 |
| 887 | The electric potential at the surface of an atomic nucleus ( (z=50) ) of radius ( 9.0 times 10^{-13} mathrm{cm} ) is: A ( cdot 9 times 10^{5} ) volt B. ( 8 times 10^{6} ) volt c. 80 volt D. 9 volt |
12 |
| 888 | A charge ( +q ) is placed at the origin 0 of ( x-y ) axes as shown in the figure. The work done in taking a charge ( Q ) from ( A ) to B along the straight line ( A B ) is: A ( cdot frac{q Q}{4 pi varepsilon_{0}}left(frac{a-b}{a b}right) ) в. ( frac{q Q}{4 pi varepsilon_{0}}left(frac{b-a}{a b}right) ) c. ( frac{q Q}{4 pi varepsilon_{0}}left(frac{b}{a^{2}}-frac{1}{b}right) ) D. ( frac{q Q}{4 pi varepsilon_{0}}left(frac{a}{b^{2}}-frac{1}{b}right) ) |
12 |
| 889 | For the configuration of media of permitivities ( varepsilon_{o}, varepsilon ) and ( varepsilon_{o} ) between parallel plates each of area ( A ), as show in figure, the equivalent capacitance is ( mathbf{A} cdot varepsilon_{0} A / d ) В ( cdot varepsilon_{0} varepsilon A / d ) C. ( frac{varepsilon_{0} varepsilon A}{dleft(varepsilon+varepsilon_{0}right)} ) D. ( frac{varepsilon_{0} varepsilon A}{left(2 varepsilon+varepsilon_{0}right)} ) |
12 |
| 890 | Four identical charges each of charge are placed at the corners of a square. Then at the centre of the square the resultant electric intensity E and the net electric potential V are A. ( E neq 0, V=0 ) B. ( E=0, V=0 ) c. ( E=0, V neq 0 ) D. ( E neq 0, V neq 0 ) |
12 |
| 891 | What is the angle between electric field and equipotential surfaces? A. 90 always B. O always ( c cdot 0 ) to 90 D. 0 to 180 |
12 |
| 892 | I ne IIgure snows lour palrs ol unılormıy charged spheres. The red spheres are positively charged while the blue spheres are negatively charged. Each sphere has the same amount of charge. Assume each pair is isolated. For which pair there is a point between them on the dotted line where the magnitude of electric field is zero as well as the electric potential is also zero? A. B. 2 ( c cdot 3 ) D. 4 E. None of the pairs has points that meet these conditions |
12 |
| 893 | The charge supplied to a good conductor always resides: A. at the supplied position itself B. on its outer surface C. inside the body D. all of the above |
12 |
| 894 | Which among the following statement is true about the work done in bringing a unit positive charge from point ( P ) to ( Q ) in an electrostatic field? A. Minimum work is done in case of path II B. Maximum work is done in case of path1 c. Work done is same in all the three paths D. Work done is zero in case of path |
12 |
| 895 | The capacity of a parallel plate condenser is inversely proportional to A. Area of each plate B. Dielectric constant c. Permittivity of medium D. Distance between two plates |
12 |
| 896 | A conducting sphere of radius r has a charge. Then: A. The charge is uniformly distributed over its surface, if there is an external electric field. B. Distribution of charge over its surface will be non uniform if no external electric field exist in space. C. Electric field strength inside the sphere will be equal to zero only when no external electric field exists. D. Potential at every point of the sphere must be same. |
12 |
| 897 | Two charges of equal magnitude ‘ ( q ) ‘ are placed in air at a distance ( ^{prime} 2 a^{prime} ) apart and third charge ( -2 q^{prime} ) is placed at midpoint. The potential energy of the system is ( left(epsilon_{0}= ) permittivity of free right. space) : ( ^{mathrm{A}} cdot-frac{q^{2}}{8 pi epsilon_{0} a} ) в. ( -frac{3 q^{2}}{8 pi epsilon_{6} a} ) c. ( -frac{5 q^{2}}{8 pi epsilon_{0} a} ) D. ( -frac{7 q^{2}}{8 pi epsilon_{6} a} ) |
12 |
| 898 | Why is electrostatic potential constant throughout the volume of the conductor and has the same value (as inside) on its surface? |
12 |
| 899 | Identify the dimension of electric potential, A ( cdot L^{2} M T^{-3} I^{-1} ) B . ( L^{1} M T^{-2} I^{-1} ) ( mathbf{c} cdot L^{-2} M T^{-2} I^{-1} ) D. none of the above |
12 |
| 900 | The ratio of charge densities on the surface of two conducting spheres is 3: 2. lithe radii of t: the spheres are ( 4 mathrm{cm} ) and ( 8 mathrm{cm} ) the ratio of the electric potential on the surfaces of the sphere 2 is ( A cdot 3: 4 ) B. 3:1 ( c cdot 1: 3 ) D. 4: 9 |
12 |
| 901 | Four charges ( 1 mathrm{mc}, 2 mathrm{mc}, 3 mathrm{mc}, ldots 6 mathrm{mc} ) are placed on at corner of a square of side ( 1 mathrm{m} . ) The square lies in ( mathrm{XY} ) plane with its centre at origin A. The electric potential at origin at origin B. The electric potential is zero every where along ( x ) axis c. The electric potential is not zero along z-axis D. The electric potential is zero along Z- axis for any orientation of square in ( mathrm{XY} ) plane |
12 |
| 902 | Two concentric shells have radii ( mathbf{R} ) and 2R, charges ( q_{A} ) and ( q_{B} ) and potentials ( 2 V ) and ( (3 / 2) vee ) respectively. Now shell ( B ) is earthed and let charges on them become ( boldsymbol{q}_{boldsymbol{A}}^{prime} ) and ( boldsymbol{q}_{boldsymbol{B}}^{prime} . ) Then: This question has multiple correct options ( mathbf{A} cdot q_{A} / q_{B}=1 / 2 ) ( mathbf{B} cdotleft|q_{A}^{prime}right| /left|q_{B}^{prime}right|=1 ) C. Potential of A after earthing becomes (3/2)V D. Potential difference between A and B after earthing becomes V/2 |
12 |
| 903 | The surface of the sphere A. is an equi-potential surface B. is a zero-potential surface C. is an uncharged surface D. None of these |
12 |
| 904 | The capacity between the adjacent plates of a parallel plate capacitor is ( 10 mu F . ) If we want a capacity of ( 50 mu F ) the number of plates to be used is A. 5 B. 50 ( c cdot 6 ) ( D ) |
12 |
| 905 | When the separation between the two charges is increased the electric potential energy of the charges A. Increases B. Decreases c. Remains unchanged D. May increase or decrease |
12 |
| 906 | Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point? Give reason. |
12 |
| 907 | If the value charge density of a dielectric sphere with a cavity (a shown in the figure) is ( rho . ) Find the electrostatic self energy. |
12 |
| 908 | There are two concentric metal shells of radii ( r_{1} ) and ( r_{2}left(>r_{1}right) . ) If the outer shell has a charge ( q ) and the inner shell is grounded, the charge on the inner shell is A. zero B. ( -left(r_{1} / r_{2}right) ) q c. ( r_{1} r_{2} ) q D. None of thee |
12 |
| 909 | Three capacitors, ( 3 mu F, 6 mu F ) and ( 6 mu F ) are connected in series to a source of 120V. The potential difference, in volts, across the ( 3 mu F ) capacitor will be A . 24 B. 30 ( c cdot 40 ) ( D cdot 60 ) |
12 |
| 910 | A cube of side ‘a’ has a charge ( q ) placed at each of its eight corneres. The potential at the centre of the cube due to all the charges is : A ( cdot frac{16 q}{4 pi varepsilon_{0} a sqrt{3}} ) в. ( frac{16 q}{4 pi varepsilon_{0} a} ) c. ( frac{q}{4 pi varepsilon_{0} a} ) D. ( frac{q}{4 pi varepsilon_{0} a sqrt{3}} ) |
12 |
| 911 | Plot ( A & B ) represent variation of charge with potential difference across the combination (series and parallel) of two capacitors. Then find the value of capacitance of capacitors. A ( .20 mu F, 30 mu F ) B. ( 10 mu F, 40 mu F ) с. ( 10 mu F, 15 mu F ) D. ( 25 mu F, 25 mu F ) |
12 |
| 912 | Five conducting plates are placed parallel to each other Separation between them is ( d ) and area of each plate is ( A ). Plate number 1,2 and 3 are connected with each other and at the same time through a cell of emf ( boldsymbol{E} ). The charge on plate number 1 is ( mathbf{A} cdot E varepsilon_{0} A / d ) B . ( E varepsilon_{0} A / 2 d ) ( mathbf{c} cdot 2 E varepsilon_{0} A / d ) D. zero |
12 |
| 913 | Two equal charges of magnitude ( Q ) each are placed at a distance d apart. Their electrostatic energy is E. A third charge ( -Q / 2 ) is brought midway betway these two charges. The electrostatic energy of the system is now. A . ( -2 E ) B . ( -E ) ( c .0 ) D. E |
12 |
| 914 | Electric potential can be calculated in a A. static electric field B. dynamic electric field c. both static and dynamic electric field D. neither static nor dynamic electric field |
12 |
| 915 | How many ( 6 mathrm{mF}, 200 mathrm{V} ) condensers are needed to make a condenser of ( 18 mathrm{mF} ) ( 600 vee ? ) ( A cdot 9 ) B. 18 ( c cdot 3 ) D. 27 |
12 |
| 916 | Two condensers of capacitance ( 4 mu F ) and ( 5 mu F ) are joined in series. If the potential difference across ( 5 mu F ) is ( 10 V ), then the potential difference across ( 4 mu F ) condenser is : ( mathbf{A} cdot 22.5 V ) B. ( 10 V ) c. ( 12.5 V ) D. ( 25 V ) |
12 |
| 917 | Breakdown voltage is A. voltage at which dielectric behaves as conductor B. voltage at which molecules starts flowing inside the dielectric freely Which of the following is correct regarding above case, A. Both ( B, A ) are correct B. ( B ) is correct c. ( A ) is correct D. None of the above is correct |
12 |
| 918 | The dielectric strength of air is ( 3.0 times ) ( 10^{6} N C^{-1} . ) The largest charge that a ( 0.30 mathrm{cm} ) radius metal sphere can hold without sparking is: A. 9 nc B. 8.2 nc ( c cdot 6 n c ) D. 3 nc |
12 |
| 919 | Five identical conducting plates 1, 2, 3, 4 and 5 are fixed parallel to and equidistant from each other (see figure). Plates ( 2 & 5 ) are connected by a conductor while ( 1 & 3 ) are joined by another conductor. The junction of ( 1 & 3 ) and the plate 4 are connected to a source of constant e.m.f. ( V_{0} . ) Find: (i) The effective capacity of the system between the terminals of the source. (ii) the charges on plates ( 3 & 5 ) Given ( boldsymbol{d}= ) distance between any successive plates ( & boldsymbol{A}= ) area of either face of each plate |
12 |
| 920 | Determine the electric potential at point P due to two point charges each of charge ( +Q, ) with one point charge being at a distance ( mathrm{R} ) and the other being at a distance ( 2 R ) ( A ) [ frac{3 Q}{8 pi_{6} R} ] в. [ frac{2 Q}{12 pi epsilon_{0} R} ] ( c ) [ frac{3 Q}{12 pi epsilon_{0} R} ] D. [ frac{2 Q}{8 pi epsilon_{0} R} ] |
12 |
| 921 | The value of the static dielectric constant of any material is always A. greater than 1 B. equal to 1 c. lesser than 1 D. None |
12 |
| 922 | Three condensers are connected as shown in series. If the insulated plate of ( C_{1} ) is at ( 45 V ) one plate of ( C_{3} ) is earthed find the p.d between the plate of ( C_{2} ) A . ( 10 V ) B . ( 20 V ) ( c .30 V ) D. ( 45 V ) |
12 |
| 923 | Three point charges ( Q_{1}=25 mu C, Q_{2}= ) ( 50 mu C ) and ( Q_{3}=100 mu C, ) are kept at the corners ( A, B ) and ( C ) respectively of an equilateral triangle ABC having each side equal to ( 7.5 mathrm{m} ). Calculate the total electrostatic potential energy of the system |
12 |
| 924 | The plates of a parallel plate capacitor are charged to ( 200 mathrm{V} ) and then, the charging battery is disconnected. Now, a dielectric slab of dielectric constant 5 and thickness ( 4 mathrm{mm} ) is inserted between the capacitor plates. To maintain the original capacity, the increase in the separation between the plates of the capacitor is: A. ( 1.6 mathrm{mm} ) B. ( 3.2 mathrm{mm} ) ( mathrm{c} .0 .8 mathrm{mm} ) D. ( 4.8 mathrm{mm} ) |
12 |
| 925 | (a) Three point charges ( q,-4 q ) and ( 2 q ) are placed at the vertices of an equilateral triangle ( A B C ) of side ( ^{prime} l^{prime} ) as shown in the figure. Obtain the expression for the magnitude of the resultant electric force acting on the charge ( boldsymbol{q} ) (b) Find out the amount of the work done to separate the charges at infinite distance. |
12 |
| 926 | Two concentric spheres of radius ( R ) and ( 2 R ) have charges ( Q ) and ( 2 Q . ) The potential at a point ( mathrm{P} ) situated at a point 3R/2 distance from common centre is ( V, ) Now if outer sphere is earthed, the potential at point ( P ) is : A. ( V / 5 ) в. ( V / 10 ) c. ( V / 3 ) D. ( V ) |
12 |
| 927 | Two small equal point charges of magnitude ( q ) are suspended from a common point o the ceiling by insulating massless strings of equal lengths. They come to equilibrium with each string making angle ( theta ) from the vertical. If the mass of each charge is ( m ) ( mathrm{m}, ) then the electrostatic potential at the center of line joining them will be ( left(frac{1}{4 pi epsilon_{0}}=Kright) ) A ( .2 sqrt{k / m g tan theta} ) B . ( sqrt{k m g tan theta} ) c. ( 4 sqrt{k / m g tan / theta} ) D. ( 4 sqrt{k m g tan theta} ) |
12 |
| 928 | An isolated conductor of any shape has a net charge of ( +15 mu C ). Inside the conductor is a cavity within which is a point-charge of ( +3.0 mu C . ) What is the charge on the cavity wall and on the outer surface of the conductor? | 12 |
| 929 | The electric potential at a point in free space due to a charge ( Q ) coulomb is ( Q times 10^{11} V . ) The electric field at that point is A ( cdot 4 pi varepsilon_{0} Q times 10^{22} V / m ) B . ( 127 pi varepsilon_{0} Q times 10^{20} V / m ) C. ( 4 pi varepsilon_{0} Q times 10^{20} V / m ) D . ( 12 pi varepsilon_{0} Q times 10^{22} mathrm{V} / mathrm{m} ) |
12 |
| 930 | A potential difference of ( 5 V ) is applied across a conductor of length ( 10 mathrm{cm} . ) If drift velocity of electrons is ( 2.5 times ) ( 10^{-4} m / s, ) then electron mobility will be A ( .5 times 10^{-4} mathrm{m}^{2} mathrm{V}^{-1} mathrm{s}^{1} ) B. ( 5 times 10^{-6} mathrm{m}^{2} mathrm{V}^{-1} mathrm{s}^{1} ) c. ( 5 times 10^{-2} mathrm{m}^{2} mathrm{V}^{-1} mathrm{s}^{1} ) D. zero |
12 |
| 931 | If a piece of copper having internal cavity weighs 264 gms.in air and 221 gms. in water, then volume of the cavity is ( ldots . . . . . . . . . . . . . . . . . ) Density of copper ( =8.8 ) ( left.g / c m^{3}right) ) ( mathbf{A} cdot 10 mathrm{cm}^{3} ) В. ( 11 mathrm{cm}^{3} ) ( mathbf{c} cdot 13 c m^{3} ) D. ( 15 mathrm{cm}^{3} ) |
12 |
| 932 | If a charge is placed on a conductor having a pointed end, then A. the charge gets accumulated at the points B. the charge gets distributed around the conductor c. the charge collects inside the conductor D. the charge gets dissipated to the surrounding |
12 |
| 933 | The earth has Volume ‘V’ and surface area ‘A’ then its capacitance would be |
12 |
| 934 | Two condensers each of capacitance ( 2 mu F ) are connected in parallel and this combination is connected in series with a ( 12 mu F ) capacitor. The resultant capacity of the system will be: A. ( 16 mu f ) в. ( 13 mu f ) c. ( 6 mu f ) D. ( 3 mu f ) |
12 |
| 935 | Two point charges ( 4 mu C ) and ( -6 mu C ) are seperated by a distance of ( 10 mathrm{cm} ) in air. At what point between the charges on the line joining the charges is the potential zero. |
12 |
| 936 | The equivalent capacitance of three capacitors of capacitance ( C_{1}, C_{2} ) and ( C_{3} ) connected in parallel is 12 units and the product ( C_{1} C_{2} C_{3}=48 . ) When the capacitors ( C_{1} ) and ( C_{2} ) are connected in parallel the equivalent capacitance is 6 units. Then the capacitance are: ( mathbf{A} cdot 1.5,2.5,8 ) B. 2,3,7 ( mathbf{c} cdot 4,2,6 ) D. 1,5,6 |
12 |
| 937 | A point charge of magnitude ( +1 mu c ) is fixed at ( (0,0,0) . ) An isolated uncharged spherical conductor is fixed its centre at ( (4 m, 0,0) . ) The potential and the induced electric field at the centre of the sphere is A . ( 1.8 times 10^{5} V ) and ( -5.625 times 10^{6} V / m ) B. ( 0 mathrm{V} ) and ( 0 mathrm{V} / mathrm{m} ) C . ( 2.25 times 10^{5} V ) and ( -5.625 times 10^{6} V / m ) D. ( 2.25 times 10^{5} V ) and ( 0 V / m ) |
12 |
| 938 | A current of ( 10 A ) is maintained in a conductor of cross-section ( 1 mathrm{cm}^{2} ). If the number density of free electrons be ( 9 times 10^{28} m^{-3}, ) the drift velocity of free electrons is A. ( 6.94 times 10^{-6} mathrm{m} / mathrm{s} ) B. ( 5.94 times 10^{-2} mathrm{m} / mathrm{s} ) c. ( 1.94 times 10^{-3} mathrm{m} / mathrm{s} ) D. ( 2.94 times 10^{-4} mathrm{m} / mathrm{s} ) |
12 |
| 939 | The potential difference between points ( A ) and ( D ) in the given circuit is:- ( A cdot frac{2}{V} ) ( B cdot frac{8}{0} V ) ( c cdot frac{4}{3} v ) D. ( 2 V ) |
12 |
| 940 | If a unit charge is taken from one point to another over an equipotential surface, then : A. Work is done on the charge B. Work is done by the charge c. work done on the charge is constant D. No work is done |
12 |
| 941 | Explain series combination of Capacitors. Derive the formula for equivalent capacitance. | 12 |
| 942 | The effective capacitance between ( boldsymbol{A} ) and ( B ) will be A. ( 0.5 F ) В. ( 1.5 F ) ( c .2 F ) D. 2.5 |
12 |
| 943 | Capacitance of a capacitor made by a thin metal foil is ( 2 mu F ). If the foil is folded with paper of thickness ( 0.15 mathrm{mm} ) dielectric constant of paper is 2.5 and width of paper is ( 400 mathrm{mm} ), the length of foil will be A. ( 0.34 mathrm{m} ) B. 1.33 ( m ) c. ( 13.4 mathrm{m} ) D. 33.9 m |
12 |
| 944 | Equipotential surfaces are shown in fig, then the electric field strength will be A . ( 100 mathrm{Vm}-1 ) along ( mathrm{X} ) -axis B. ( 100 mathrm{Vm}-1 ) along ( mathrm{Y} ) -axis c. ( 200 mathrm{Vm}-1 ) at an angle ( 120^{circ} ) wirh ( mathrm{x} ) -axis D. 50 Vm-1 at an angle ( 180^{circ} ) wirh ( x ) -axis |
12 |
| 945 | Water is not used as a dielectric between the plates of a capacitor because its. A. Dielectric constant is very low B. Dielectric strength is very low c. Dielectric constant is very highh D. Dielectric strength is very large |
12 |
| 946 | A ( 10.0 mu F ) parallel-plate capacitor with circular plates is connected to a ( 12.0 V ) battery. How much charge ( (text { in } mu C) ) would be on the plates if the capacitor were connected to the ( 12.0 V ) battery after the radius of each plate was doubled without changing their separation? |
12 |
| 947 | The diagram shows equipotential lines from an unknown charge configuration. Determine the direction of the field at ( A ) ( A cdot U p ) B. Down c. Left D. Right |
12 |
| 948 | The surface of a planet is found to be uniformly charged. When a particle of mass ( m ) and no charge is thrown at an angle from the surface of the planet, it has a parabolic trajectory as in projectile motion with horizontal range ( L ). A particle of mass ( m ) and charge ( q ) with the same initial conditions has a range ( frac{L}{2} ). The range of particle of mass ( m ) and charge ( 2 q ) with the same initial conditions is : A. ( L ) в. ( frac{L}{2} ) c. ( frac{L}{3} ) D. ( frac{L}{4} ) |
12 |
| 949 | Inside a uniformly charged spherical conductor, the electric: This question has multiple correct options A. Potential is zero everywhere B. Potential is non-zero and same everywhere C. Field is zero everywhere D. Field has the same magnitude everywhere but it is not zero |
12 |
| 950 | 27 identical drops of mercury are charged simultaneously with the same potential of ( 10 V . ) Assuming the drop to the spherical, if all the charged drops are made to combine to form one large drop, then its potential will be ( boldsymbol{V} ) A . 40 B. 90 ( c .160 ) D. 10 |
12 |
| 951 | A charge ( Q ) is placed inside the sphere of radius ( a ) then what will be the value of charge that will be accumulated on the surface of the sphere, ( mathbf{A} cdot mathbf{0} ) в. ( Q ) c. ( -Q ) D. – 2Q |
12 |
| 952 | If the inductance and capacitance are both doubled in L-C-R circuit, the resonant frequency of the circuit will: A. Decrease to one-half of the original value B. Decrease to one-fourth of the original value c. Increase to twice the original value D. Decrease to twice the original value |
12 |
| 953 | Parallel plate condenser having a plate separation d is charged to a potential ( V ) It is then isolated. The intensity of the separation of the plates is then doubled The new electric field intensity is : A . 2 E B. E ( c cdot E / 4 ) D. E/2 |
12 |
| 954 | Name the unit of electrical potential: A. Coulomb B. Watt c. Joule D. volt |
12 |
| 955 | A charge of ( 10^{-9} C ) moves from ( X ) to ( Z ) Find the work done by the electric field due to the charge ( Q=2 C ) in moving the charge from ( X ) to ( Z ). The value of coulomb’s constant is ( 9 times 10^{9} N m^{2} C^{-2} ) A . ( 0 . J ) В. ( 150 J ) ( c .300 J ) D. ( 560 J ) E. ( 1,000 J ) |
12 |
| 956 | Assertion There is no current in the metals in the absence of electric field. Reason Motion of free electrons are random. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
12 |
| 957 | An infinite number of charges each equal to ( ^{prime} q^{prime} ) are placed along the ( X ) -axis at ( x=1 ) ( x=2, x=4, x=8 ) The potential at the point ( x=0 ) due to this set of charges is : ( ^{A} cdot frac{Q}{4 pi epsilon_{0}} ) в. ( frac{2 Q}{4 pi epsilon_{0}} ) с. ( frac{3 Q}{4 pi epsilon_{0}} ) D. ( frac{Q}{pi epsilon_{0}} ) |
12 |
| 958 | f a unit charge is taken from one point to another over an equipotential surface, then work done on the charge is A. Positive B. Negative c. zero D. constant |
12 |
| 959 | If ( 4 times 10^{20} e V ) of energy is required to move a charge of 0.25 coulomb between two points, the p.d between them is: A . 256 ( v ) B. 512 ( v ) ( c cdot 123 v ) D. 215 V |
12 |
| 960 | A pendulum ( positively charged and hinged at some length above the plate) is swinging above a parallel plate (infinitely large and having negative charge),now consider the following statements, (consider gravity) A. angular momentum about the hinge point of the ball will be max at lowest point B. electric potential energy will be max at highest point c. gravitational potential energy will be lowest at highest point D. none of the above |
12 |
| 961 | There is 10 units of charge at the centre of a circle of radius 10m. The work done in moving 1 unit of charge around the circle once is: A . zero B. 10 units c. 100 units D. 1 unit |
12 |
| 962 | A charge of ( 20 mu C ) is placed on the positive plate of an isolated parallelplate capacitor of capacitance ( 10 mu F ) Calculate the potential difference developed between the plates. |
12 |
| 963 | Find the equivalent capacitance across A and B for the arrangement shown in figure. All the capacitors are of capacitance ( mathbf{C}: ) A ( cdot frac{3 C}{14} ) в. ( frac{C}{8} ) c. ( frac{3 C}{16} ) D. none of these |
12 |
| 964 | Two charges of ( +10 mu mathrm{C} ) and ( +20 mu mathrm{C} ) are separated by a distance of 2 cm. The net potential (electric) due to the pair at the middle point of the line joining the two charges, is : A . 27 MV B. 18 MV c. 20 MV D. 23 MV |
12 |
| 965 | The equivalent capacitance between points ( mathrm{M} ) and ( mathrm{N} ) is : A . Infinity в. ( c_{1}+frac{C_{2}}{C_{1}} ) ( c_{C_{2}+frac{C_{2}}{C_{1}}} ) D. ( frac{C_{1} C_{2}}{C_{1}+C_{2}} ) |
12 |
| 966 | The potential and electric field in the above set up if the consecutive charges have opposite sign is : A ( cdot frac{q}{6 pi epsilon_{0}} ) and ( frac{q}{5 pi epsilon_{0}} ) B. ( frac{q}{6 pi epsilon_{0}} ) and ( frac{q}{6 pi epsilon_{0}} ) c. ( frac{q}{5 pi epsilon_{0}} ) and ( frac{q}{6 pi epsilon_{0}} ) D. ( frac{q}{4 pi epsilon_{0}} ) and ( frac{q}{6 pi epsilon_{0}} ) |
12 |
| 967 | Why should electrostatic field be zero inside a conductor? |
12 |
| 968 | Find the correct relation from the following: A. Work done=charge ( times ) power B. Work done=charge ( times ) potential difference C. Work done=current ( times ) voltage D. All |
12 |
| 969 | in a certain region of free space a non- uniform electric field which depends on X-coordinates is given by ( overrightarrow{boldsymbol{E}}=boldsymbol{E}_{0} boldsymbol{x} hat{boldsymbol{i}} ) What is the total amount of electric potential energy contained within the cube of sides of length L as shown below? A ( cdot frac{1}{5} varepsilon_{0} E_{0}^{2} L^{5} ) B ( cdot frac{1}{5} varepsilon_{0} E_{0}^{2} L^{6} ) C ( cdot frac{1}{6} varepsilon_{0} E_{0}^{2} L^{6} ) D ( cdot frac{1}{2} varepsilon_{0} E_{0}^{2} L^{5} ) |
12 |
| 970 | Three charges ( -q, Q ) and ( -q ) are placed at equal distances on a straight line. If the total potential energy of the system of three charges is zero, then the ratio ( mathrm{Q} ) ( : q ) is A .1: 2 B . 2: 1 c. 1: 1 D. 1: 4 |
12 |
| 971 | An infinite number of equal charges ( (q ) each) are placed at distance ( x= ) ( 1,2,4,8, dots dots ). ( 0 . ) Then the electric potential at the origin ( (x=0) ) will be : A. zero B. infinite c. ( frac{q}{4 pi varepsilon_{0}} ) D. ( frac{2 q}{4 pi varepsilon_{0}} ) |
12 |
| 972 | Seven capacitors, each of capacitance ( 2 mu F ) are to be connected to obtain a capacitance of ( 10 / 11 mu F ).Which of the following combinations is possible? A. 5 in parallel 2 in series B. 4 in parallel 3 in series c. 3 in parallel 4 in series D. 2 in parallel 5 in series |
12 |
| 973 | A parallel-plate air capacitor of capacitance ( 245 p F ) has a charge of magnitude ( 0.148 mu C ) on each plate. The plates are ( 0.328 m m ) apart. What is the potential difference between the plates ( (text { in } V) ? ) |
12 |
| 974 | The amount of energy that a unitary point electric charge would have, if located at any point in space, is defined its: A. electric potential energy B. electric potential c. electric potential difference D. electric field |
12 |
| 975 | Which of the following can be used as dielectric? A. Plastics в. Mica c. Porcelain D. All of the above |
12 |
| 976 | Electric field as a function of distance from the centre of a uniformly charged solid sphere is mathematically: A . a discontinuos function B. inversely related to distance from the centre c. proportional to distance from the centre D. none of the above |
12 |
| 977 | A condenser of capacity ( 0.2 mu F ) is charged to a potential of 600 V. The battery is now disconnected and the condenser of capacity ( 1 mu F ) is connected across it. The potential of the condenser will reduce to ( mathbf{A} cdot 600 V ) B. ( 300 V ) c. ( 100 V ) D. ( 120 V ) |
12 |
| 978 | The Sl units of potential is | 12 |
| 979 | Four metallic plates each with a surface area of one side ( A ) are placed at a distance ( d ) from each other as shown in figure. Then the capacitance of the system between ( X ) and ( Y ) is A. B. ( frac{2 epsilon_{0} A}{3 d} ) c. ( frac{3 epsilon_{0} A}{d} ) D. |
12 |
| 980 | The capacitance of a parallel-plate capacitor is ( C_{0} ) when the region between the plates has air. This region is now filled with a dielectric slab of dielectric constant K. The capacitor is connected to a cell emf ( varepsilon_{1} ) and the slab is taken out. This question has multiple correct options A. Charge ( varepsilon C_{0}(K-1) ) flows through the cell B. Energy ( varepsilon^{2} C_{0}(K-1) ) is absorbed by the cell. C. The energy stored in the capacitor is reduced by ( varepsilon^{2} C_{0}(K-1) ) D. The external agent has to do ( frac{1}{2} varepsilon^{2} C_{0}(K-1) ) amount of work to take the slab out. |
12 |
| 981 | A hollow metal sphere of radius ( 10 mathrm{cm} ) is charged such that the potential on its surface becomes ( 80 mathrm{V} ). The potential at the centre of the sphere is? A . ( 80 v ) в. 800 V c. ( 8 v ) D. zero |
12 |
| 982 | The force of attraction between the plates of a charged condenser is : A ( cdot q^{2}left(2 varepsilon_{0} Aright) ) B ( cdot q^{2}left(2 varepsilon_{0} A^{2}right) ) ( mathbf{c} cdot q^{2} /left(2 varepsilon_{0} Aright) ) D. none of these |
12 |
| 983 | Two spheres of radii ( 3 mathrm{cm} ) and ( 5 mathrm{cm} ) are charged to potentials 3000 V and 4500 V respectively. They are then connected by a thin metallic wires. The loss of electric energy in this process is? ( mathbf{A} cdot 2 times 10^{-8} mathbf{J} ) B ( cdot 4 times 10^{-8} mathrm{J} ) D . ( 2.36 times 10^{-7} ) J |
12 |
| 984 | A capacitor of capacitance ( boldsymbol{C}=mathbf{1 5 p} boldsymbol{F} ) is charged with voltage ( V=500 V . ) The electric field inside the capacitor with dielectric is ( 10^{6} V / m ) and the area of the plate is ( 10^{-4} m^{2}, ) then the dielectric constant of the medium is : ( left(varepsilon_{0}=right. ) ( 8.85 times 10^{-12} ) in S.l.units A. 12.47 B. 8.47 c. 10.85 D. 14.85 |
12 |
| 985 | A charge of 10 e.s.u is placed at the distance of ( 2 mathrm{cm} ) from a charge of 40 e.s.u and ( 4 mathrm{cm} ) from another charge of 20 e.s.u.The potential energy of charged 10 e.s.u is? A. 87.5 B. 112.5 c. 150 D. 250 |
12 |
| 986 | Two large, parallel conducting plates ( x ) and ( Y, ) kept close to each other, are given charges ( Q_{1} ) and ( Q_{2}left(Q_{1}>Q_{2}right) ). The four surfaces of the plates are ( A, B, C ) and ( D, ) as shown in figure. Then : This question has multiple correct options A ‘ the charge on A is ( frac{1}{2}left(Q_{1}+Q_{2}right) ) B ‘ the charge on B is ( frac{1}{2}left(Q_{1}-Q_{2}right) ) c. The charge on ( c ) is ( -frac{1}{2}left(Q_{1}-Q_{2}right) ) D ‘ the charge on D is ( frac{1}{2}left(Q_{1}+Q_{2}right) ) |
12 |
| 987 | A dielectric slab fills the lower half of a parallel plate capacitor as shown in figure : (Take plate are as ( boldsymbol{A} ) ) This question has multiple correct options A . equivalent capacity of the system is ( left(left(varepsilon_{0} A / 2 dright)(1+right. ) ( K) ) B. the net charge of the lower half of the left hand plate is ( 1 / K ) times the charge on the upper half of the plate C. net charges on the lower and upper halves of the left hand plate are different D. net charge on the lower hand of the left hand plate is ( frac{K varepsilon_{0} A}{2 d} times V ) |
12 |
| 988 | The equivalent capacitance between point ( a ) and ( b ) in the combination of capacity figure is ( A cdot 15 mu F ) B. ( 10 mu F ) с. ( 11.2 mu F ) D. ( 7.4 mu F ) |
12 |
| 989 | A parallel plate capacitor having capacitance ( C ) has two plates of same area ( A ) and thickness t. The figure shows the charges available on the four surfaces of the plates. The potential difference V between the two plates is given by: A ( cdot frac{q_{2}-q_{3}}{2 C} ) в. ( frac{q_{2}-q_{3}}{C} ) c. ( frac{q_{1}-q_{4}}{2 C} ) D. ( frac{q_{1}-q_{4}}{C} ) |
12 |
| 990 | Angle between an equipotential surface and electric lines of force is : A . ( 0^{circ} ) B. ( 90^{circ} ) ( c cdot 180^{circ} ) D. ( 270^{circ} ) |
12 |
| 991 | An uncharged parallel plate capacitor filled with a dielectric of dielectric constant ( K ) is connected to an air filled identical parallel capacitor charged to potential ( V_{1} . ) If the common potential is ( V_{2}, ) the value of ( K ) is A. ( frac{V_{1}-V_{2}}{V_{1}} ) B. ( frac{V_{1}}{V_{1}-V_{2}} ) c. ( frac{V_{2}}{V_{1}-V_{2}} ) D. ( frac{V_{1}-V_{2}}{V_{2}} ) E ( cdot frac{V_{1}-V_{2}}{V_{1}+V_{2}} ) |
12 |
| 992 | Two small identical metal balls ( A ) and ( B ) of radius ‘ ( r^{prime} ) are placed apart. The distance between centre of balls is ‘a ( _{0} ). The net potential of ball ( A ) is ( V_{1} ) and that of ( B ) is ( V_{2} . ) Let ( q_{1} ) and ( q_{2} ) are the charges on balls ( A ) and ( B ) respectively. Then the charges on ( A ) and ( B ) are ( left(operatorname{given} r<<a_{0}right) ) A ( cdot q_{1}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}-V_{2} rright)}{a_{0}^{2}-r^{2}} ) B. ( quad q_{1}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}+V_{2} rright)}{a_{0}^{2}+r^{2}} ) ( ^{mathbf{C}} cdot_{q_{2}}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}+V_{2} rright)}{a_{0}^{2}+r^{2}} ) D. ( _{q_{2}}=4 pi varepsilon_{0} frac{a_{0} rleft(V_{1} a_{0}-V_{2} rright)}{a_{0}^{2}-r^{2}} ) |
12 |
| 993 | Two charges ( +Q ) and ( -2 Q ) are placed at ( (- ) a,0) ( &(+a, 0) ). The locus of points in the plane of the charges where the potential is zero will be : A. straight line B. circle c. parabola D. ellipse |
12 |
| 994 | The waves which are produced by accelerated electrons in electronic circuits are A . ‘-‘-waves B. ‘+’waves c. Radio waves D. Infrared rays |
12 |
| 995 | A parallel plate capacitor has area ( 20 c m^{2} ) and separation between the plates is 0.1 m ( m . ) The dielectric break down strength is ( 3 times 10^{6} v / m ) The maximum r.m.s voltage which can be safely applied is : |
12 |
| 996 | Calculate the electric potential at the center of the square: ( A ) в. ( k frac{29}{x^{2}} ) ( c cdot_{k} frac{4 q}{c^{2}} ) D. ( k frac{49}{6} ) ( E ) [ k frac{(4 sqrt{2})}{s} ] |
12 |
| 997 | Assertion A capacitor blocks direct current in the steady state. Reason The capacitive reactance of the capacitor is inversely proportional to frequency f of the source of e.m.f… A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 998 | All the capacitance in the figure are of capacitance ( C . ) The effective capacitance between ( P ) and ( Q ) is : 4.20 3. ( 3 C ) ( c cdot 4 C ) D. ( 1.5 C ) |
12 |
| 999 | Four equipotential curves in an electric field are shown in the figure. A,B,C are three points in the field. If electric intensity at ( A, B, C ) are ( E_{A}, E_{B}, ) and ( E_{C} ) then: ( mathbf{A} cdot E_{A}=E_{B}=E_{C} ) в. ( E_{A}>E_{B}>E_{C} ) c. ( E_{A}<E_{B}E_{B}<E_{C} ) |
12 |
| 1000 | A proton is moved ( 15 mathrm{cm} ) on path parallel to the field lines of a uniform electric field of ( 2.0 times 10^{5} mathrm{V} / mathrm{m} ) What are the possible change in potential ?consider both cases of a moving the proton. |
12 |
| 1001 | At what point on the line joining the two charge is the electric potential zero. | 12 |
| 1002 | From a supply of identical capacitors rated ( 8 m F, 250 V ), the minimum number of capacitors required to form a composite ( 16 m F, 1000 V ) is : A . 2 B. 4 c. 16 D. 32 |
12 |
| 1003 | Consider a capacitor-charging circuit. Let ( Q_{1} ) be the charge given to the capacitor in a time interval of ( 10 m s ) and ( Q_{2} ) be the charge given in the next time interval of 10 ms. Let ( 10 mu C ) charge be deposited in a time interval ( t_{1} ) and the next ( 10 mu C ) charge is deposited in the next time interval ( t_{2} ) A. ( Q_{1}>Q_{2}, t_{1}>t_{2} ) в. ( Q_{1}>Q_{2}, t_{1}<t_{2} ) c. ( Q_{1} t_{2} ) |
12 |
| 1004 | A particle of mass ( 1 g m ) and charge ( 1 mu C ) is held at rest on a frictional horizontal surface at distance ( 1 mathrm{m} ) from a fixed charge ( 2 m C . ) If the particle is released, it will be repelled. The speed of the particle when it is at a distance of ( 10 m ) from the fixed charge will be: A ( cdot 60 m s^{-1} ) B. ( 100 mathrm{ms}^{-1} ) ( mathrm{c} .90 mathrm{ms}^{-1} ) D. ( 180 m s^{-1} ) |
12 |
| 1005 | Two equal positive charges are kept at points ( A ) and ( B . ) The electric potential at the points between ( A ) and ( B ) (excluding these points) is studied while moving from ( A ) to ( B ). The potential A. continuously increases B. continuously decreases c. increases then decreases D. decreases then increases |
12 |
| 1006 | In the circuit shown in the figure, there are two parallel plate capacitors each of the capacitance ( C ) The switch ( S_{1} ) is pressed first to fully charge the capacitor ( C_{1} ) and then released. The switch ( S_{2} ) is then pressed to charge the capacitor ( C_{1} ) 2. After some time, ( S_{2} ) is released and then ( S_{3} ) is pressed. After some time, A. the charge on the upper plate of ( C_{1} ) is ( 2 C V_{o} ) B. The charges on the upper plate of ( C_{1} ) is ( C V_{o} ) c. The charge on the upper plate of ( C_{2} ) is 0 D. The charge on the upper plate of ( C_{2} ) is ( -C V_{o} ) |
12 |
| 1007 | A cube of side ( x ) has a charge ( q ) at each of its vertices. The potential due to this charge array at the centre of the cube is A ( cdot frac{4 q}{3 pi varepsilon_{0} x} ) В. ( frac{4 q}{sqrt{3} pi varepsilon_{0} x} ) c. ( frac{3 q}{4 pi varepsilon_{0} x} ) D. ( frac{2 q}{sqrt{3} pi varepsilon_{0} x} ) |
12 |
| 1008 | Assertion A capacitor can be given only a limited quantity of charge Reason A capacitor is an arrangement which can store sufficient quantity of charge A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
12 |
| 1009 | When two capacitors of capacities ( 3 mu F ) and ( 6 mu F ) are connected in series and connected to ( 120 V, ) the potential difference across ( 3 mu F ) is: A . ( 40 V ) B. ( 60 V ) c. ( 80 V ) D. ( 180 V ) |
12 |
| 1010 | Five identical plates are connected across a battery as in figure. If the charge on plate 1 be ( +q ), then the charges on the plates 2,3,4 and 5 are: ( mathbf{A} .-q,+q,-q,+q ) в. ( -2 q,+2 q,-2 q,+q ) c. ( -q,+2 q,-2 q,+q ) D. none of the above. |
12 |
| 1011 | Find the change in the potential energy of the proton in the displacement. A. ( -6.4 times 10^{-15} J ) В. ( 6.4 times 10^{-15} mathrm{J} ) c. ( -6.4 times 10^{-19} J ) D. ( 6.4 times 10^{-19} mathrm{J} ) |
12 |
| 1012 | A thunder cloud and the earth’s surface may be regarded as a pair of charged parallel plates separated by a distance ( h ) and the capacitance of the system is C. When a flash of mean current ‘ ( i ) ‘ occurs for a time duration ‘t’, the electric field strength between the cloud and earth is: ( mathbf{A} cdot frac{i t}{C} ) B. Cit c. ( frac{i t}{C h} ) D. ( frac{text { Cit }}{h} ) |
12 |
| 1013 | Two parallel-plate vacuum capacitors have areas ( A_{1} ) and ( A_{2} ) and equal plate spacing d. Show that when the capacitors are connected in parallel, the equivalent capacitance is the same as for a single capacitor with plate area ( A_{1}+A_{2} ) and spacing d. |
12 |
| 1014 | A parallel plate capacitor with air as dielectric is charged to a potential ‘V using a battery. Removing the battery, the charged capacitor is then connected across an identical uncharged parallel plate capacitor filled with wax of dielectric constant ‘K’ the common potential of both the capacitor is A. V volts B. kV volts ( c cdot(k+1) v v o l t s ) D. ( frac{V}{k+1} ) volts |
12 |
| 1015 | A parallel plates capacitor is located horizontally such that one of the plates is submerged in a liquid while the other is above the liquid surface. When plates are charged the level of liquid A . rises B. falls c. remains unchanged D. may rise or fall depending on the amount of charge |
12 |
| 1016 | What is the electronic potential at the centre of square of side 1 m? The charges ( 1 times 10^{-8} C,-2 times 10^{-8} C, 3 times ) ( 10^{-8} ) Cand ( 2 times 10^{-8} C ) are placed at the corners of the square. |
12 |
| 1017 | How accurate is one-dimensional model? A. Less accurate B. Quite accurate c. cannot say D. None |
12 |
| 1018 | A capacitor of capacitance ( C_{0} ) is charged to a potential ( V_{0} ) and then isolated. A small capacitor ( C ) is then charged from ( C_{0}, ) discharged and charged again. This process is being repeated ( n ) times. Due to this, the potential of the larger capacitor is decreased to ( V ). The value of ( C ) is : ( ^{mathbf{A}} cdot_{C_{0}}left(frac{V_{0}}{V}right)^{1 / n} ) ( ^{mathrm{B}} C_{0}left[left(frac{V_{0}}{V}right)^{1 / n}-1right] ) ( ^{mathbf{c}} cdot_{C_{0}}left[left(frac{V}{V_{0}}right)-1right]^{n} ) ( ^{mathrm{D}} C_{0}left[left(frac{V_{0}}{V}right)^{n}+1right] ) |
12 |
| 1019 | Five identical capacitor plates, each of area ( A, ) are arranged such that the adjacent plates are at a distance ( boldsymbol{d} ) a part. The plates are connected to a source of emf ( V ) as shown in figure. Match the following? |
12 |
| 1020 | Two neutral conducting spheres are next to each other and touching each other, They are also each separated from the table with an insulating stand. Then, a negatively charged rod is brought near, but not touching, sphere A. The two spheres are then separated by touching only their insulating base Finally, the charged rod is removed. What are the charges of sphere ( A ) and sphere B? A. Sphere A is positive while sphere B is negative B. Sphere A is negative while sphere B is positive c. Both spheres are positively charged. D. Both spheres are negatively charged |
12 |
| 1021 | Two charges are placed at a distance apart. If a glass slab is placed between them, force between them will A. be zero B. increase. c. decrease. D. remains the same |
12 |
| 1022 | If 100 joule of work must be done to move electric charge equal to ( 4 C ) from a place, where potential is -10 volt to another place, where potential is ( V ) volt, find the value of ( V ) |
12 |
| 1023 | topp Q трерош (и) onstant EMF is connected to the system such that B is connected to the positive terminal and A and c are nected to the negative terminal Vhich of the following diagrams orrectly depicts the isolines of electric otential (shown as dotted lines) in the egion between the plates? |
12 |
| 1024 | A parallel plate capacitor has capacitance ( C . ) If it is equally filled the parallel of materials of dielectric constant ( K_{1} ) and ( K_{2} ) its capacity becomes ( C_{1} . ) The ratio of ( C_{1} ) and ( C ) is A. ( K_{1}+K_{2} ) в. ( frac{K_{1} K_{2}}{K_{1}+K_{2}} ) c. ( frac{K_{1}+K_{2}}{K_{1} K_{2}} ) D. ( frac{2 K_{1} K_{2}}{K_{1}+K_{2}} ) |
12 |
| 1025 | A uniform electric field of magnitude ( 290 V / m ) is directed in the positive ( x ) direction. ( A+13.0 mu C ) charge moves from the origin to the point ( (x, y)= ) ( (20.0 c m, 50.0 c m) ) What is the change in the potential energy of the charge field system? A . ( -754 J ) в. ( -754 m J ) c. ( -754 k J ) D. ( -754 mu J ) |
12 |
| 1026 | An electron is taken from point ( A ) to point ( B ) along the path ( A B ) in a uniform electric field of intensity ( boldsymbol{E}=mathbf{1 0} boldsymbol{V m}^{-1} ) Side ( A B=5 m, ) and side ( B C=3 m ) Then, the amount of work done on the electron by us is : A. 50 ev B. 40 ev c. – -50 ev D. -40 eV |
12 |
| 1027 | Effective capacitance of parallel combination of two capacitors ( C_{1} ) and ( C_{2} ) is ( 10 mu F ). when these capacitors are individually connected to a voltage source of ( 1 V ), the energy stored in the capacitor ( C_{2} ) is 4 times that of ( C_{1} ). If these capacitors are connected in series, their effective capacitance will be: ( mathbf{A} cdot 8.4 mu F ) в. ( 3.2 mu F ) c ( .1 .6 mu F ) D. ( 4.2 mu F ) |
12 |
| 1028 | How many electrons should be removed from a conductor so that it acquires a positive charge of 3.5 nC? |
12 |
| 1029 | A charge ‘ ( Q ) ‘ is placed at each corner of a cube of side ‘a’. The potential at the centre of the cube is : A ( cdot frac{8 Q}{pi varepsilon_{0} a} ) в. ( frac{4 Q}{4 pi varepsilon_{0} a} ) c. ( frac{4 Q}{sqrt{3} pi varepsilon_{0} a} ) D. ( frac{2 Q}{pi varepsilon_{0} a} ) |
12 |
| 1030 | Two conducting spheres of radii ( r_{1} ) and ( r_{2} ) are charged to the same surface charge density. The ratio of electric fields near their surface is : A ( cdot r_{1}^{2} / r_{2}^{2} ) B . ( r_{2}^{2} / r_{1}^{2} ) ( mathbf{c} cdot r_{1} / r_{2} ) D. 1: 1 |
12 |
| 1031 | Two point charges ( +q ) and ( -q ) are located at points ( (0,0,-a) ) and ( (0,0, a) ) respectively. The potential at a point ( (0,0, z) ) where ( z>a ) is A ( cdot frac{2 q a}{4 pi epsilon_{0}left(z^{2}+a^{2}right)} ) в. ( frac{q}{4 pi epsilon_{0} a} ) c. ( frac{q a}{4 pi epsilon_{0} z^{2}} ) D. ( frac{2 q a}{4 pi epsilon_{0}left(z^{2}-a^{2}right)} ) |
12 |
| 1032 | An equipotential surface is a surface with constant value of potential at all points on the surface. What is the amount of work done in moving a ( 2 mu c ) charge between two points at ( 3 c m ) apart on an equipotential surface? |
12 |
| 1033 | A capacitor of capacitance ( 10 mu F ) is charged a potential ( 50 V ) with a battery. The battery is now disconnected and an additional charge ( 200 mu C ) is given to the positive plate of the capacitor. The potential difference across the capacitor will be : A . ( 50 V ) B. ( 80 V ) ( mathbf{c} cdot 100 V ) D. ( 60 V ) |
12 |
| 1034 | Consider a finite insulated, uncharged conductor placed near a finite positively charged conductor. The uncharged body must have a potential: A. less than the charged conductor and more than at infinity. B. more than the charged conductor and less than at infinity. c. more than the charged conductor and more than at infinity. D. less than the charged conductor and less than at infinity. |
12 |
| 1035 | If the susceptibility of dia, para and ferro magnetic materials are Xd. ( X p . X f ) respectively, then A. ( X d<X p<X f ) в. ( X f<X p<X d ) c. ( X f<X d<X p ) D. ( X d<X f<X p ) |
12 |
| 1036 | The surface of a conductor is an equipotential surface: |
12 |
| 1037 | Two point charges ( +boldsymbol{q} ) and ( -boldsymbol{q} ) are held fixed at ( (-d, 0) ) and ( (d, 0) ) respectively of a ( (x, y) ) coordinate system, then A. the electric field ( vec{E} ) at all points on the ( x ) -axis has the same direction B. ( vec{E} ) at all points on the ( y ) -axis is along ( hat{i} ) C. positive work is done in bringing a test charge from infinity to the origin D. all of the above |
12 |
| 1038 | What is the work required to set up the four-charge configuration of the figure, assuming the charges are initially infinitely far apart? A ( cdot frac{q^{2}}{4 pi epsilon_{0} a}(4+sqrt{2}) ) В ( cdot frac{q^{2}}{4 pi epsilon_{0} a}(4-sqrt{2}) ) c. ( frac{q^{2}}{4 pi epsilon_{0} a}(-4+sqrt{2}) ) D. ( frac{q^{2}}{4 pi epsilon_{0} a}(-4-sqrt{2}) ) |
12 |
| 1039 | Derive the formula for equivalent capacitance when the capacitors are connected in series. | 12 |
| 1040 | 5 00 10 |
12 |
| 1041 | The potential difference between points ( A ) and ( B, ) in a section of a circuit shown, is A. 5 volt B. 1 Volt c. 10 volt D. -16volt |
12 |
| 1042 | Suppose ( n ) conducting plates are placed face to face, and the distance between two successive plates is ( d ) Each plate is half of the area of the previous one. If area of first plate is ( A ). If the area of the first plate is ( A ), the equivalent capacitance of the system is ( operatorname{given} operatorname{as} frac{varepsilon_{0} A}{dleft(x^{n}-2right)} . ) Find ( x ) |
12 |
| 1043 | Find the dimensions of capacitance : ( mathbf{A} cdot=left[M^{-1} L^{2} T^{4} A^{-2}right] ) B . ( =left[M^{-1} L^{-2} T^{-4} A^{2}right] ) ( mathbf{c} cdot=left[M^{-1} L^{-1} T^{4} A^{2}right] ) D. ( =left[M^{-1} L^{-2} T^{4} A^{2}right. ) |
12 |
| 1044 | The work done in carrying a charge ( q ) once round a circle of radius a with a charge ( Q ) at its centre is: A ( cdot frac{q Q}{4 pi varepsilon_{0} a} ) в. ( frac{q Q}{4 pi varepsilon_{0} a^{2}} ) c. ( frac{q}{4 pi varepsilon_{0} a} ) D. zero |
12 |
| 1045 | f some charge is given to a solid metallic sphere, the field inside remains zero and by Gauss’s law all the charge resides on the surface. Suppose now that Coulomb’s force between two charges varies as ( 1 / r^{3} . ) Then, for a charged solid metallic sphere A . field inside will be zero and charge density inside will be zero B. field inside will not be zero and charge density inside will not be zero c. field inside will not be zero and charge density inside will be zero D. field inside will be zero and charge density inside will not be zero |
12 |
| 1046 | Figure shows a capacitor made of two circular plates each of radius ( 12 mathrm{cm} ) and separated by ( 5.0 mathrm{cm} . ) The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15 A. (a) Calculate the capacitance and the rate of change of potential difference between the plates. ( (b) ) Obtain the displacement current across the plates. ( (c) ) Is Kirchhoffs first rule (junction rule) valid at each plate of the capacitor Explain. |
12 |
| 1047 | Five equal point charges with ( Q= ) ( 10 n C ) are located at ( x=2,4,5,10 ) and ( 20 m . ) If ( varepsilon_{0}=frac{10^{-9}}{36 pi} F / m, ) then the potential at the origin ( (x=0) ) is? A . ( 9.9 v ) B. ( 11.1 mathrm{v} ) c. ( 90 v ) D. ( 99 v ) E. 111 |
12 |
| 1048 | Four metallic plates each with a surface area of one side ( A, ) are placed at a distance ( d ) from each other. The two outer plates are connected to one point ( A ) and the two other inner plates to another point ( B ) as shown in the figure. Then the capacitance of the system is : ( A cdot frac{epsilon_{0} A}{d} ) в. ( frac{2 epsilon_{0} A}{d} ) c. ( frac{3 epsilon_{0} A}{d} ) D. ( frac{4 epsilon_{6} A}{d} ) |
12 |
| 1049 | When air is replaced by a dielectric medium of constant ( K ), the capacity of the condenser: A. increases ( K ) times B. increases ( K^{2} ) times C . remains unchanged D. decreases ( K ) times |
12 |
| 1050 | Two parallel plate air capacitors have the same separation. The plates of the first are squares of side ( 10 mathrm{cm} . ) The plates of the second are squares of side ( 20 mathrm{cm} . ) The ratio of their capacitance is : ( A cdot 2: ) B. 1: 2 ( c cdot 4: 1 ) D. 1: 4 |
12 |
| 1051 | Two point charges ( +9 q ) and ( +q ) are kept ( 16 mathrm{cm} ) apart. Where should a third charge ( Q ) be placed between them so that the system remains in equilibrium ( ? ) A. ( 24 mathrm{cm} ) from ( +9 q ) в. ( 12 mathrm{cm} ) from ( +9 q ) c. 24 cm from ( +q ) D. ( 12 mathrm{cm} ) from ( +q ) |
12 |
| 1052 | A voltmeter reads ( 4 V ) when connected to a parallel plate capacitor with air as a dielectric. When a dielectric slab is introduced between plates for the same configuration, voltmeter reads ( 2 V ) What is the dielectric constant of the material? A . 0.5 B. 2 c. 8 D. 10 |
12 |
| 1053 | The potential difference between the plates of a capacitor separated by ( 3 mathrm{mm} ) is ( 12.0 mathrm{V} ). Calculate the magnitude of ( mathrm{E} ) between the plates? |
12 |
| 1054 | (A) Estimate the speed with which electrons emitted from a heated emitter of an evacuated tube impinge on the collector maintained at a potential difference of ( 500 mathrm{V} ) with respect to the emitter. Ignore the small initial speeds of the electrons. The specific charge of the electron, i.e., its e/m is given to be ( 1.76 times 10^{11} C k g^{-1} ) (B) Use the same formula you employ in (a) to obtain electron speed for a collector potential of ( 10 mathrm{MV} ). Do you see what is wrong? In what way is the formula to be modified? |
12 |
| 1055 | The potential difference between two parallel plates is ( 10^{4} V . ) If the plates are separated by ( 0.5 mathrm{cm}, ) the force on an electron between the plates is : A . ( 32 times 10^{-13} N ) В. ( 0.32 times 10^{-13} N ) D. ( 3.2 times 10^{-13} ) ( N ) |
12 |
| 1056 | Two identical metal plates, separated by a distance d form a parallel plate capacitor. A metal sheet of thickness ( frac{a}{2} ) of the same area as that of either plate, is inserted between the plates. The ratio of the capacitance’s after the insertion of the sheet to that before insertion is: 2 ( mathbf{A} cdot sqrt{2}: 1 ) B. 2: c. 1: D. ( 1: sqrt{2} ) |
12 |
| 1057 | Two identical plates of different metals are joined to form a single plate whose thickness is double the thickness of each plate. If the coefficients of conductivity of each plate are 2 and 3 respectively, then the conductivity of the composite plate will be A. 5 B. 2.4 c. 1.5 D. 1.2 |
12 |
| 1058 | An electron that accelerates from a point near a collection of positive source charges toward a point near a collection of negative source charges experiences A. A decrease in electrical potential energy as it moves toward a region at a lower electric potential B. A decrease in electrical potential energy as it moves toward a region at a higher electric potential C. An increase in electrical potential energy as it moves toward a region at a lower electric potential D. An increase in electrical potential energy as it moves toward a region at a higher electric potential E. No change in electrical potential energy |
12 |
| 1059 | Equipotential surfaces A. are closer in regions of large electric fields compared to regions of lower electric fields B. will be more crowded near sharp edges of a conductor C . will always be equally spaced D. both (a) and (b) are correct |
12 |
| 1060 | Which of the material can be used as a dielectric? This question has multiple correct options A. Ceramics B. Woodd c. copper D. Aluminium |
12 |
| 1061 | In the electric field of charge ( Q ), another charge is carried from ( boldsymbol{A} ) to ( boldsymbol{B} . boldsymbol{A} ) to ( boldsymbol{C}, boldsymbol{A} ) to ( D ) and ( A ) to ( E ), then work done will be A. Minimum along path ( A B ). B. Minimum along path ( A D ). C. Minimum along path ( A E ). D. zero along all the paths |
12 |
| 1062 | Derive the expression for the capacitance of a parallel plate capacitore having plate area ( A ) and plate separation d. |
12 |
| 1063 | Two metallic spheres of radii ( 2 mathrm{cm} ) and ( 6 mathrm{cm} ) are given charge ( 3 times 10^{-2} mathrm{C} ) and ( 7 times 10^{-2} C, ) respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is |
12 |
| 1064 | Work done in moving an electric charge ( q ) in an electric field does not depend upon: A. Magnitude of the charge B. Potential difference between two points c. Mass of the particle D. All of these |
12 |
| 1065 | Which of the following units is not equivalent to Farad? A ( . C V^{2} ) в. ( J / V^{2} ) c. ( Q^{2} / J ) D. ( Q / V ) |
12 |
| 1066 | In scattering experiment, find the distance of closest approach, if a ( 6 M e V alpha- ) particle is used A ( .3 .2 times 10^{-16} m ) В. ( 2 times 10^{-14} mathrm{m} ) c. ( 4.6 times 10^{-15} mathrm{m} ) D. 3.2 ( times 10^{-15} mathrm{m} ) |
12 |
| 1067 | A highly conducting sheet of aluminium foil of negligible thickness is placed between the plates of a parallel plate capacitor. The foil is parallel to the plates at distance ( frac{d}{2} ) from positive plate where ( d ) is distance between plates. If the capacitance before the insertion of foil was ( 10 mu F ), its value after the insertion of foil will be: ( mathbf{A} cdot 20 mu F ) в. ( 10 mu F ) ( mathrm{c} .5 mu F ) D. zero |
12 |
| 1068 | Define the capacity of a condenser Derive an expression for the capacity of a parallel plate condenser. How can its capacity be increased? |
12 |
| 1069 | Three charges of ( +5 mu C ) are located at the comes of an equilateral triangle whose sides are ( 6 mathrm{cm} ) long. Find the potential at the midpoint of the base of the of the triangle. |
12 |
| 1070 | To bring a unit positive charge from infinity to a point in an electric field, some work has to done, which is called: A. potential energy B. electric potential c. electric field D. electric induction |
12 |
| 1071 | Assertion Coaxial cables make use of a dielectric between the two conducting lines. Reason dielectrics are good insulators. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 1072 | Four plates of same area of cross- section are joined as shown in figure. The distance between each plate is d. The equivalent capacity between ( A ) and B will be A ( cdot frac{2 epsilon_{0} A}{d} ) B. ( frac{epsilon_{0} A}{d} ) с. ( frac{3 epsilon_{0} A}{d} ) D. ( frac{3 epsilon_{0} A}{2 d} ) |
12 |
| 1073 | An isolated hollow metal sphere is electrically neutral (no excess charge) and supported on an insulating stand. A small amount of negative charge is suddenly placed at one point ( P ) on this metal sphere. If we check on this excess negative charge a few seconds later we will find one of the following possibilities: A. All of the excess charge remains right around P. B. The excess charge has distributed it self evenly over the outside surface of the sphere. C. The excess charge is evenly distributed over the inside and outside surface D. Most of the charge is still at point ( P ), but some will have spread over the sphere. |
12 |
| 1074 | A hollow metal sphere of radius ( 5 mathrm{cm} ) is charged such that the potential on its surface is ( 10 V . ) The potential at a distance of ( 2 mathrm{cm} ) from the centre of the sphere is: A. zero B. ( 10 V ) ( c .4 V ) D. ( 10 / 3 V ) |
12 |
| 1075 | If the plates of a parallel plate capacitor are not equal in area, then quantity of charge A. On the plates will be same but nature of charge will differ B. On the plates as well as nature of charge will be different c. on the plates will be different but nature of charge will be same D. As well as nature of charge will be same |
12 |
| 1076 | Which of the following statement(s) is/are correct? This question has multiple correct options A. Conductors are materials that allow the flow of electric current, whereas dielectric (insulators) do not B. The main difference between conductor and dielectric behavior is the amount of available free electrons C. Not all conductors have the same level of conductivity, just as not all insulators are resistant to electric current. D. Both A and B only |
12 |
| 1077 | Determine the electrostatic potential energy of a system consisting of two charges ( 7 mu C ) and ( -2 mu C ) separated by distance of ( 20 mathrm{cm} ) |
12 |
| 1078 | We increase the charge on the plate of a capacitor, it means A. increasing the capacitance B. increasing P.D. between plates c. decreasing P.D. between plates D. no change in field between plates |
12 |
| 1079 | Obtain an expression for equivalent capacitance when three capacitors ( C_{1}, C_{2} ) and ( C_{3} ) are connected in series. | 12 |
| 1080 | Q Type your question the center (point ( C ) ) of the equilateral triangle with charges at the corners? ( A ) B. ( c ) ( D ) |
12 |
| 1081 | Two thin wire rings each having a radius R are placed at a distance d apart with their axes coinciding. The charges on the two rings are ( +q ) and ( -q ) The potential difference between the centres of the two rings is – A ( . Q R / 4 pi varepsilon 0 d^{2} ) B. ( frac{Q}{2 pi_{c theta}}left[frac{1}{R}-frac{1}{sqrt{R^{2}+alpha^{2}}}right. ) c. zero D. ( frac{Q}{4 pi varepsilon_{0}}left[frac{1}{R}-frac{1}{sqrt{R^{2}+bar{d}^{2}}}right] ) |
12 |
| 1082 | Three charges ( -q, Q ) and ( -q ) are placed at equal distances on a straight line. If the total potential energy of the system of three charges is zero, then the ratio ( Q: q ) is : A . 1: 2 B . 2: 1 ( c cdot 1: 1 ) D. 1: 4 |
12 |
| 1083 | Capacity of a parallel plate condenser is ( 10 mu F ) when the distance between the plates is ( 8 mathrm{cm} . ) If the distance between the plates is reduced to ( 4 mathrm{cm}, ) its capacity will be: A. ( 10 mu F ) B. ( 15 mu F ) c. ( 20 mu F ) D. ( 40 mu F ) |
12 |
| 1084 | The distance between the plates of a parallel plate capacitor is ( d ). A metal plate of thickness ( d / 2 ) is placed between the plates. The capacitance would be then be A. Unchanged B. Initial c. zero D. Doubled |
12 |
| 1085 | Charge(Q) on capacitor( of capacitance C) and potential difference(V) across it are related as: A. ( Q=C times V ) в. ( Q=C / V ) c. ( Q=V / C ) D. Cannot be related |
12 |
| 1086 | At the moment ( t=0, ) an electron leaves one plate of a parallel-plate condenser with a negligible velocity. An accelerating voltage varying as ( boldsymbol{V}=boldsymbol{a} boldsymbol{t} ) where ( a ) is a constant is applied between the plates. The separation between the plates is ( l ). The velocity of the electron at the moment it reaches the opposite plate will be : ( ^{mathrm{A}}left(frac{2 e a l}{9 m}right)^{frac{1}{3}} ) ( ^{mathrm{B}}left(frac{3 e a l}{4 m}right)^{frac{1}{3}} ) ( ^{mathrm{c}}left(frac{4 e a l}{m}right)^{frac{1}{3}} ) ( left(frac{9 e a l}{2 m}right)^{frac{1}{3}} ) |
12 |
| 1087 | It is required to construct a ( 10 mu F ) capacitor which can be connected ( operatorname{across} ) a ( 200 V ) battery. Capacitors of capacitance ( 10 mu F ) are available but they can withstand only ( 50 V ) Design a combination which can yield the desired result |
12 |
| 1088 | When two capacitors are connected in parallel the resulting combination has capacitance ( 10 u F . ) The same capacitors when connected in series results in a capacitance ( 0.5 u F . ) The respective values of individual capacitors are A . ( 1.9 u F ) and ( 0.2 u F ) B . ( (8+2 sqrt{5}) u F ) and ( (2-2 sqrt{5}) u F ) c. ( (5+2 sqrt{5}) u F ) and ( (5-2 sqrt{5}) u F ) D. ( 12 u F ) and ( 17 u F ) E . ( 5 u F ) and ( 2 u F ) |
12 |
| 1089 | The parallel combination of two air filled parallel plate capacitors of capacitance ( mathrm{C} ) and ( mathrm{NC} ) is connected to a battery of voltage, ( V ). When the capacitors are fully charged, the battery is removed and after that a dielectric material of dielectric constant ( mathrm{K} ) is placed between the two plates of the first capacitor. The new potential difference of the combined system is? A ( cdot frac{V}{K+n} ) в. ( V ) c. ( frac{(n+1) V}{(K+n)} ) D. ( frac{n V}{K+n} ) |
12 |
| 1090 | What is the field in the cavity if a conductor having a cavity is charged? Does the result depend on the shape and size of cavity or conductor? |
12 |
| 1091 | 64 identical spheres of charge ( q ) and capacitance ( C ) each are combined to form a large sphere. The charge and capacitance of the large sphere is: ( A cdot 64 q, c ) B. 169, 4C ( c cdot 649,4 c ) D. ( 169,64 mathrm{c} ) |
12 |
| 1092 | Two conducting plates ( x ) and ( y ) each of area ( A ) are placed parallel to each other at a small separation ( boldsymbol{d} . boldsymbol{X} ) is given a charge ( 3 q ) and ( Y ) is given a charge ( q ) The potential difference between the plates is A ( cdot frac{q d}{2 varepsilon_{0} A} ) в. ( frac{q d}{varepsilon_{0} A} ) c. ( frac{3 q d}{2 varepsilon_{0} A} ) D. ( frac{2 q d}{varepsilon_{0} A} ) |
12 |
| 1093 | Two capacitors connected in parallel having the capacities ( C_{1} ) and ( C_{2} ) are given ‘ ( q^{prime} ) charge, which is distributed among them. The ratio of the charge on ( C_{1} ) and ( C_{2} ) will be : A ( cdot frac{C_{1}}{C_{2}} ) в. ( frac{C_{2}}{C_{1}} ) ( mathbf{c} cdot C_{1} C_{2} ) D. ( frac{1}{C_{1} C_{2}} ) |
12 |
| 1094 | toppr ०६ Q Type your question In tigure. I nen the Key ( mathbf{K} ) Is pressed to complete the circuit. Finally the net charge on upper plate and net charge the circuit. Finally the net charge on upper plate and net charge on lower plate of capacitor ( C ) is positive. Reason : In a parallel plate capacitor |
12 |
| 1095 | The capacity of parallel plate capacitor depends on: A. metal used to make plates B. thickness of plate c. potential applied across the plate D. area of plate |
12 |
| 1096 | In a series combination of two capacitances ( C^{prime} ) and ( C(C>C) ) (as shown in the circuit) A. C’ stores more energy than ( C ) B. ( C ) stores more energy than ( C^{prime} ) c. potential difference across ( C ) is more than that across ( C ) D. potential difference across ( C^{prime} ) is less than that across ( C ) |
12 |
| 1097 | An infinite cylinder of radius ( r_{0} ) carrying linear charge density ( lambda ). The equation of the equipotential surface for this cylinder is ( mathbf{A} cdot r=r_{0} e^{pi varepsilon_{0}left[V(r)+Vleft(r_{0}right)right] lambda} ) B . ( r=r_{0} e^{2 pi varepsilon_{0}}left[V(r)-Vleft(r_{0}right)right] lambda^{2} ) C . ( r=r_{0} e^{-2 pi varepsilon_{0}}left[V(r)-Vleft(r_{0}right)right] / lambda ) D. ( r=r_{0} e^{-2 pi varepsilon_{0}leftlfloor V(r)-Vleft(r_{0}right) backslash lambdaright.} ) |
12 |
| 1098 | If the distance between the place of a parallel plate capacity ( 10 mu F ) is doubled, then new capacity will be: A ( .5 mu F ) в. ( 20 mu F ) c. ( 10 mu F ) D. ( 15 mu F ) |
12 |
| 1099 | Electric potential due to a point charge ( q ) at a distance ( r ) from is given by A ( cdot V=frac{q}{4 pi epsilon_{0}} ) B. ( V=frac{q}{4 pi epsilon_{0} r^{2}} ) ( mathbf{c} cdot v=frac{q}{4 pi epsilon_{0} r} ) D. ( v=frac{q^{2}}{4 pi epsilon_{6} r} ) |
12 |
| 1100 | A solid copper sphere has a charge of ( +mathrm{Q} ) on it. Where on the sphere does the charge reside? A. ( +Q ) at the center of the sphere B. ( mathrm{Q} / 2 ) at the center of the sphere and ( mathrm{Q} / 2 ) on the outer surface c. ( mathrm{Q} ) at the center of the sphere and ( +2 mathrm{Q} ) on the outer surface D. ( + ) Q on the outer surface E. The charge is spread evenly throughout the sphere |
12 |
| 1101 | A regular hexagon of side ( 10 mathrm{cm} ) has a charge ( 5 mu C ) at each of its vertices. Calculate the potential at the centre of the hexagon. ( mathbf{A} cdot 5.8 times 10^{6} V ) В. ( 3.2 times 10^{6} V ) c. ( 9.3 times 10^{6} V ) D. ( 2.7 times 10^{6} V ) |
12 |
| 1102 | The electric potential ( V ) at any point ( P(x, y, z) ) in space is given by ( V= ) ( 4 x^{2} V . ) The electric field at the point ( (1 m, 2 m) ) is: A . ( -8 i ) B. ( 8 hat{i} ) ( mathrm{c} cdot-16 hat{i} ) D. ( 16 hat{i} ) |
12 |
| 1103 | Two large vertical and parallel metal plates having a separation of ( 1 mathrm{cm} ) are connected to a DC voltage source of potential difference ( X . ) A proton is released at rest midway between the two plates. It remains at rest in the air then ( X ) is: A ( cdot 1 times 10^{-5} V ) В. ( 1 times 10^{-7} V ) c. ( 1 times 10^{-9} V ) D. ( 1 times 10^{-10} V ) |
12 |
| 1104 | Assertion A charged metallic sphere when brought nearer to an uncharged metallic sphere, it may exert an attractive force, but once they touch each other, they exert repulsive force. Reason The net electric field Inside a conductor is zero. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 1105 | A uniform vertical field ( E ) is established between two parallel plates. In this field, a small conducting sphere of mass ( boldsymbol{M} ) is suspended from a string of length ( l ). If the sphere is given a charge ( +q ) (statcoulomb) and if lower plate is charged positively, the period of the simple pendulum is: A ( .2 pi sqrt{l / g} ) ( ^{mathrm{B}} cdot 2 pi sqrt{frac{l}{left(g+frac{q E}{m}right)}} ) c. [ sqrt[2 pi]{frac{l}{left(g-frac{q E}{m}right)}} ] ( D ) [ sqrt{frac{l}{left(frac{q E}{m}-gright)}} ] |
12 |
| 1106 | Four charges, all of same magnitude are placed at the four corners of a square. At the centre of the square, the potential is ( V ) and the field is ( E . B y ) suitable choices of the signs of the four charges, which of the following can be obtained? This question has multiple correct options A. ( V=0, E=0 ) B. ( V=0, E neq 0 ) c. ( V neq 0, E=0 ) D. ( V neq 0, E neq 0 ) |
12 |
| 1107 | f a proton is released from rest at point p in the diagram, what will it do? A. Move to the right B. Move to the left c. Move toward the top of the screen D. Move toward the bottom of the screer |
12 |
| 1108 | Two fixed, equal, positive charges, each of magnitude ( 5 times 10^{-5} C ) are located at point ( A ) and ( B ) separated by a distance ( 6 m . ) An equal and opposite charge moves towards them along the line COD, the perpendicular bisector of the line ( A B . ) The moving charge, when it reaches the point ( C ) at a distance of ( 4 m ) from ( O, ) has a kinetic energy of 4 joules. Calculate the distance of the farthest point ( D ) which the negative charge will reach before returning towards ( C ) |
12 |
| 1109 | In the uniform electric field shown in figure, ( boldsymbol{V}_{boldsymbol{A}}-boldsymbol{V}_{boldsymbol{D}} ) is : ( A cdot 5 V ) B. ( 10 V ) ( c .20 V ) D. ( 0 V ) |
12 |
| 1110 | In the figure ( Q-26 ) the potential at ( A ) is when the potential at B is zero. |
12 |
| 1111 | Two point charges ( Q ) and ( -Q / 4 ) are separated by | 12 |
| 1112 | If we introduce a large thin metal plate between two points charges, what will happen to the force between the charges? |
12 |
| 1113 | The equivalent capacity between the points ‘A’ and ‘B’ in the following figure will be: ( A cdot 9 mu F ) в. ( 1 mu F ) c. ( 4.5 mu F ) D. ( 6 mu F ) |
12 |
| 1114 | Two capacitors are connected as shown in figure below. If the equivalent capacitance of the combination is ( 4 mu F ) (i) Calculate the value of ( C ) (ii) Calculate the charge on each capacitor. (iii) What will be the potential drop across each capacitor? |
12 |
| 1115 | Two insulated charged spheres of radii ( R_{1} ) and ( R_{2} ) having charges ( Q_{1} ) and ( Q_{2} ) respectively are connected to each other, then there is: B. an increase in the energy of the system C. always a decrease in the energy of the system D. a decrease in energy of the system unless ( q_{1} R_{2}=q_{2} R_{1} ) |
12 |
| 1116 | Two spherical conductors ( A ) and ( B ) of radii ( 1 mathrm{mm} ) and ( 2 mathrm{mm} ) separated by a distance of ( 5 mathrm{cm} ) and are uniformly charged. If the spheres are connected by a conducting wire then in equilibrium condition, the ratio of the magnitude of the electric fields at the surfaces of spheres ( A ) and ( B ) is: A . 4: 1 B. 1: 2 c. 2: 1 D. 1: 4 |
12 |
| 1117 | Five charges of magnitudes ( 24 mu C,-25 mu C, 3 mu C,-7 mu C ) and ( 28 mu C ) are situated along the circumference of a circle of radius ( 3 mathrm{cm} ). Then the potential at the centre of the circle is A ( .54 times 10^{7} V ) В. ( 45 times 10^{6} V ) ( mathbf{c} cdot 72 times 10^{6} V ) ( mathbf{D} cdot 69 times 10^{5} V ) |
12 |
| 1118 | Two points ( mathbf{P} ) and ( mathbf{Q} ) are maintained at the potentials of ( 10 mathrm{V} ) and ( -4 mathrm{V} ) respectively. The work done in moving 100 electrons from ( mathbf{P} ) to ( mathbf{Q} ) is : В ( cdot 9.60 times 10^{-17} mathrm{J} ) c. ( -2.24 times 10^{-16} mathrm{J} ) D ( .2 .24 times 10^{-16} mathrm{J} ) |
12 |
| 1119 | Dielectric constant, property of an electrical insulating material (a dielectric) equal to A. the ratio of the capacitance of a capacitor filled with the given material to the capacitance of an identical capacitor in a vacuum without the dielectric material. B. the ratio of the capacitance of a capacitor filled with the given material to the capacitance of an identical capacitor in a vacuum with the dielectric material c. the capacitance of a capacitor filled with the given material D. none of the above |
12 |
| 1120 | An equipotential line and a line of force are: A. perpendicular to each other B. parallel to each other c. in any direction D. at an angle of ( 45^{circ} ) |
12 |
| 1121 | The charges of ( 2 mu c, 4 mu c ) and ( 6 mu c ) are placed at the corner ( A, B quad ) and respectively of a square ( A B C D ) of side ( 0.2 m ) calculate the work done to transfer a charge of ( 2 mu c ) from ( D ) to the center of the square. |
12 |
| 1122 | what is the potential difference between two points, if 2 J of work must be done to move a ( 4 mathrm{mC} ) charge from one point to another is: A. ( 50 v ) B. 500 ( c cdot 5 v ) D. 5000 |
12 |
| 1123 | What is the geometrical shape of equipotential surface due to a single isolated charge? | 12 |
| 1124 | In the situation shown in figure, what should be the relation between ( Q ) and ( q ) so that electric potential at centre of the square is zero: A. ( Q=q ) в. ( Q=3 q ) c. ( Q=2 q ) D. ( Q=-3 q ) |
12 |
| 1125 | Define equipotential surface. | 12 |
| 1126 | Equipotential surfaces associated with an electric field which is increasing in magnitude along the x-direction are: A. Planes parallel to yz-plane B. Planes parallel to xy-plane c. Planes parallel to xz-plane D. coaxial cylinders of increasing radii around the x-axis |
12 |
| 1127 | Which of the following statement is true about the relation between electric field and potential? A. Electric field in the direction in which the potential decreases steepest B. Magnitude of electric field is given by the change in the magnitude of potential per unit displacement normal to the equipotential surface at that point. C. In the region of strong electric field, equipotentia D. Both the statements (a) and (b) are correct. |
12 |
| 1128 | The Sl unit of electric potential is A. ( V m^{-1} ) в. ( C ) c. ( N C^{-1} ) D. ( V ) |
12 |
| 1129 | Two charges ( 5 times 10^{-8} C ) and ( -3 x ) ( 10^{-8} C ) are located ( 16 mathrm{cm} ) apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero. |
12 |
| 1130 | The plates of parallel-plate condenser are being moved away with velocity v. If the plate separation at any instant of time is ( d ) then the rate of change of capacitance with time is proportional to A ( cdot d^{2} ) B. ( d ) ( c cdot d^{-2} ) D. ( d^{-1} ) |
12 |
| 1131 | Within a spherical charge distribution of charge density ( rho(r), ) N equipotential surfaces of potential ( V_{0}, V_{0}+ ) ( boldsymbol{Delta} boldsymbol{V}, boldsymbol{V}_{0}+boldsymbol{2} boldsymbol{Delta} boldsymbol{V}, ldots . ., boldsymbol{V}_{0}+ ) ( N Delta V(Delta V>0), ) are drawn and have increasing radii ( r_{0}, r_{1}, r_{2}, dots . . r_{N} ) respectively. If the difference in the radii of the surfaces is constant for all values of ( V_{0} ) and ( Delta V ) then : A ( cdot rho(r)= ) constant B. ( rho(r) propto frac{1}{r^{2}} ) c. ( rho(r) propto frac{1}{r} ) D. ( rho(r) propto 1 ) |
12 |
| 1132 | Two circular coils ( P ) and ( Q ) are kept close to each other, of which coil ( boldsymbol{P} ) carries a current. If coil ( boldsymbol{P} ) is moved towards ( Q, ) will some current be induced in coil ( Q ) ? Give the reason for your answer and name the phenomenon involved. |
12 |
| 1133 | Illustrate a condition in which : Electric field is not zero but potential is zero |
12 |
| 1134 | An electron initially at rest is accelerated through a potential difference of one volt. The energy gained by the electron is: A. 15 B . ( 1.6 times 10^{-19} mathrm{J} ) ( mathbf{c} cdot 10^{-19} J ) D. None of these |
12 |
| 1135 | Where do charges reside in the case of a charged conductor? A. Inside the conductor B. on the outer surface of the conductor c. on the inner surface of the conductor D. Anywhere outside the conductor |
12 |
| 1136 | The distance between the plates of a condenser is reduced to ( frac{1}{4} t h ) and the space between the plates is filled up by a medium of dielectric constant ( mathrm{K}(2.8) ). The capacity is increased by : A. 5.6times B. 11.2times c. 22.4 times D. 44.8 times |
12 |
| 1137 | Evaluate potential energy per ion for NaCl crystal. Use inter atomic spacing ( 2.82 times 10^{10} m ) В. ( 2.67 times 10^{-19} mathrm{J} ) ( mathbf{c} cdot 5.67 times 10^{-19} J ) D. none |
12 |
| 1138 | Find the dimensions and units of ( varepsilon_{0} ? ) | 12 |
| 1139 | A parallel plane capacitor ( C ) with plates of unit area and separation ( d ) is filled with a liquid of dielectric constant ( k= ) 2. The level of liquid is ( frac{u}{3} ) initially. Suppose the liquid level decreases at a constant speed ( v ), the time constant as a function of time ( t ) is A ( frac{6 varepsilon_{0} R}{5 d+3 v} ) B. ( frac{(15 d+9 v t) varepsilon_{0} R}{2 d^{2}-3 d u t-9 v^{2} t^{2}} ) c. ( frac{6 pi varepsilon_{0} R}{5 d-3 v} ) D. ( frac{(15 d-9 v t) varepsilon_{0} R}{2 d^{2}+3 d v t-9 v_{2 t^{2}}} ) |
12 |
| 1140 | Four equal charges q each are placed at four corners of a square of side a each. Work done in carrying a charge q from its centre to infinity is: A. zero В. ( frac{2 q^{2}}{pi varepsilon_{0} a} ) c. ( frac{sqrt{2} q^{2}}{pi varepsilon_{0} a} ) D. ( frac{q^{2}}{2 pi varepsilon_{0} a} ) |
12 |
| 1141 | Four identical charges are placed at the points (1,0,0),(0,1,0),(-1,0,0) and ( (0 .-1,0) ) A. The potential at the origin is zero B. The field at the origin is zero c. The potential at all points on the z-axis, other than the origin, is zero D. The potential at all points on the z-axis, other than the origin acts along the z-axis |
12 |
| 1142 | A parallel plate capacitor is charged and then the battery is disconnected, When the plates of the capacitor are brought closer, then This question has multiple correct options A. energy stored in the capacitor decreases B. the potential difference between the plates decreases c. the capacitance increases D. the electric field between the plates decreases |
12 |
| 1143 | Two charges ( 5 times 10^{-8} C ) and ( -3 x ) ( 10^{-8} C ) are located ( 0.16 m ) apart. At what point(s) on the line joining the two charges in the electric potential zero? Take the potential at infinity to be zero. |
12 |
| 1144 | Define dielectric constant of a medium. What is its ( S . I . ) unit? |
12 |
| 1145 | A particle A has charge +q and a particle B has a charge +9q with each of them having the same mass m.If both the particles are allowed to all from rest through the same potential difference, then the ratio of their speed is A .1: 2 B. ( 1: sqrt{3} ) c. ( 1: 2 sqrt{2} ) D. none of these |
12 |
| 1146 | If a positive charge is shifted from a low potential region to a high potential region, the electric potential energy: A. Increases B. Decreases c. Remains unchanged D. May increase or decrease |
12 |
| 1147 | Electrical potential at the centre of a charged conductor is: A . zero B. twice as that on the surface c. half of that on the surface D. same as that on the surface |
12 |
| 1148 | Charges are placed on the vertices of a square as shown. Let ( vec{E} ) be the electric field and V the potential at the centre. If the charges on ( A ) and ( B ) are interchanged with those on D and respectively, then A. ( bar{E} ) changes, v remains unchanged B. ( bar{E} ) remains unchanged, v changed c. both ( vec{E} ) and ( v ) change D. ( vec{E} ) and v remain unchange |
12 |
| 1149 | Assertion The dielectric constant is a number without dimensions. Reason Dielectric constant is a ratio. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 1150 | In a regular polygon of ( n ) sides, each corner is at a distance ( r ) from the centre. Identical charges are placed at ( (n-1) ) corners. At the centre, the magnitude of intensity is ( mathrm{E} ) and the potential is V.The ratio V/E is ( A cdot r n ) B. ( r(n-1) ) ( c cdot(n-1) / r ) ( D cdot r(n-1) / n ) |
12 |
| 1151 | Positive charge flow from a body at to a body at Fill in the blanks. A. higher potential, lower potential B. lower potential, higher potential c. higher charge, , lower charge D. higher force, lower force |
12 |
| 1152 | 14 field intensity at the center of a square having fixed point charges at their vertices as shown in figure are zero. Reason If electric potential at a point is zero |
12 |
| 1153 | The insertion of a dielectric between the plates of a parallel-plate capacitor always A. increases its capacitance B. decreases its capacitance c. remains same its capacitance D. none of the above |
12 |
| 1154 | Find the relation between potential difference V and separation between the plates z: ( ^{mathrm{A}} cdot_{V^{2}}=frac{K_{z}left(z_{0}-zright)^{2}}{A varepsilon_{0}} ) B. ( V^{2}=frac{2 K_{z}left(z_{0}-zright)^{2}}{A varepsilon_{0}} ) c. ( V^{2}=frac{4 K_{z}left(z_{0}-zright)^{2}}{A varepsilon_{0}} ) D. ( V^{2}=frac{K_{z}left(z_{0}-zright)^{2}}{4 A varepsilon_{0}} ) |
12 |
| 1155 | Four identical parallel conductors, carrying charges ( Q,-2 Q, 3 Q ) and ( 4 Q ) are placed as shown in the figure. The plates carrying charges ( Q ) and ( 4 Q ), are connected through a switch, as shown. The amount of charge flowing through the switch, after closing it is found to be ( n Q . ) Find ( n ) |
12 |
| 1156 | A dielectric slab of thickness dis inserted in a parallel plate capacitor where negative plate is at ( x=0 ) and positive plate is at ( x=3 d . ) The slab is equidistant from the plates. The capacitor is given some charge. As ( x ) goes from 0 to ( 3 d ) This question has multiple correct options A. The magnitude of electric field remains the same B. The direction of electric field remain the same c. The electric potential increases continuously. D. The electric potential increase at first then decrease and again increase. |
12 |
| 1157 | Two identical particles of mass ( m ) carry charge ( Q ) each. Initially one is at rest on a smooth horizontal plane and the other is projected along the plane directly towards first particle from a large distance with speed ( v ). The closest distance of approach will be A ( cdot frac{1}{4 pi varepsilon_{0}} frac{Q^{2}}{m v} ) B. ( frac{1}{4 pi varepsilon_{0}} frac{4 Q^{2}}{m v} ) ( ^{mathbf{C}} frac{1}{4 pi varepsilon_{0}} frac{4 Q^{2}}{m v^{2}} ) ( ^{mathrm{D}} frac{1}{4 pi varepsilon_{0}} frac{2 Q^{2}}{m v^{2}} ) |
12 |
| 1158 | If a unit charge is taken from one point to another over an equipotential surface, then A. work is done on the charge B. work is done by the charge c. work on the charge is constant D. no work is done |
12 |
| 1159 | (a) Distinguish with the help of a suitable diagram, the difference in the behaviour of a conductor and a dielectric placed in an external electric field. How does polarised dielectric modify the original external field? (b) A capacitor of capacitance ( C ) is charged fully by connecting it to a battery of emf E. It is then disconnected from the battery. If the separation between the plates of the capacitor is now doubled, how will the following change? (i) Charge stored by the capacitor. (ii) Field strength between the plates. (iii) Energy stored by the capacitor. Justify your answer in each case. |
12 |
| 1160 | Figure shows equipotential surfaces concentric at ‘O’ the magnitude of electric fields at distance r(in meter) measured from A ( cdot frac{9}{r^{2}}left(V m^{-1}right) ) в. ( frac{6}{r^{2}}left(V m^{-1}right) ) c. ( frac{2}{r^{2}}left(V m^{-1}right) ) D. ( frac{16}{r^{2}}left(V m^{-1}right) ) |
12 |
| 1161 | Two points charges ( 4 mu C ) and ( -2 mu C ) are separated by a distance of ( 1 mathrm{m} ) in air. ( mathrm{At} ) what point in between the charges and on the line joining the charges, is the electric potential zero? A. In the middle of the two charges B. ( 1 / 3 m ) from ( 4 mu C ) c. ( 1 / 3 m ) from ( -2 mu C ) D. Nowhere the potential is zero |
12 |
| 1162 | A parallel plate capacitor consists of two circular plates each of radius ( 12 mathrm{cm} ) and separated by ( 5.0 m m . ) The capacitor is being charged by an external source. The charging current is constant and is equal to ( 0.15 A ). The rate of change of potential difference between the plates will be : A. ( 8.173 times 10^{7} V / s ) В . ( 7.817 times 10^{8} V / s ) C ( .1 .873 times 10^{9} mathrm{V} / mathrm{s} ) D. ( 3.781 times 10^{10} V / s ) |
12 |
| 1163 | The ratio of momentum of an electron and an alpha particle which are accelerated from rest by potential difference of ( 100 mathrm{V} ) is: A ( cdot sqrt{frac{m_{alpha}}{m_{e}}} ) В. ( sqrt{frac{m_{e}}{m_{alpha}}} ) c. ( frac{2 m_{e}}{m_{alpha}} ) D. ( sqrt{frac{m_{e}}{2 m_{alpha}}} ) |
12 |
| 1164 | Two charges ( 2 mu C ) and ( -2 mu C ) are placed at points ( A ) and ( B 6 mathrm{cm} ) apart. (a) Identify an equipotential surface of the system. (b) What is the direction of the electric field at every point on this surface? |
12 |
| 1165 | Charges ( -boldsymbol{q}, boldsymbol{Q} ) and ( -boldsymbol{q} ) are placed at an equal distance on a straight line. If the total potential energy of the system of three charges is zero, then find the ratio ( boldsymbol{Q} / boldsymbol{q}: ) A. ( 1 / 2 ) в. ( 1 / 4 ) ( c cdot 2 / 3 ) D. ( 3 / 4 ) |
12 |
| 1166 | Consider a parallelogram ( A B C D, ) with angle ( angle B=120^{circ} . ) A charge ( +Q ) placed at the corner ( A ) produces field ( E ) and potential ( V ) at corner ( D ). If we now add charges ( -2 Q ) and ( +Q ) at corners ( B ) and ( C ) respectively, the magnitude of field and potential at ( D ) will become respectively ( ^{A} cdot frac{sqrt{3}}{2} E, V ) в. ( frac{sqrt{3}}{2} E, ) о ( c . E, 0 ) D. ( frac{E}{sqrt{2}}, frac{V}{sqrt{2}} ) |
12 |
| 1167 | Two electrons separated by a distance ( r ) experiences a force ( F ) between them. The force between a proton and a single joined helium atom separated by a distance ( 2 r ) is A ( .4 F ) в. ( 2 F ) c. ( F / 2 ) D. ( F / 4 ) |
12 |
| 1168 | Net Capacitance of three identical in series is ( 1 mu F ). What will be their net capacitance, if connected in parallel? Find the ratio of energy stored in the two configurations, if they are both connected to the same source. |
12 |
| 1169 | What should be the charge on a sphere of radius ( 2 mathrm{cm} ) so that when it is brought in contact with another sphere of radius ( 5 mathrm{cm} ) carrying a charge of ( 10 mu C, ) there is no transfer of charge between the spheres? |
12 |
| 1170 | From a supply of identical capacitors rated ( 8 mu F, 250 V ) the minimum number of capacitors required to form a composite of ( 16 mu F, 1000 V ) is ( A cdot 2 ) B. 4 ( c cdot 16 ) D. 32 |
12 |
| 1171 | In the circuit shown the current through the ( 4 Omega ) resistor is 1 amp when the points ( P ) and ( M ) are connected to a d.c voltage source. The potential difference between the points ( M ) and ( N ) is: A. 0.5 volt B. 3.2 volt c. 1.5 volt D. 1.0 volt |
12 |
| 1172 | Assertion Dielectric materials can be solids, liquids, or gases. Reason Usage of dielectric depends on the application i.e.Industrial coatings such as parylene provide a dielectric barrier between the substrate and its environment. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
12 |
| 1173 | ( frac{frac{pi}{4}}{frac{pi}{4}} ) | 12 |
| 1174 | A solid sphere of radius ( boldsymbol{R} ) has a charge ( +2 Q . ) A hollow spherical shell of radius ( 3 R ) placed concentric with the first sphere has net charge ( -Q . ) If the inner sphere is earthed, what will be the charge on it? A ( cdot frac{2 Q}{3} ) B. ( frac{-6}{3} ) c. ( frac{Q}{3} ) D. ( frac{-2 Q}{3} ) |
12 |
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