We provide magnetic effects of electric current practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on magnetic effects of electric current skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.

#### List of magnetic effects of electric current Questions

Question No | Questions | Class |
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1 | In an electrical circuit two resistors of 2 ( Omega ) and ( 4 Omega ) respectively are connected in series to a ( 6 mathrm{V} ) battery. The heat dissipated by the ( 4 Omega ) resistor in 5 s will be A . 5 J B. 10 c. 20 D. 30 |
10 |

2 | Choose the correct statement from the following: This question has multiple correct options A. Soft iron is used as the core of transformer. B. The strength of an electromagnet increases when the current in the coil is increased. C. An electric bell works on the principle of an electromagnet. D. The direction of a magnetic field due to current in a straight conductor is obtained using right hand grip rule. |
10 |

3 | Heat produced in a resistor when current is passed through it depends upon- A. Current only B. Time only c. Current and time D. None of these |
10 |

4 | Alternating current is one which changes in its : A. direction B. magnitude c. magnitude and direction both D. none |
10 |

5 | The current in an AC circuit is represented by ( i=5 sin left(300 t-frac{pi}{4}right) ) where, t is in seconds and current is in amperes. Then, the frequency of AC is ( A cdot 50 mathrm{Hz} ) B. 47.75 Hz ( c cdot 30 ) Нz D. 25 Hz |
10 |

6 | The element of electric heater is made of A. Iron B. Nichrome c. copper D. Gold |
10 |

7 | A bulb is connected to an ideal battery of emf ( 10 mathrm{V} ) so that the resulting current is ( 10 mathrm{mA} ). When the bulb is connected to ( 220 mathrm{V} ) mains (ideal), the current is 50 mA. choose the correct alternative A. the resistance of the bulb is 1 k ohm and in the second case, it is ( 4.4 mathrm{k} ) ohm B. it is not possible since ohm’s law is not followed c. the increase in resistance is due to heating of the filament of the bulb when it is connected to ( 220 mathrm{v} ) main D. none of these |
10 |

8 | Write daily life uses of heating effect of electric current | 10 |

9 | Which of the following does not electrical power in circuit? ( mathbf{A} cdot I^{2} R ) B . ( I R^{2} ) c. ( V I ) D. ( frac{V^{2}}{R} ) |
10 |

10 | One unit of electric energy is equal to: A. One kilowatt hour B. one watt hour c. 100 Joules D. none of these |
10 |

11 | Why are transmission losses so crucial that electrical power systems are designed to work on Alternating currents? A. Electrical power systems are not very efficient for transmission of power B. It is a practice to use AC over DC C. AC networks are easier to handle than DC Networks and constructional setup cost is really high in DC D. since, power stations are very far away from destinations, transmission has to be done over long distances and losses add up over the distance |
10 |

12 | Either a fuse or a circuit-breaker can be used to protect electrical cables from large currents that could cause overheating. When a fuse is used, where should it be connected, and when a circuit-breaker is used, where should it be connected? A. Position of fuse ( -X ), Position of circuit-breaker ( -X ) B. Position of fuse – ( X ), Position of circuit-breaker – ( Y ) c. Position of fuse ( -Y ), Position of circuit-breaker ( -X ) D. Position of fuse – ( Y ), Position of circuit-breaker – ( Y ) |
10 |

13 | An alternating voltage ( boldsymbol{E}= ) ( 200 sqrt{2} sin (100 t) ) is connected to 1 microfarad capacitor through ( A C ) ammeter. The reading of ammeter shall be ( A cdot 10 m A ) B. ( 20 mathrm{mA} ) c. ( 40 mathrm{mA} ) D. ( 80 mathrm{mA} ) |
10 |

14 | Define alternating current and explain working of the device which produces it. Draw labelled diagram. Describe the change in direction of current. |
10 |

15 | ( 4 sqrt{2} m ) and breadth ( 4 m ) carrying a current of ( 5 A ) in the anti-clockwise direction is placed in the xy-plane. The magnitude of the magnetic induction field vector ( B ) at the intersection of the diagonal is ( left(U s e u_{0}=4 pi xright. ) ( left.10^{-7} N A^{-2}right) ) A ( .1 .2 times 10^{-6} T ) B . ( 1.2 times 10^{-5} T ) c. ( 2.4 times 10^{-6} T ) D. ( 2.4 times 10^{-5} T ) E ( .1 .2 times 10^{-7} T ) |
10 |

16 | State some characteristics of magnetic field due to a Current through a Straight Conductor. |
10 |

17 | Find the total current that passes through the circuit. Find the heat generated across the each resistor: |
10 |

18 | What is the voltage of the electricity that is generally supplied to a house? ( mathbf{A} cdot 400 V ) B. ( 200 mathrm{V} ) ( mathbf{c} cdot 220 V ) D. ( 260 V ) |
10 |

19 | An electric bulb is rated at ( 220 mathrm{V}, 100 mathrm{W} ) What safe current can be passed through it ? ( mathbf{A} cdot 2 cdot 20 A ) B . ( 3.50 A ) c. ( 0.45 A ) D. ( 0.50 A ) |
10 |

20 | A lamp is marked ( 60 mathrm{W}, 220 mathrm{V} ). If it operates at ( 200 mathrm{V} ), the rate of consumption of energy will A. decrease B. increase c. remain unchanged D. first increase then decrease |
10 |

21 | A magnetic field lines due to a straight wire carrying a current are A. Straight B. Circular c. Parabolic D. Elliptical |
10 |

22 | Two horizontal metal plates having a potential difference of ( 800 mathrm{V} ) are ( 0.02 mathrm{m} ) apart. A particle of mass ( 1.92 times ) ( 10^{-15} mathrm{kg} ) is suspended in equilibrium between the plates. Ife is the elementry charge, then charge on the particle is: ( A ) B . 3 e c. ( 6 mathrm{e} ) D. ( 8 mathrm{e} ) |
10 |

23 | How should the electric lamps in a building be connected? |
10 |

24 | Assertion An alternating current does not show any magnetic effect. Reason Alternating current does not vary with time 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 |
10 |

25 | f current ( boldsymbol{I}_{1}=mathbf{3} boldsymbol{A} sin omega boldsymbol{t} ) and ( boldsymbol{I}_{2}= ) ( 4 A cos omega t, ) then ( I_{3} ) is A ( cdot 5 a sin left(omega t+53^{circ}right) ) B. ( 5 a sin left(omega t+37^{circ}right) ) c. ( 5 a sin left(omega t+45^{circ}right) ) D. ( 5 a sin left(omega t+30^{circ}right) ) |
10 |

26 | An electric kettle is rated ( 2.5 k W, 250 V ) What is the cost of running the kettle for two hours at Rs. 5.40 per unit? A. ( R s .17 .00 ) B. ( R s .27 .00 ) c. ( R s .26 .00 ) D. ( R s .16 .20 ) |
10 |

27 | An electric iron uses a power of ( 1320 W ) when set to higher temperature. If set to lower temperature one third of higher temperature current is used. If iron is connected to a potential of ( 220 V ), then power used to lower temperature is ( mathbf{A} cdot 220 W ) в. ( 440 mathrm{W} ) c. ( 660 W ) D. ( 880 W ) |
10 |

28 | A given resistor cannot carry currents exceeding 20 A, without exceeding its maximum power dissipation ratings. By forced air cooling suppose that we increase the rate at which heat can be carried by a factor of ( 2 . ) Now the maximum current that the resistor can carry is A. ( 10 A ) В. ( 20 sqrt{2} A ) ( c cdot 30 sqrt{2} A ) D. ( 40 A ) |
10 |

29 | Choose the incorrect statement: A. Flemings right-hand rule is a simple rule to know the direction of induced current B. The right-hand thumb rule is used to find the direction of magnetic fields due to current carrying conductors C. The difference between the direct and alternating currents is that the direct current always flows in one direction, whereas the alternating current reverses its direction periodically D. In India the AC changes direction after every ( frac{1}{50} ) second |
10 |

30 | The potential of neutral wire is: A. ov B. 300V c. ( 220 v ) D. 1000v |
10 |

31 | Name the switch/switches to be closed so as to light all the three lamps ( A cdot 2 ) and B. 1 and 3 c. only 2 D. 1 and |
10 |

32 | Commonly used heating element are made of: A. Iron B. Manganese c. Nichrome D. Platinum |
10 |

33 | Calculate the value of current ( i ), in the given electric circuit: |
10 |

34 | n the circuit shown in the figure, find the current in ( 45 Omega ) ugure, una tne current in A. ( 4 A ) В. 2.5 ( c .2 A ) D. None of these |
10 |

35 | A coil of self inductance ( 10 m H ) and resistance ( 0.1 Omega ) is connected through a switch to a battery of internal resistance ( 0.9 Omega ) After the switch is closed, the time taken for the current to attain ( 80 % ) of the saturation value is : (Take ( l n 5=1.6) ) A . ( 0.103 s ) B. ( 0.016 s ) c. ( 0.002 s ) D. ( 0.324 s ) |
10 |

36 | State the observations made by Oerested on the basis of his experiments with current carrying conductor. |
10 |

37 | wire/is/are connected directly to the electric meter. A. line wire B. earth wire c. neutral wire D. all |
10 |

38 | Net magnetic field at the centre ofthe circle 0 due to a current carrying loop as shown in figure is ( left(boldsymbol{theta}<mathbf{1 8 0}^{circ}right) ) A. zero B. perpendicular to paper inwards C. perpendicular to paper outwards D. is perpendicular to paper inwards if ( theta leq 90^{circ} ) and perpendicular to paper outwards if ( 90^{0} leq theta<180^{circ} ) |
10 |

39 | The potential difference between points A and B of adjoining figure is : 0 A. ( 2 / 3 V ) B. ( 8 / 9 V ) c. ( 4 / 3 V ) D. ( 2 V ) |
10 |

40 | Calculate combined resistance. | 10 |

41 | What is an AC generator? Obtain an expression for the sinusoidal emf induced in the cell of ac generator, rotating with a uniform angular speed in a uniform magnetic field. |
10 |

42 | The relation between an ac voltage source and time in Sl units is ( V= ) ( 120 sin (100 pi t) cos (100 pi t) V ) The value of peak voltage and frequency will be respectively: A. ( 120 mathrm{V} ) and ( 100 mathrm{Hz} ) B. ( frac{120}{sqrt{2}} mathrm{V} ) and ( 100 mathrm{Hz} ) c. ( 60 mathrm{V} ) and ( 200 mathrm{Hz} ) D. ( 60 mathrm{V} ) and ( 100 mathrm{Hz} ) |
10 |

43 | A step-up transformer operates on a ( 230 mathrm{V} ) line and a load current of ( 2 mathrm{A} ). The ratio of primary and secondary windings is ( 1: 25 . ) Then the current in the primary is? A . 25 A B. 50 A c. 15 A D. 12.5 A |
10 |

44 | Which one of the following heater element is used in electric press A. Copper wire B. Nichrome wire c. Lead wire D. Iron wire |
10 |

45 | State one advantage of using a.c. over d.c. |
10 |

46 | Magnetic lines of force due to a long straight conductor carrying current are A. straight lines B. elliptical c. circular D. parabolic |
10 |

47 | Why is the series arrangement not used for domestic circuits? | 10 |

48 | How much current is drawn by the primary of a transformer connected to ( 220 V ) supply when it delivers power to a ( 110 V-550 W ) refrigerator? |
10 |

49 | Which of the following is not a chemical cell A. Simple voltaic cell B. Leclanche cell c. Daniel cell D. Solar cell |
10 |

50 | Household electrical appliances are joined using combination of resistors A. Parallel B. Alternating c. continuous D. Series |
10 |

51 | In a circular current-carrying conductor, the face of the coil towards the observer behaves like a south pole if the current flows A. In clockwise direction B. In anticlockwise direction C. In alternating clockwise and anticlockwise direction D. First in anticlockwise for some time then in clockwise direction |
10 |

52 | Switch is always connected to the wire. A . live B. neutral c. ground D. live and ground |
10 |

53 | Define Electromagnetism A. The study of attraction or repulsion between two magnets is called electromagnetism B. The study of electric effects due to magnetic interaction is called electromagnetism C. The study of magnetic effects produced due to electric current is called electromagnetism D. The study of magnetic effects produced due to electric charge is called electromagnetism |
10 |

54 | Why is parallel arrangement used in domestic wiring? A. For getting same potential difference across each electrical appliance. B. For getting different potential difference across each electrical appliance. C. For getting high potential difference across each electrical appliance. D. For getting low potential difference across each electrical appliance. |
10 |

55 | Two dissimilar bulbs are connected in series, which bulb will be brighter? A. low resistance bulb B. more resistance bulb c. high current pass bulb. D. low current pass bulb |
10 |

56 | In the given circuit diagram the ratio of potential difference across 3 ohm and 4 ohm resistance is ( frac{3}{4} . ) The unknown resistance ( boldsymbol{R} ) is:- A. 8.0 ohm B. 2.0 ohm ( c .4 .5 ) ohm D. 7.0 ohm |
10 |

57 | Which of the following is/are energy efficient products? This question has multiple correct options A. Tube lights B. Bulbs c. LEDs D. CFLS |
10 |

58 | A house is fitted with 4 lamps 60 w each, 2 fans rated 100 w each, an electric kettle rated 2KW. If the energy ( operatorname{costs} ) Rs. 5.50 per ( mathrm{KWh} ), calculate the monthly bill (of 30 days) for running the appliances for 5 hours a day. |
10 |

59 | An electric bulb works on the principle of A. Archimedes B. heating effect of current c. magnetic effect of current D. none of these |
10 |

60 | The consumption of electrical energy in the house is measured in terms of: A. Kilowatt hour B. Watt hour c. Joules D. Kilo joules |
10 |

61 | An ideal choke takes a current of ( 8 A ) when connected to an a.c source of 100 volt and 50 Hz. A pure resistance under the same conditions takes a current of 10A. If two are connected in series to an a.c. Supply of ( 150 mathrm{V} ) and ( 40 mathrm{Hz} ), then the current in the series combination of above resistor and conductor is: |
10 |

62 | In the following diagram, the potentials is ( P ) and ( Q ) are A ( .40 V,-60 V ) в. ( 60 V,-40 V ) ( mathbf{c} cdot 40 V, 60 V ) D. ( 60 V, 40 V ) |
10 |

63 | At what voltage and frequency is the electric power generated at the power generating station? ( mathbf{A} cdot 15 k V, 50 H z ) в. ( 11 k V, 100 H z ) c. ( 11 k V, 50 H z ) D. ( 11 k V, 500 H z ) |
10 |

64 | Potential difference of ( 220-250 mathrm{V} ) is present between A. Earth wire and neutral wire B. Live wire and earth wire c. Live wire and neutral wire D. B and c both |
10 |

65 | ( ln ) an ( A C ) circuit, the instantanceous emf and current are given by ( e=100 sin 30 t, i=sin left(30 t frac{pi}{4}right) ) In one cycle of ( A C, ) the average power consumed by the circuit and the wattles current are, respectively A. 50,0 B. 50,10 c. ( frac{1000}{sqrt{2}}, 10 ) D. ( frac{50}{sqrt{2}}, 0 ) |
10 |

66 | The supply voltage to room is 120 ( V ). The resistance of the lead wires is ( 6 Omega . ) A ( 60 W ) bulb is already switched on. What is the decrease of voltage across the bulb, when a ( 240 W ) heater is switched on in parallel to the bulb? A . zero в. 2.9 volt c. 13.3 volt D. 10.04 Volt |
10 |

67 | The essential requirements for a good heating element are A. High resistivity and low melting point B. High resistivity and high melting point C. Low resistivity and low melting point D. Low resistivity and high melting point |
10 |

68 | calculate the current through a ( 60 mathrm{W} ) lamp rated for ( 250 mathrm{V} ). if the line voltage falls to ( 200 mathrm{V} ), how is the power consumed by the bulbs affected? | 10 |

69 | The amount of heat produced in a wire depends on its material- A. Length B. Thickness c. Length and thickness D. None of these |
10 |

70 | In an ac circuit the instantaneous values of current and applied voltage are respectively ( i= ) ( 2(A m p) sin left(250 pi s^{-1}right) t ) and ( epsilon= ) ( (10 V) sin left[left(250 pi s^{-1}right) t+frac{pi}{3}right] . ) Find the power drawn from the source at ( t= ) ( frac{2}{3} m s ) |
10 |

71 | The most important safety method used for protecting home appliances from short circuiting or overloading is A. earthing. B. use of fuse c. use of stabilizers D. use of electric meter. |
10 |

72 | State whether true or false: The magnetic polarity of an electromagnet does not change with the change in the direction of current in its coil. A. True B. False |
10 |

73 | Strong magnetic field produced inside a solenoid can be used to magnetise a A. piece of magnetic material B. soft iron ( c . ) both D. none |
10 |

74 | Which of the following materials is best suited as the core of an electromagnet A. steel B. Iron c. Alnico D. Magnetite |
10 |

75 | The direction of current in the coil at one end of an electromagnet is clockwise. This end of the electromagnet is. A. north pole B. south pole c. east pole D. west pole |
10 |

76 | In the direct current A. The direction of current is always positive B. The direction of current is always negative C. The direction of current changes constantly D. The direction of current is always in the same direction. |
10 |

77 | Two lamps, one rates ( 100 mathrm{W} ; 220 mathrm{V} ), and the other ( 60 mathrm{W} ; 220 mathrm{V} ) are connected in parallel to electric mains supply. Find the current drawn by two bulbs from the line, if the supply voltage is ( 220 mathrm{V} ) |
10 |

78 | An air conditioner is rated ( 240 V, 1.5 k W . ) The air conditioner is switched on for 8 hours each day. How much electrical energy is consumed in 30 days? ( mathbf{A} cdot 360 k W h ) B. ( 8.64 mathrm{kW} ) h ( mathbf{c} cdot 120 k W h ) D. ( 240 mathrm{kW} ) h |
10 |

79 | The element of an electric heater is made of : A. Tin B. Copper c. Nichrome D. Tungsten |
10 |

80 | The outlets in your home provide. A. Direct current B. Alternating current C. Electric discharge D. Static Electricity |
10 |

81 | Choose the incorrect option: Expansion during heating: A. occurs only in a solid B. increases the density of the material c. decreases the density of the material D. occurs at the same rate for all liquids and gaseous |
10 |

82 | A bulb marked ( 12 V, 24 W ) operates 12 volt battery for 20 minutes. The current flowing through it is : A ( .2 A ) в. ( 0.5 A ) ( c cdot 1 A ) D. ( 1.5 A ) |
10 |

83 | The magnitude of a magnetic field at the centre of a circular coil of radius ( R ) having ( N ) turns and carrying a current can be doubled by changing ( mathbf{A} cdot I ) to ( 2 I ) and ( N ) keeping ( R ) unchanged B. ( N ) to ( frac{N}{2} ) and keeping ( I ) and ( R ) unchanged C . ( N ) to ( 2 N ) and ( R ) keeping ( 2 R ) keeping/unchanged D. ( R ) to ( 2 R ) and ( l ) to ( 2 I ) keeping ( N ) unchanged E . ( I ) to ( 2 I ) and keeping ( N ) and ( R ) unchanged |
10 |

84 | Electrical welding works on principle of: A. continuity equation of electric current B. heating effect of electric current C. heating effect of exothermic reactions D. none of the above |
10 |

85 | Write the equation of 25 cycle current sine wave having rms value of ( 30 A ) |
10 |

86 | Mark the incorrect statement. A. In our homes, we receive supply of electric power through a main supply B. Red insulation cover, is called live wire C. The earth wire, has insulation of green colour D. None |
10 |

87 | Statement 1: Electric current (flow of electrons) creates heat in the resistor. Statement 2: Heat in the resistor is created according to the rule of energy conservation. Explain Statement 1 with the help of Statement 2. |
10 |

88 | The kilowatt hour is the unit of | 10 |

89 | Mark the correct reason/s why nichrome is used for making heating element of electrical appliances. A. Nichrome does not oxidize B. Nichrome doesn’t burn easily at high temperatures as it has higher melting and boiling point than metals C. Nichrome has higher resisistivity and consequently a higher resistance D. All |
10 |

90 | Find the number of electrons transferred between two points kept at a potential difference of ( 20 mathrm{V}, ) if 401 of work is done Name the colorless transporting fluid found in humans |
10 |

91 | A light bulb is rated at ( 100 mathrm{W} ) for a ( 220 mathrm{V} ) supply. Find the peak voltage of the source. |
10 |

92 | Dry cell is a source of A. Direct current B. Alternating current C. Can be used as direct current source or alternating current source D. Cant say |
10 |

93 | A current is flowing in electricity line towards north, the direction of magnetic field at a point which is just below the line is : A. towards north B. towards south c. towards east D. towards west |
10 |

94 | Which statement is wrong from the following? A. The earthing wire is green coloured. B. In India, current flowing through wire is ( A C ) and its frequency is ( 50 mathrm{Hz} ) C. In India, voltage between two wires is ( 110 V ) D. T.V., Tublight, bulbs are connected with ( 5 A ) line. |
10 |

95 | How is an electromagnet different from a permanent magnet? | 10 |

96 | In case of A.C, circuit, Ohm’s law holds good for a) Peak values of voltage and current b) Effective values of voltage and current c) Instantaneous values of voltage and current A. only a is true B. only a and b are true c. only c is true D. a, b anc c are true |
10 |

97 | In a city, electricity costs ( $ 0.12 ) per kilowatt-hour. A bulb of 150-watt operates for 5 hours. Calculate the cost of electricity which is consumed by the bulb. A. ( $ 0.009 ) в. $0.09 c. ( $ 0.90 ) D. $9.00 E. ( $ 90.00 ) |
10 |

98 | The electric current passing through a metallic wire produces heating because of: A. collisions of conduction electrons with each other B. collisions of the atoms of the metal with each other c. the energy released in the ionisation of the atom of the metal D. collisions of the conduction electrons with the atoms of the metallic wire |
10 |

99 | At what voltage is the electric power from generating station transmitted? A ( .200 k V ) В. ( 11 k V ) ( mathbf{c} cdot 220 V ) D. ( 220 k V ) |
10 |

100 | Nidhi has two bulbs connected across two cells in a simple circuit as shown. How can she make the bulbs glow dimmer? A. Replace one cell with a piece of chalk. B. Replace one cell with a piece of wire. C. Replace one bulb with a piece of wire. D. Replace one bulb with another cell. |
10 |

101 | On which principle A.C generator works? |
10 |

102 | Mica is used in electrical appliances such as electric iron because mica is A. a good conductor of heat but a bad conductor of electricity B. a bad conductor of heat but a good conductor of electricity C. a good conductor of heat as well as electricity D. a bad conductor of heat as well as electricity |
10 |

103 | An electric heater consists of a nichrome coil and runs under ( 220 V ) consuming ( 1 k W ) power. Part of its coil burned out and it was reconnected after cutting off the burnt portion, The power it will consume now is: A. More than ( 1 k W ) B. Less that ( 1 k W ), but not zero ( mathrm{c} .1 mathrm{kW} ) D. ( 0 k W ) |
10 |

104 | Name any six domestic appliances based on the heating effect of electric current |
10 |

105 | A multimeter reads a voltage of a certain A.C. source as ( 100 mathrm{V} ). What is the peak value of voltage of A.C. source? A . 200 B. 100 V c. ( 141.4 mathrm{v} ) D. 400 |
10 |

106 | State whether given statement is True or False
An alternating current cannot be used for electroplating. |
10 |

107 | A current of ( 0.2 A ) flows through a wire whose ends are at a potential difference of ( 15 V . ) The heat energy produced in 1 minute will be ( mathbf{A} cdot 60 J ) в. ( 120 J ) ( c .180 J ) D. ( 90 J ) |
10 |

108 | The charge flowing through a resistance ( R ) varies with time ( t ) as ( Q=a t-b t^{2} ) where ( a ) and ( b ) are positive constants. Calculate the total heat produced in ( R ) |
10 |

109 | One metal wire is kept in east- west direction. ( I ) is the current flow due west. Then, due to magnetic field ( vec{B} ) of the earth on the wire is in the Direction. A. downward B. Upwarddardpwardd c. north D. south |
10 |

110 | Three resistors of values ( 2 Omega, 4 Omega, 6 Omega ) are connected is series. The equivalent resistance of combination of resistors is |
10 |

111 | The unit in which we pay the cost of electricity is A. kilowatt hour B. watt hour c. joules D. ergs |
10 |

112 | What is the frequency of A.C. in India? | 10 |

113 | Why are in the household electric circuits the electric appliances (instruments) connected in parallel combination? |
10 |

114 | Distinguish between the term overloading and short circuiting as used in domestic circuits |
10 |

115 | Which is or are the correct for filament of bulb? This question has multiple correct options A. Low melting point B. High melting point c. Made of tungsten D. Made of nichrome |
10 |

116 | An electric bulb is marked ( 200 vee, 100 W ) Calculate electrical resistance of its filament. If five such bulbs are connected in series to a ( 200 mathrm{V} ) supply, how much current will flow through them? |
10 |

117 | Three resistors are connected to a ( 6 mathrm{V} ) battery as shown in the figure given Calculate the potential difference across the ( 7.2 Omega ) resistor |
10 |

118 | A filament bulb ( 500 mathrm{W}, 100 mathrm{V} ) is to be used in a ( 230 mathrm{V} ) main supply. When a resistance ( R ) is connected in series, it works perfectly and the bulb consumes ( 500 mathrm{W} ). The value of ( mathrm{R} ) is :- A . ( 26 Omega ) B. 13Omega c. ( 236 Omega ) D. ( 46 Omega ) |
10 |

119 | An electrical device draws ( 2 mathrm{kW} ) power from ac mains voltage ( 223 mathrm{V}(mathrm{rms}) . ) The current differs lags in phase by ( phi= ) ( tan ^{-1}[]-frac{3}{4}[mathbb{1}] ) as compared to voltage. The resistance ( R ) in the circuit is A . ( 15 Omega ) в. 20 ( Omega ) ( c .25 Omega ) D. 30 ( Omega ) |
10 |

120 | A centre tapped transformer is rated 12 0-12 V. The peak voltage obtained is A . 12 v B. ( frac{12}{sqrt{2}} V ) ( mathrm{c} cdot 12 sqrt{2} V ) D. ( 24 V ) E ( .24 sqrt{2} V ) |
10 |

121 | A metal plate can be heated by A. passing either a direct or alternating current through the plate. B. placing in a time varying magnetic field. c. placing in a space varying magnetic field, but does not vary with time. D. both (a) and (b) are correct |
10 |

122 | The maximum current which can flow through a fuse without melting it is called its A. potential B. power c. rating D. capacity |
10 |

123 | A steady P.D. of ( 10 V ) produces heat at a rate of ( ^{prime} x^{prime} ) in a resistor. The peak value of A.C. voltage which will produce heat at the rate of ( x / 2 ) in the same resistor is: A . ( 5 V ) B. ( 5 sqrt{2} v ) ( c .10 V ) D. ( 10 sqrt{2} mathrm{v} ) |
10 |

124 | A lamp rated ( 100 W ) at ( 22 V ) is connected to the main electric supply. What current is drawn from the supply line if the voltage is ( 220 V ) |
10 |

125 | Name the device used to increase the voltage at the generating station. A. Transformer B. Capacitor c. Diodes D. None of the above |
10 |

126 | Voltmeter is an instrument used to measure A . Electric current B. Electric charge c. Resistance D. Potential difference |
10 |

127 | Which part of the bulb is an insulator? ( A ) B. ( c cdot R ) D. |
10 |

128 | State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery? |
10 |

129 | A filament bulb ( (500 W, 100 V) ) is to be used in a ( 230 mathrm{V} ) main supply. When a resistance ( R ) is connected in series, it works perfectly and the bulb consumes ( mathbf{5 0 0} boldsymbol{W} ). The value of ( boldsymbol{R} ) is. A . ( 13 Omega ) B . ( 230 Omega ) c. ( 46 Omega ) D. 26 Omega |
10 |

130 | Two bulbs, one of ( 200 W ) and the other of ( 100 W, ) are connected in series with a ( 100 V ) battery which has no internal resistance. Then, A. The current passing through the ( 200 W ) bulb is more than that through the ( 100 mathrm{W} ) bulb B. The power dissipation in the ( 200 W ) bulb is less than that In the ( 100 mathrm{W} ) bulb c. The voltage drop across the ( 200 W ) bulb is more than that across the ( 100 mathrm{W} ) bulb D. The power dissipation In the ( 100 W ) bulb is more than that in the ( 200 mathrm{W} ) bulb |
10 |

131 | The wire having a black plastic covering is a A. live wire B. neutral wire c. earth wire D. none of these |
10 |

132 | All power entering a house enters via A. Electricity Meter B. Various loads in house C. Electricity board motor D. Potential Barrier |
10 |

133 | Name two special characteristics of a heater coil. |
10 |

134 | The electrical appliances in a house are connected in : A. series B. parallel c. either in series or parallel D. both in series and parallel |
10 |

135 | Two identical parallel plate capacitors are connected in series and then joined with a battery of ( 100 ~ V . A ) sheet of dielectric constant 4.0 is inserted between the plates of second capacitor. The potential difference across the capacitors will be respectively. ( mathbf{A} cdot 50 V, 50 V ) B . ( 80 mathrm{V}, 20 mathrm{V} ) c. ( 20 V, 80 V ) D. ( 75 V, 25 V ) |
10 |

136 | An electric oven of ( 2 mathrm{kW} ) power rating is operated in a domestic electric circuit that has a current rating of 5A. If the supply voltage is ( 220 mathrm{V} ), what result do you expect? A . circuit will be breaked B. fuse will blow ( c . ) both D. none |
10 |

137 | If four resistances, each of value 1 ohm, are connected in series, what will be the resultant resistance? ( A . ) 3 ohm B. 4 ohm c. 5 ohm D. 2 ohm |
10 |

138 | A resistance of ( 20 Omega ) is connected to a source of an alternating potential ( boldsymbol{V}= ) ( 220 sin (100 pi t) . ) The time taken by the current to change from the peak value to rms value, is A . ( 0.2 s ) B. ( 0.25 s ) c. ( 2.5 times 10^{-2} s ) D. ( 2.5 times 10^{-3} s ) |
10 |

139 | A washing machine rated ( 300 W ) is operated for one hour/day. If the cost of a unit is Rs 3.00 then the cost of the energy to operate a washing machine for the month of March is A ( . ) Rs 25.60 B . ( R s 27.50 ) c. ( R s 27.90 ) D. ( R s 26.90 ) |
10 |

140 | If the current is flowing through a ( 10 Omega ) resistor, then in which case the maximum heat will be generated? A. 5 ampere in 2 minutes B. 4 ampere in 3 minutes c. 3 ampere in 6 minutes D. 2 ampere in 5 minutes |
10 |

141 | Two bulbs of ( 100 mathrm{W} ) and ( 40 mathrm{W} ) are connected in series. The current through the 100 W bulb is 1A. The current through the 40 W bulb will be A ( .0 .4 A ) в. ( 0.6 A ) ( c .0 .8 A ) D. ( 1 A ) |
10 |

142 | Which of the following is a source of direct current. A . Cell B. Electromagnet c. Bulb D. Switch |
10 |

143 | A moving charge produces A. Neither electric field nor magnetic field B. Electro-static field only C. Magnetic field only D. Both magnetic and electro-static field |
10 |

144 | The frequency of A.C mains in India is A. ( 30 c / s ) B. ( 50 c / s ) ( mathbf{c} cdot 60 c / s ) D. ( 120 c / s ) |
10 |

145 | Why are wires coated with plastic coverings: ( A ). to make it a bit decorative B. to make it more durable C. it order to make them distinguishable D. to make it shock free |
10 |

146 | State whether given statement is True or False
The designation rms means repetitions measured per second. |
10 |

147 | Name the colour used in insulated wired of electrical appliance. A. Blue B. Green c. Brown D. All of these |
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148 | Electromagnets are made of soft iron, because soft iron has A. High susceptibility and low retentivity B. Low susceptibility and high retentivity c. Low susceptibility and low retentivityy D. High susceptibility and high retentivity |
10 |

149 | What is the function of distribution box in domestic electrical circuit A. It distributes voltage across appliances as per need B. It provides isolation between set of appliances and improves reliability C. It distributes Losses among all parts of circuit equally D. It allows user to manually distribute power as per his need |
10 |

150 | A current carrying circular loop of radius R is placed in the ( x ) -y plane with centre at the origin. Half of the loop with ( x>0 ) is now bent so that it now lies in the ( y-z ) plane. A. The magnitude of magnetic moment now diminishes B. The magnetic moment does not change. C. The magnitude of ( bar{B} ) at ( (0,0, z), z>>R ) increases D. The magnitude of ( bar{B} ) at ( (0,0, z), z>>R ) is unchanged. |
10 |

151 | The frequency of A.C. (alternating current) provided to a household in USA is |
10 |

152 | State whether true or false. In a series circuit, all appliances work independently. A. True B. False |
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153 | Choose the incorrect statement. A. Alternating current is oscillatory B. Electric power is transmitted over long distances using alternating current C. Frequency of alternating current in India is ( 50 mathrm{Hz} ) D. Alternating current can be used for electrolysis of copper chloride. |
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154 | What will be the magnetic field at a distance r when an electric current flows through these things? Wire single turn of wire Several turn of wire |
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155 | Assertion An electric bulb becomes dim, when the electric heater in parallel circuit is switched on. Reason Dimness decreases after sometime. 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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156 | One complete set of negative and positive values of alternating quantities is called A. Time period B. Amplitude c. Frequency D. cycle |
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157 | An electric bulb generally uses a filament coated with A. Platinum B. Thorium c. silver D. Radium |
10 |

158 | The given graphs (a) and (b) represent the variation of the opposition offered by the circuit element to the flow of alternating current, with frequency of the applied emf.ldentify the circuit element corresponding to each graph |
10 |

159 | An electric bulb P rated ( 220 V, 60 W ) is working at full efficiency. Another identical bulb ( Q ) is connected across the mains as shown in the figure. The total power consumed is : A . ( 20 W ) в. ( 40 W ) ( c .30 W ) D. ( 70 W ) |
10 |

160 | Differentiate the following:( i=i_{0} e^{frac{-t}{R C}} ) | 10 |

161 | A certain network consists of two ideal and indentical voltage sources in series and a large number of ideal resistor. The power consumed in one of the resistor is ( 4 W ) when either of the two sources is active and other is replaced by a short circuit. The power consumed by same resistor when both sources are simultaneously active would be: A. 0 or ( 16 W ) B. ( 4 W ) or ( 8 W ) ( mathrm{c} .0 ) or ( 8 mathrm{W} ) D. ( 8 W ) or ( 16 W ) |
10 |

162 | If a soft iron is placed inside the current carrying coil, what is the name given to the device? | 10 |

163 | Why are the coils of electric toasters made of an alloy rather than a pure metal? |
10 |

164 | A current of 8 A flows through a 25 V car headlight bulb. Calculate the electric power (in Watts). |
10 |

165 | Write one merit and one de-merit of alternating current in comparison of direct current. Obtain expression for following in a pure inductive alternating current circuit i) Instantaneous value of current ii) Reactance of circuit iii) Peak value of current Draw curve for power in pure inductive circuit. |
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166 | Rate of dissipation of Joules heat in resistance per unit volume is (symbols have usual meaning) A ( . sigma E ) в. ( sigma J ) ( c . J E ) D. None |
10 |

167 | In a circular current-carrying conductor if the current is flowing in anticlockwise direction, then for an observer facing the coil, the coil behaves like a A. North pole B. South pole c. can be north or south pole D. Neither north nor south pole |
10 |

168 | The adjacent diagram shows a coil would around a soft iron bar XY. How can the strength of the electromagnet be increased? A. Increasing the current in the circuit B. Increasing the number of turns of the coil ( c . ) both ( a ) and ( b ) D. None of these |
10 |

169 | Which of the following graph indicates direct current? ( A ) B. ( mathbf{c} ) ( D ) |
10 |

170 | What are the characteristics of heating element used in electric heating device? |
10 |

171 | The various bulbs and other electrical appliances in a house are connected A. In a complicated manner B. In series c. In parallel D. Bulbs in series and others in parallel |
10 |

172 | Which of the following quantities is scalar? A. Dipole moment B. Electric force c. Electric field D. Electric potential |
10 |

173 | An electric fuse used in households works on which principle of A. Joule’s heating B. Coulomb’s law c. Maxwell’s law D. Ohm’s law |
10 |

174 | Fill in the blanks: The power circuit in the house uses ampere fuse. A. 5 B . 15 ( c .50 ) D. 220 |
10 |

175 | The peak voltage of 220 Volt ( A C ) mains (in Volt) is : A. 155.6 B. 220.0 ( c .31 ) D. 440.0 |
10 |

176 | Two heater coils 1 and 2 made of the same material are connected in parallel across the mains. The length and diameter of the wire of coil 2 are doubled of that coil ( 1 . ) Find the ratio of heat generated between coil land 2 A .1: 2 B. 1: 1 c. 2: 1 D. 3: 2 |
10 |

177 | A copper voltameter is connected in series with a coil of resistance ( 10 Omega ) When a steady current is passed through the circuit, ( 0.297 g ) of copper is found to be deposited at the cathode in 15 ( min ). The electrochemical equivalent of copper is ( 3.3 times 10^{-7} k g C^{-} . ) Heat liberated in the coil is: A. ( 900 J ) в. ( 90 J ) c. ( 9 J ) D. ( 9 k J ) |
10 |

178 | Shivam went for buying a CFL from Dmart, what safety mark he should look for? A. Agmark B. ISI mark c. Trade mark D. Brand logo |
10 |

179 | Which of the following equipment does not work on principle of Joule’s law? A . Electric Heater B. Electric Iron c. Electric Bulb D. Electric Fan |
10 |

180 | In a dry cell A. Chemical energy is converted into heat B. Electrical energy is converted into electrical energy C . Chemical energy is converted into electrical energy D. Chemical energy is constant |
10 |

181 | ( ln ) an A.C. circuit in 1 second current reduces to zero value 120 times. Hence the frequency of A.c. current is ( mathrm{Hz} ) A . 50 в. 100 c. 60 D. 120 |
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182 | The potential difference between any two points is measured in: A. volts B. joules c. coulombs D. none of these |
10 |

183 | What is the role of switch in an electric circuit ? |
10 |

184 | (i) Two sets ( A ) and ( B ), of three bulbs each, are glowing in two separate rooms.When one of the bulbs in set A is fused, the other two bulbs also cease to glow. But in set ( mathrm{B} ), when one bulb fuses, the other two bulbs continue to glow. explain why this phenomenon occurs. (ii) Why do we prefer arrangements of Set B for house circuiting? |
10 |

185 | An electric bulb is rated ‘ ( 100 W, 250 V^{prime} ) How much current will the bulb draw if connected to a ( 250 V ) supply A . ( 0.6 A ) в. ( 2.5 A ) ( c .5 A ) D. ( 0.4 A ) |
10 |

186 | Which colour code is used for live wire? A. Red B. Black c. Green D. Yellow |
10 |

187 | A straight conductor carrying a current is split into identical semicircular turns of radius ( r ) as shown in the figure. The magnetic induction at the center ( C ) of the circular loop is: A ( cdot frac{mu_{0}}{4 r_{n}} ) в. ( frac{mu_{0} i}{8 r} ) c. ( frac{mu_{0}}{2 r} ) D. zero |
10 |

188 | Device which works on Joule’s law of heating A. Electric bulb B. Electric heater c. Electric iron D. All |
10 |

189 | In an AC circuit A. The average value of current is zero B. The average value of square of current is zero C . The average power dissipation is zero D. The rms current is ( sqrt{2} ) time of peak current |
10 |

190 | When a current flows through a conductor its temperature A. May increase or decrease B. Remains same c. Decreases D. Increases |
10 |

191 | The wire having a green plastic covering is a A. live wire. B. neutral wire c. earth wire. D. none of these |
10 |

192 | Calculate the electrical energy consumed when a current of 4.5 ampere flows through a resistance of 4 ohms for 30 minutes. |
10 |

193 | A long straight conductor, carrying a current ( I, ) is bent to form an almost complete circular loop of radius ( r ) on it. The magnetic field at the center of the loop: A. is directed into the paper B. is directed out of the paper C . has magnitude ( frac{mu_{0} I}{2 r}left(1-frac{1}{pi}right) ) D. has magnitude ( frac{mu_{0} I}{2 r}left(1+frac{1}{pi}right) ) |
10 |

194 | Using an A.C. voltmeter the potential difference in the electrical line in a house is read to be 234 volts. If the line frequency is known to be 50 cycles/second, the equation for the line voltage is A. ( V=165 sin (100 pi t) ) B. ( V=331 sin (100 pi t) ) c. ( V=220 sin (100 pi t) ) D. ( V=420 sin (100 pi t) ) |
10 |

195 | Show that the current leads the voltage by an angle ( frac{pi}{2} ) in an ac circuit containing a pure capacitor. | 10 |

196 | The wire having a green plastic covering is a: A. Live wire B. Neutral wire c. Earth wire D. None of these |
10 |

197 | The frequency of alternating current in India is A. 50 cylces/s B. 100 cylces/s c. 150 cylces/s D. 200 cylces/s |
10 |

198 | In the absence of any current a compass needle rests in which direction (with respect to the Earth)? A. South-north B. North-south c. East-west D. west-east |
10 |

199 | The potentials of two wires coming from electric poles to our houses are: A. 440 volt and ( 220 mathrm{v} ) B. OV and 110v c. ov and ( 220 v ) D. 300V and 500v |
10 |

200 | Fill in the blanks with suitable words The Sl unit of electromotive force is |
10 |

201 | The heating element in an electric iron is made up of : A. nichrome B. iron c. constantan D. tungsten |
10 |

202 | A metallic piece gets hot when surrounded by a coil carrying high frequency alternating current. Why ( ? ) |
10 |

203 | If the r.m.s. value of A.C. is ( l_{r m s} ) then peak value is – A ( cdot sqrt{2} l_{r m s} ) B ( cdot l_{r m s} / sqrt{2} ) ( mathrm{c} cdot 2 sqrt{2} l_{m s} ) D ( cdot 2 l_{m s} ) |
10 |

204 | The electricity tariff in a town is ( R s .3 .00 ) per unit. Calculate the cost of running an ( 80 W ) fan for ( 10 h ) a day for the month of June. A . ( R s .12 .00 ) в. ( R s .52 .00 ) c. ( R s .72 .00 ) D. Rs.92.00. |
10 |

205 | Why are coils of electric toasters and electric irons made of an alloy rather that an pure metal? |
10 |

206 | A domain in ferromagnetic iron in the form of cube is having ( 5 times 10^{10} ) atoms. If the side length of this domain is 1.5 ( mu m ) and each atom has a dipole moment of ( 8 times 10^{-24} mathrm{A} m^{2}, ) then magnetisation of domain is? A. ( 11.8 times 10^{5} mathrm{A} mathrm{m}^{-1} ) B. ( 1.18 times 10^{4} mathrm{A} mathrm{m}^{-1} ) c. ( 11.8 times 10^{4} mathrm{A} mathrm{m}^{-1} ) D. ( 1.18 times 10^{5} mathrm{A} mathrm{m}^{-1} ) |
10 |

207 | A direct current of ( 5 A ) is superimposed on an alternating current ( boldsymbol{I}=mathbf{1 0} sin boldsymbol{omega} boldsymbol{t} ) flowing through a wire. The effective value of the resulting current will be ( mathbf{A} cdot(15 / 2) A ) B. ( 5 sqrt{3} A ) c. ( 5 sqrt{5} ) A D. 15 A |
10 |

208 | Complete the given statement. The voltage across each light bulb in a parallel circuit: A. is equal to the voltage of the battery B. is determined by the resistance of the bulb C. is determined by the current flowing through the bulb D. is equal to the sum of the voltages lost in each bulb E. is equal to the total current divided by the resistance of the bulb |
10 |

209 | Name the effect of current responsible for the glow of the bulb in an electric circuit. A. Chemical B. Heating c. Magnetic |
10 |

210 | An electric heater which is connected to a ( 220 mathrm{V} ) supply line has two resistance coils. ( A ) and ( B ) of ( 24 Omega ) resistance each. these coils can be used separately (one at a time), in series or in parallel. calculate the current drawn when: Only one coil A is used coils ( A ) and ( B ) are used in series |
10 |

211 | A heater at ( 220 V ) boils a volume of water in 5 minutes time. If the heater is operated at ( 110 V ), the same volume of water will boil in ( 10 n ) minutes. Find the value of ( n ? ) |
10 |

212 | Name the colour code of the wire which is connected to the metallic body of an appliance. |
10 |

213 | Find the resistance of ( 1000 mathrm{W}-250 mathrm{V} ) heater wire. |
10 |

214 | Which is not a correct advantage of parallel combination in domestic circuit? A. Same voltage of the mains is available for all electrical appliances. B. Switching on or off of one switch has no effect on the other C. If one appliance stops working, other appliances keep on working D. none |
10 |

215 | The diagram represents a magnetic field. What causes this field? ( A . ) A bar magnet B. A solenoid carrying a current C. A straight wire carrying a current D. Two north poles close together |
10 |

216 | Why are multiple fuses used in domestic electric circuit A. It reduces the average cost B. It increases efficiency of system C. It guarantees system will always work perfectly D. Failure of one of the fuses allow system to continue working in applications where fault has not ocured |
10 |

217 | The Magnetic effect of current was discovered by: A. John Ambrose Fleming B. Hans Christian Oersted c. Michael Faraday D. André-Marie Ampère |
10 |

218 | What happens to the reading of ( A_{1}, A_{2}, A_{3} ) and ( A ) when the bulb ( B_{2} ) gets fused? A ( . A_{1}=1 A, A_{2}=0 A, A_{3}=0 A ) and ( A=2 A ) B. ( A_{1}=1 A, A_{2}=0 A, A_{3}=1 A ) and ( A=2 A ) C. ( A_{1}=2 A, A_{2}=0 A, A_{3}=1 A ) and ( A=2 A ) D. ( A_{1}=1 A, A_{2}=0 A, A_{3}=1 A ) and ( A=1 A ) |
10 |

219 | Each electrical appliance is provided with a Fill in the blank. ( A cdot 3 ) B. 2 ( c ) D. 4 |
10 |

220 | For making an electromagnet the best material to be used is A. stainless steel B. silver c. soft iron D. nickel |
10 |

221 | What do you understand by the thermal effect of electric current? |
10 |

222 | Which of the following entities are closely associated to each other A. Gravitation and nuclear fusion B. Electricity and magnetism c. Chemical Bonding and Planetary motion D. None |
10 |

223 | Which of the following phenomenon can be related to electric current A. Magentism B. Gravitation c. Nuclear Fission D. chemical Bonding |
10 |

224 | The rating of a fuse depends upon the A. thickness of the fuse wire B. length of the wire ( c cdot ) both D. none |
10 |

225 | When does overloading occur? A. When live wire and neutral wire come into direct contact B. When live wire and neutral wire come into indirect contact C. When two live wires come into direct contact. D. When two neutral wire come into direct contact. |
10 |

226 | Derive an expression for the energy seated in a capacitor. In what form is the energy stored in a charged capacitor? |
10 |

227 | How the small bulbs, which are used for decoration purpose,are connected? A. in parallel B. in series c. in mixed order D. all of the above |
10 |

228 | Create a concept map using the following words.
Electromagnetism, Electricity, Magnetism, Solenoid, Electromagnet, Magnet field, Electromagnetic induction, Generators, and |
10 |

229 | An electric heater kept in vacuum is heated continuously by passing electric current. Its temperature: A. will go on rising with time B. will stop after sometime as it will loose heat to the surroundings by conduction C. will rise for sometime and thereafter will starts falling D. will become constant after sometime because of loss of heat due to radiation |
10 |

230 | An ac voltmeter reads ( 220 mathrm{V} ). If the line frequency is ( 50 H z, ) then the equation for the line voltage is A. ( V=220 sin 50 t ) B. ( V=220 sin 100 t ) c. ( V=311 sin 50 pi t ) D. ( V=311 sin 100 pi t ) |
10 |

231 | From below which are the applications of heating effect of electric current? A. Electric immersion water heater B. Electric Iron Box c. Electric Fuse D. All of the above |
10 |

232 | The frequency of A.C mains in India is ( mathbf{A} cdot 30 H z ) B. ( 50 H z ) ( mathbf{c} cdot 60 H z ) D. ( 120 H z ) |
10 |

233 | Horse shoe magnet is A. v shaped B. P shaped c. u shaped D. All |
10 |

234 | The colour code of a resistor is brown, black and brown. Then the value of resistance is A. ( 10 Omega ) в. 100 тл c. ( 0.1 k Omega ) D. 1000 ( Omega ) |
10 |

235 | If the length of the filament of a heater is reduced by ( 10 % ), the power of the heater will A. increase by about 9% B. increase by about 11% c. increase by about ( 19 % ) D. decrease by about ( 10 % ) |
10 |

236 | Assertion Sensitive electrical instruments should not be placed in the vicinity of an electromagnet. Reason Electromagnet can damage the instruments. 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 |
10 |

237 | The quantity ( boldsymbol{X}=frac{boldsymbol{epsilon}_{0} boldsymbol{L} boldsymbol{V}}{boldsymbol{t}}: boldsymbol{epsilon}_{0} ) is the permittivity of free space, ( boldsymbol{L} ) is length, ( boldsymbol{V} ) is potential difference and ( t ) is time. The dimensions of ( X ) are same as that of A . Resistance B. Charge c. voltage D. current |
10 |

238 | An electric meter reads 8950 KWh at the end of the month,while at the beginning of the month the reading was ( 8833 mathrm{KWh} ). How many units of electricity are consumed? If one unit ( operatorname{costs} ) Rs. ( 4.30, ) find the cost of the electrical energy consumed |
10 |

239 | An alternating voltage is represented as ( E=20 sin 300 t . ) The average value of voltage over one cycle will be? A. zero B. 10 volt c. ( 20 sqrt{2} ) volt D. ( frac{20}{sqrt{2}} ) volt |
10 |

240 | A.C power is transmitted from a power house at a high voltage as A. the rate of transmission is faster at high voltages B. it is more economical due to less power loss C. power cannot be transmitted at low voltages D. a precaution against theft of transmission lines |
10 |

241 | Fill the blank. Voltmeter is always connected in ( ldots ) with the device. A. series B. parallel c. series and parallel both D. the cell |
10 |

242 | ( ln operatorname{an} A C ) generator, a coil with ( N ) turns, all of the same area ( A ) and total resistance ( boldsymbol{R} ), rotates with frequency ( boldsymbol{omega} ) in a magnetic field ( B ). The maximum value of e.m.f. generated in the coil is : A. NABR ( omega ) B. NAB c. NABR D. NAB |
10 |

243 | A circular loop of radius R carries a current I. Obtain an expression for the magnetic field at a point on its axis at a distance ( x ) from its centre | 10 |

244 | A secondary cell can provide current. A . Low B. Highh c. Both D. None |
10 |

245 | A house has four tubelights, three fans and a television. Each tubelight draws ( 40 W . ) The fan draws ( 80 W ) and the television draws ( 100 mathrm{W} ). On an average, all the tubelights are kept on for 5 hours, all fans for 12 hours and the television for 6 hours everyday. Find the ( operatorname{cost} ) of electric energy used in 30 days at the rate of ( R s .3 .00 ) per KWH |
10 |

246 | Write two properties of magnetic field lines. |
10 |

247 | Generation of Alternating Current in India is done at ( A cdot 45 ) Н в. 50 нz c. 60 Н D. 55 Hz |
10 |

248 | The reading of the voltmeter connected across ( 20 Omega ) resistance is ( A cdot 15 V ) В. ( 10 V ) ( c .5 V ) D. ( 22.5 V ) |
10 |

249 | n the circuit shown, what is the potential difference ( V_{P Q} ? ) ( A cdot+3 V ) B. ( +2 v ) c. ( -2 v ) D. None of thes |
10 |

250 | An alternating current in circuit is ( operatorname{given} ) by ( I=20 sin (100 pi t+0.005 pi) A ) The r.m.s value and the frequency of current respectively are: A . ( 10 A ) and ( 100 H z ) B. ( 10 A ) and ( 50 mathrm{Hz} ) c. ( 10 sqrt{2} ) A and ( 50 mathrm{Hz} ) D. ( 10 sqrt{2} ) A and ( 100 mathrm{Hz} ) |
10 |

251 | Why are alloys commonly used in electrical heating devices? A. Due to high resistivity B. Due to low resistivity c. Due to high elasticity D. Due to medium resistivity |
10 |

252 | In the network shown, the sources of emf ( 2 vee, 12 ) V and 16 V are taken to be ideal. Select incorrect statements from the following: This question has multiple correct options A ( cdot ) The potential drop across ( 4 Omega ) is ( frac{28}{13} vee ) B. The current through 2 v battery is ( frac{17}{13} ) A, discharging. C ‘ the current through 2 V battery is ( frac{17}{13} ) A, charging. D. The potential drop across ( 8 Omega ) is ( frac{60}{13} vee ) |
10 |

253 | What will be the frequency of an alternating current, if its direction changes after every 0.05 s? A. ( 5 mathrm{Hz} ) в. 10нz ( c cdot 50 H z ) D. онz |
10 |

254 | The work that has to be done in transferring unit positive charge from one point to the other is called A. electric potential energy B. electrical potential c. electric potential difference D. electric field |
10 |

255 | The north-south polarities of an electromagnet can be determined with the help of A. Maxwell’s corkscrew rule B. right hand thumb rule c. clock face rule D. Fleming’s left-hand rule |
10 |

256 | Which of the following is FALSE ? A. some of the energy produced by the light bulb takes the form of heat B. the battery is the source of the electrons flowing around the circuit C. the current entering the light bulb equals the current leaving the light bulb D. the potential in the wire to the left of the light bulb differs from the potential in the wire to the right of the bulb |
10 |

257 | In our houses, we receive AC current at a voltage of with a frequency of |
10 |

258 | In which circuit can the lamps be switched on and off independently? ( A ) B. ( c ) ( D ) |
10 |

259 | An ( A C ) source is rated ( 220 V, 50 H z ) The average voltage, is calculated in a time interval of 0.01 s. It A. must be zero B. may be zero ( c . ) is never zero D. is ( (220 / sqrt{2}) V ) |
10 |

260 | What happens on connecting too many appliances at a time to a single socket? | 10 |

261 | If the instantaneous emf and the instantaneous current equations of an A.C. circuit are respectively ( e=E_{0} sin (omega t-pi / 6), i=I_{0} sin (omega t+ ) ( boldsymbol{pi} / boldsymbol{6}), ) then the phase difference between voltage and current is : A ( cdot frac{pi}{3} ) B. zero ( c cdot frac{pi}{2} ) D. |
10 |

262 | A temporary magnet is made of A. cast iron B. steel C. soft iron D. stainless steel |
10 |

263 | All domestic electrical circuits are connected A. In series B. In parallel c. Both D. None of these |
10 |

264 | Two capacitors of caacity ( C_{1} ) and ( C_{2} ) are connected in series and potential difference V is applied across it. Then the potential difference across ( C_{1} ) will be ( ^{mathrm{A}} cdot frac{C_{2} V}{C_{1}+C_{2}} ) в. ( frac{C_{1} V}{C_{1}+C_{2}} ) ( ^{c} cdotleft(1+frac{C_{2}}{C_{1}}right) V ) D. ( left(1-frac{C_{2}}{C_{1}}right) v ) |
10 |

265 | Two electric wires coming out of the meter are connected to the A. electric equipment B. switch of the bulbs c. main switch D. switch of the electric equipments |
10 |

266 | What two precautions should be taken to avoid the overloading of domestic electric circuits? |
10 |

267 | Every electric appliance is marked with This question has multiple correct options A. power B. potential difference c. charge D. resistance |
10 |

268 | Match the columns begin{tabular}{ll|l|l} & A & B \ a. & green plastic covering & 1. & live wire \ hline b. & black plastic covering & 2. & neutral wire \ c. & red plastic covering & 3. & earth wire end{tabular} A. a-2, b-3, c-1 B. ( a-1, b-2, c-3 ) c. ( a-3, b-1, c-2 ) D. ( a-3, b-2, c-1 ) |
10 |

269 | In domestic electric circuit,appliances are connected in parallel. Why? A. because it consumes less power B. because if one appliance stops working,other appliances keep on working c. because it is longer than series supply so can be distributed to the whole house D. it is comparatively easier to create. |
10 |

270 | The relationship between A.C voltage and time in Sl unit is ( V= ) ( 120 sin (100 pi T) cos (100 pi t) ) volt value of peak voltage and frequency will be : A. 120 volt and 100 ( mathrm{Hz} ) B . ( frac{120}{sqrt{2}} ) volt and ( 100 mathrm{Hz} ) c. 60 volt and 200 Hz D. 60 volt and 100 нz |
10 |

271 | A long, straight wire of radius a carries a current distributed uniformlt over its cross-section. The ratio of the magnetic fields due to the wire at distance ( frac{a}{3} ) and ( 2 a, ) respectively from the axis of the wire is? A ( cdot 2 / 3 ) B. ( 3 / 2 ) c. ( 1 / 2 ) D. 2 |
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272 | in figure carrying current ( boldsymbol{I} . boldsymbol{A} boldsymbol{B} ) and ( boldsymbol{B} boldsymbol{C} ) parts are straight, long, and at right angle. At ( D ) wire forms a circular turn DM ( N D ) of radius ( R . A B, B C ) parts are tangential to circular turn at ( N ) and ( D ) The magnetic field at the centre of circle is A ( cdot frac{mu_{0} I}{2 pi R}left(pi-frac{1}{sqrt{2}}right) ) B. ( frac{mu_{0} I}{2 R} ) c. ( frac{mu_{0} I}{2 pi R}left(pi+frac{1}{sqrt{2}}right) ) ( ^{mathrm{D}} cdot frac{mu_{0} I}{2 pi R}(pi+1) ) |
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273 | What are the characteristic properties of fuse wire? | 10 |

274 | Whenever an electric current is passed through a conductor,it gets heated up.this means that a part of electrical energy, given to the conductor, gets converted to A. potential energy B. gravitational energy c. heat energy D. none of these |
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275 | A current ( I ) is flowing in a straight conductor wire of length ( L ). The magnetic induction at a point perpendicular distance ( frac{L}{4} ) from its centre will be: A ( cdot frac{4 mu_{0} i}{sqrt{5} pi L} ) в. ( frac{mu_{0} i}{2 pi L} ) c. ( frac{mu_{0} i}{sqrt{2} L} ) D. zero |
10 |

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