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

#### List of wave optics Questions

Question No | Questions | Class |
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1 | When the light is incident at the polarizing angle on transparent medium, then the completely polarized light is A. refracted light B. reflected light c. refracted and reflected light D. neither reflected nor refracted light |
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2 | The light beams of intensities in the ratio of 9: 1 are allowed to interfere. What will be the ratio of the intensities of maxima and minima? A . 3: 1 B. 4: 1 c. 25: 9 D. 81: 1 |
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3 | With a monochromatic light, the fringe- width obtained in a Young’s double slit experiment is ( 0.133 mathrm{cm} . ) The whole setup is immersed in water of refractive index 1.33 , then the new fringe-width is A. ( 0.133 mathrm{cm} ) B. 0.1 ( mathrm{cm} ) c. ( 1.33 times 1.33 mathrm{cm} ) D. ( frac{1.33}{2} mathrm{cm} ) |
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4 | Two waves are said to have destructive interference if A. their frequencies are same B. their frequencies are doubled c. the phase difference is same D. the phase difference is ( 180^{circ} ) |
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5 | 011 28. In Young’s double-slit experiment, the separation between two coherent sources S, and S, is d and the distance between the source and screen is D. In the interference pattern, it is found that exactly in front of one slit, there occurs a minimum. Then the possible wavelengths used in the experiment are d d d² d d d (a) 2 =- ” D’3D’ 5D m d d d² (c) 2 = nsnin (d) 2 = 30 D’U (b) 2 = 50’9D 11. |
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6 | Two sound speakers are driven in phase by an audio amplifier at frequency ( 600 H z . ) The speed of sound is ( 340 m / s ) The speakers are on the ( y ) -axis, one at ( boldsymbol{y}=+1.0 boldsymbol{m} ) and the other at ( boldsymbol{y}= ) ( -1.0 m . ) A listener begins at ( y=0 ) and walks along a line parallel to the ( y ) -axis at a very large distance ( x ) away. At ( frac{theta}{2} ) angle she will first hear a maximum ( left(operatorname{after} 0^{circ}right) ) sound intensity. Find ( theta: ) |
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7 | 5. The wavefront of a light beam is given by the equation x + 2y + 3x = c (where c is arbitrary constant), then the angle made by the direction of light with the y-axis is (a) cos’ T (b) sin (c) cos vía (d) sint ha |
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8 | The phase change in reflected wave, when light wave suffers reflection at the interface from air to glass is A . в. ( frac{pi}{2} ) ( c . pi ) D. ( 2 pi ) |
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9 | Huygens principle of secondary waves A. allow us to find the focal length of a thick convex lens. B. give us the magnifying power of the microscope. C. is a geometrical method to find, the position of a wave front D. is used to determine the velocity of light. |
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10 | Two circularly shaped linear polarisers are placed coaxially. The transmission axis of the first polarizer is at ( 30^{circ} ) from the vertical while the second one is at ( 60^{circ}, ) both in the clockwise sense. If an unpolarised beam of light of intensity ( I=20 W / m^{2} ) is incident on this pair of polarisers, then the intensities ( I_{1} ) and ( I_{2} ) transmitted by the first and the second polarisers, respectively, will be close to. A ( cdot I_{1}=10.0 W / m^{2} ) and ( I_{2}=7.5 W / m^{2} ) B . ( I_{1}=20 W / m^{2} ) and ( I_{2}=15 W / m^{2} ) C ( . I_{1}=10.0 W / m^{2} ) and ( I_{2}=8.6 W / m^{2} ) D. ( I_{1}=15.0 W / m^{2} ) and ( I_{2}=0.0 W / m^{2} ) |
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11 | 14. The speed of light in the medium is (a) minimum on the axis of the beam (b) the same everywhere in the beam (c) directly proportional to the intensity I (d) maximum on the axis of the beam |
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12 | he slits are 2 mm mum distance from 2 m from the 5. In a Young’s double slit experiment, the slits are apart and are illuminated with a mixture of two wavele 20 = 750 nm and 2 = 900 nm. The minimum distan the common central bright fringe on a screen 2 m fron slits where a bright fringe from one interference pa coincides with a bright fringe from the other is (a) 1.5 mm (b) 3 mm (c) 4.5 mm (d) 6 mm data tee |
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13 | What do you mean by coherent source. | 12 |

14 | The wavefront of a lightbeam is given by the equation ( x+2 y+3 z=c, ) (where ( c ) is arbitary constant) the angle made by the direction of light with the y-axis is: A ( cdot cos ^{-1} frac{1}{sqrt{14}} ) B. ( cos ^{-1} frac{2}{sqrt{14}} ) c. ( sin ^{-1} frac{1}{sqrt{14}} ) D. ( sin ^{-1} frac{2}{sqrt{14}} ) |
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15 | For which colour is the fringe width minimum? A . violet B. red c. green D. yellow |
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16 | 70. Calculate the wavelength of light used in an interference experiment from the following data: Fringe width = 0.03 cm. Distance between slits and eyepiece through which the interference pattern is observed is 1 m. Distance between the images of the virtual source when a convex lens of focal length 16 cm is used at a distance of 80 cm from the eyepiece is 0.8 cm (a) 6000 Å (b) 0,00006 Å (c) 6000 cm (d) 0.00006 m |
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17 | The angle between polariser and analyser is ( 30^{circ} ) The ratio of intensity of incident light and transmitted by the analyser is A. 3: 4 B. 4: 3 c. ( sqrt{3}: 2 ) D. ( 2: sqrt{3} ) |
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18 | For constructive interference, the path difference between two waves must be A ( cdot(2 n+1) lambda / 2 ) B. ( (2 n+1) lambda ) c. ( _{n frac{lambda}{2}} ) D. ( n lambda ) |
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19 | The tip of a needle does not give a sharp image on a screen. This is due to A. Polarisation B. Interference c. Diffraction D. None of these |
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20 | A person wants to see two pillars from a distance of ( 11 mathrm{km}, ) separately. The distance between the pillars must be approximately A. 3.2m B. ( 1 mathrm{m} ) c. ( 0.25 mathrm{m} ) D. 0.5 ( m ) |
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21 | In YDSE of equal width slits, if intensity at the centre of screen is ( I_{0}, ) then intensity at a distance of ( beta / 4 ) from the central maxima is ( (beta ) is the fringe width) : A ( cdot I_{0} ) в. ( frac{I_{0}}{2} ) c. ( frac{I_{0}}{4} ) D. ( frac{I_{0}}{3} ) |
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22 | 12. As the beam enters the medium, it will (a) diverge (b) converge (c) diverge near the axis and converge near the periphery (d) travel as a cylindrical beam |
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23 | The interfering fringes formed by a thin oil film on water are seen in yellow light of sodium lamp. We find the fringes A . coloured B. black and white c. yellow and black D. coloured white yellow |
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24 | ( S_{1}, S_{2} ) are two coherent sources (having initial phase difference zero) of sound located along ( x- ) axis separated by ( 4 lambda ) where ( lambda ) is wavelength of sound emitted by them. Number of maxima located on the elliptical boundary around it will be : A . 16 B. 12 ( c ) ( D .4 ) |
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25 | What will be the wavelength of the ( x ) rays which give a diffraction angle ( 2 theta ) equal to ( 16.80^{circ} ) for a crystal, if the inter planner distance in the crystal is 0.200 nm and only first order diffraction is observed ( left(sin 8.40^{circ}=0.146right) ) |
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26 | Q Type your question mass-less thread in vertical plane. When a beam of light of intenisty ( 1 W m^{-2} ) is made an incident normally on the mirror, it gets displaced so that the thread makes angle ( theta ) with the vertical. Assuming the mirror is perfectly reflecting, the value of ( boldsymbol{theta} ) (Consider it very small) is ( ^{A} cdot frac{2 I m}{c a q} ) в. ( frac{2 I c}{m a} ) c. ( frac{2 I g}{c a m} ) D. ( frac{2 I a}{c m q} ) |
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27 | Unpolarised light is incident from air on a plane surface of a material of refractive index’ ( mu^{prime} . ) At a particular angle of incidence ( ^{prime} boldsymbol{i}^{prime}, ) it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation? A ( cdot i=sin ^{-1}left(frac{1}{mu}right) ) B. Reflected light is polarised with its electric vector parallel to the plane of incidence C. Reflected light is polarised with its electric vector perpendicular to the plane of incidence D. ( i=tan ^{-1}left(frac{1}{mu}right) ) |
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28 | The YDSE apparatus is as shown in the figure. The condition for point ( boldsymbol{P} ) to be a dark fringe is ( (l= ) wavelength of light waves) A ( cdotleft(l_{1}-l_{3}right)+left(l_{2}-l_{4}right)=n lambda ) ( left(l_{1}-l_{2}right)+left(l_{3}-l_{4}right)=frac{(2 n+1) lambda}{2} ) c. ( left(l_{1}+l_{3}right)+left(l_{2}+l_{4}right)=frac{(2 n-1) lambda}{2} ) ( left(l_{1}-l_{2}right)+left(l_{4}-l_{3}right)=frac{(2 n-1) lambda}{2} ) |
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29 | Assertion Thin films such as soap bubble or a thin layer of oil on water show beautiful colors when illuminated by white light. Reason It happens due to the interference of light reflected from the upper surface of thin film. |
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30 | Two sound speakers are driven in phase by an audio amplifier at frequency ( 600 H z . ) The speed of sound is ( 340 m / s ) The speakers are on the ( y ) -axis, one at ( boldsymbol{y}=+mathbf{1 . 0 m} ) and the other at ( boldsymbol{y}= ) ( -1.0 m . ) A listener begins at ( y=0 ) and walks along a line parallel to the ( y ) -axis at a very large distance ( x ) away. How many maxima can she possibly hear if she keeps walking in the same direction? |
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31 | Young’s double slit experiment is performed at 589 nm light with a distance of ( 2.00 mathrm{m} ) between the slits and the screen. The tenth interference minimum is observed 7.26 ( mathrm{mm} ) from the central maximum. The spacing of the slits is A. ( 15.4 m m ) B. ( 154 m m ) c. ( 1.54 m m ) D. ( 0.154 mathrm{mm} ) |
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32 | 33. A double-slit arrangement produces interference fringes for sodium light (a = 589 nm) that have an angular separation of 3.50 x 0-rad. For what wavelength would the angular separation be 10% greater? (a) 527 nm (b) 648 nm (c) 722 nm (d) 449 nm |
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33 | BA pe 2. Figure shows that P and are two equally intense coherent sources emitting radiations of wavelength 20 m. The separation PQ is 5.0 m and phase of P is ahead of the phase of Q by 90°. A, B and C are three distant points of observation equidistant from the mid-point of PQ. The intensity of radiations at A, B, C will bear the ratio (a) 0:1:4 (b) 4:1:0 (c) 0:1:2 (d) 2:1:0 1. 000 and noth :ffavene |
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34 | In Young’s double-slit experiment, the separation between the slits is ( boldsymbol{d} ) distance between the slit and screen is ( D(D>>d) . ) In the interference pattern, there is a maxima exactly in front of each slit. Then the possible wavelength(s) used in the experiment are A ( cdot d^{2} / D, d^{2} / 2 D, d^{2} / 3 D ) B . ( d^{2} / D, d^{2} / 3 D, d^{2} / 5 D ) C . ( d^{2} / 2 D, d^{2} / 4 D, d^{2} / 6 D ) D. none of these |
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35 | Unpolarized light of intensity ( 32 W m^{-2} ) passes through three polarizes such that the transmission axis of the last polarizers is crossed with that of the first. The intensity of final emerging light is ( 3 W m^{-2} ). The intensity of light transmitted by the first polarizered will be ( mathbf{A} cdot 32 W m^{-2} ) B. ( 16 mathrm{Wm}^{-2} ) ( mathrm{c} cdot 8 mathrm{Wm}^{-2} ) D. ( 4 mathrm{Wm}^{-2} ) |
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36 | When a low flying aircraft passes over head, we sometimes notice a slight shaking of the picture on our TV screen Identify the optical phenomenon behind ¡t. |
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37 | Plane of polarisation is: This question has multiple correct options A. the plane in which vibrations of the electric vector takes place B. a plane perpendicular to the plane in which vibrations of the electric vector takes place C . perpendicular to the plane of vibration D. horizontal plane |
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38 | A water film having a refractive index of 1.33 in air is 320 nm thick. If it is illuminated with white light at normal incidence, the light of what wavelength (in ( mathrm{nm} ) ) will appear to be in reflected light? | 12 |

39 | If ( z=frac{lambda D}{2 d} ) ( A ) B. 1/2 ( c cdot 3 / 2 ) D. 2 |
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40 | 200 49. Out of the following statements which is not correct? (a) When unpolarised light passes through a Nicol’s prism, the emergent light is elliptically polarised (b) Nicol’s prism works on the principle of double refraction and total internal reflection (c) Nicol’s prism can be used to produce and analyse polarised light (d) Calcite and Quartz are both doubly refracting crystals |
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41 | A white light is passed through the two narrow slits and produced a pattern of alternating bright and dark lines on the screen as shown above. What will effects on the central bright band, if the distance between screen and slits are increased? A. become wider B. become narrower C. remain unchanged D. disappear completely E . rotate ( 90^{circ} ) |
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42 | Draw a neat labelled diagram of reflection of light from a plane reflecting surface on the basis of wave theory. | 12 |

43 | 25. In Young’s double-slit experiment, how many maximas can be obtained on a screen (including the central maximum) on both sides of the central fringe (a = 2000 Å)? (a) 12 (b) 7 (c) 18 (d) 4 |
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44 | White light reflected at normal incidence from a soap film has minima at ( 6500 A ) and maxima at ( 7500 A ) in the visible region with not minima in between. If ( mu ) is ( frac{5}{3} ) for the thin film, the thickness of film is : A ( cdot 7.40 times 10^{-7} mathrm{cm} ) B. ( 9.75 times 10^{-5} mathrm{mm} ) c. ( 9.70 times 10^{-7} mathrm{cm} ) D. ( 9.75 times 10^{-4} mathrm{mm} ) |
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45 | statement 1: In Young’s experiment, the fringe width for dark fingers is different from that for white fringes. statement 2: In Young’s double slit experiment the fringes are performed with a source of white light, then only black and bright fringes are observed. A. If both statement 1 and statement 2 are true but statement 2 is the correct explanation of statement B. If both statement 1 and statement 2 are true but statement 2 is not the correct explanation statemen c. If statement 1 is true but statement 2 is false D. If both the statement 1 and statement 2 are false E. If statement 2 is true but statement 1 is false |
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46 | Figure shows plane waves refracted from air to water using Huygen’s principle ( a, b, c, d, e ) are lengths on the diagram. Find the ratio of refractive index of water w.r.t. air. |
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47 | A beam of light consists of a bundle of light rays. A . True B. False |
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48 | sources of light of wavelength ( lambda ) are placed on the dotted line in front of a large screen. The source emit waves in phase with each other. The distance between ( S_{1} ) and ( S_{2} ) is ( ^{prime} d^{prime} ) while their distance from the screen is much larger. Then, (a) If ( d=7 lambda / 2, O ) will be minima (b) If ( d=4.3 lambda ), there will be total of 8 minima on y-axis (c) If ( d=7 lambda, O ) will be maxima. (d) If ( d=lambda ), there will be only one maxima on the screen. Which is the set of correct statement: A. ( a, b ) and ( c ) B. ( b, c ) and ( d ) c. ( a, b, c ) and ( d ) D. ( a, c ) and ( d ) |
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49 | A double slit is illuminated by light of wave length ( 6000 A^{0} ). The slits are ( 0.1 mathrm{cm} ) apart and the screen is placed 1 m away Then the angular position of 10 th maxima is A . ( 6 times 10^{-3} r a d ) B. 6 rad c. ( 0.006^{circ} ) D. ( 6^{circ} ) |
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50 | Can we perform Young’s double slit experiment with sound waves? To get a reasonable “fringe pattern”, what should be the order of separation between the slits? How can the bright fringes and the dark fringes be detected in this case? | 12 |

51 | When two progressive waves of intensity ( boldsymbol{I}_{1} ) and ( boldsymbol{I}_{2} ) but slightly different frequencies superpose, the resultant intensity fluctuates between ( mathbf{A} cdot(sqrt{I_{1}}+sqrt{I_{2}})^{2} ) and ( (sqrt{I_{1}}-sqrt{I_{2}})^{2} ) B ( cdot(sqrt{I_{1}}-sqrt{I_{2}}) ) and ( (sqrt{I_{1}}+sqrt{I_{2}}) ) ( mathbf{C} cdotleft(I_{1}+I_{2}right) ) and ( left(I_{1}-I_{2}right) ) D. ( left(I_{1}+I_{2}right)^{2} ) and ( left(I_{1}-I_{2}right)^{2} ) |
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52 | In Young’s double slit experiment the intensity of the maxima is ( I . ) If the width of each slit is doubled, the intensity of the maxima will be: ( mathbf{A} cdot I / 2 ) B. ( 2 I ) c. ( 4 I ) D. ( I ) |
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53 | A biprism is placed at a distance of 50 ( mathrm{mm} ) in front of a narrow slit illuminated by light of wavelength ( 600 mathrm{nm} ). The virtual images formed by the biprism are ( 0.5 mathrm{mm} ) apart. Find the width of the fringes formed on a screen placed 0.75 ( mathrm{m} ) apart in front of the biprism. A. ( 0.96 mathrm{cm} ) B. ( 0.096 mathrm{cm} ) c. ( 0.0096 mathrm{cm} ) D. 9.6 ( mathrm{cm} ) |
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54 | Two loud speakers ( L_{1} ) and ( L_{2}, ) driven by a common oscillator and amplifier, are arranged as shown. The frequency of the oscillator is gradually increased from zero and the detector at D records a series of maxima and minima. If the speed of sound is ( 330 mathrm{m} / mathrm{s} ) then the frequency at which the first maximum is observed is : A . ( 165 mathrm{Hz} ) в. ззо нz c. 495 нz D. 660 нz |
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55 | 27. In Young’s double-slit experiment, 30 fringes are obtained in the field of view of the observing telescope, when the wavelength of light used is 4000 Ă. If we use monochromatic light of wavelength 6000 X, the number of fringes obtained in the same field of view is (a) 30 (b) 45 (d) none of these (c) 20 muiment the concretion between |
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56 | In a Young’s double slit experiment D equals the distance of screen and dis the separation between the slit. The distance of the nearest point to the central maximum where the intensity is same as that due to a single slit, is equal to:- A. ( frac{D lambda}{d} ) в. ( frac{D lambda}{2 d} ) c. ( frac{D lambda}{3 d} ) D. ( frac{2 D lambda}{d} ) |
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57 | In a YDSE, if the incident light consists of two wavelengths ( lambda_{1} ) and ( lambda_{2} ), the slit separation is ( d ), and the distance between the slit and the screen is ( D ) the maxima due to each wavelength will coincide at a distance from the central maxima, given by A ( frac{lambda_{1}+lambda_{2}}{2 D d} ) в. ( _{text {LCM of }} frac{lambda_{1} D}{d} ) and ( frac{lambda_{2} D}{d} ) c. ( _{left(lambda_{1}+lambda_{2}right)} frac{2 D}{D} ) D. ( _{text {HCF of }} frac{lambda_{1} D}{d} ) and ( frac{lambda_{2} D}{d} ) |
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58 | When two tuning forks ( A ) and ( B ) are sounded together, 4 beats per second are heard. The frequency of the fork ( B ) is ( 384 H z . ) When one of the prongs of the fork ( A ) is filed and sounded with ( B ), then beat frequency increases, then frequency of the fork ( boldsymbol{A} ) is A. ( 380 H z ) в. 388 Нг c. 379 Н ( z ) D. ( 389 ~ H z ) |
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59 | In Young’s double slit experiment width sodium vapour lamp of wavelength 589 nm and the slits 0.589 mm apart, the half angular width of the central maximum is ( A cdot sin ^{-1}(0.01) ) B. ( sin ^{-1}(0.0001) ) ( c cdot sin ^{-1}(0.001) ) D. ( sin ^{-1}(0.1) ) |
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60 | In Young’s double slit experiment: A. only interference occurs B. only diffraction occurs c. both interference and diffraction occurs D. polarisation occurs |
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61 | Two waves of amplitudes ( A ) and ( 3 A ) are superposed and they have a phase difference of ( pi . ) What kind of interference is possible A. constructive interference B. Destructive interference c. Interference depends on wavelength difference D. Interference depends on frequency difference |
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62 | Polarisation of light was first successfully explained by: A. corpuscular theory B. Huygens’ wave theory c. Electromagnetic wave theory D. Planck’s theory |
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63 | Microwaves from a transmitter are directed normally toward a plane reflector. A detector moves along the normal to the reflector. Between positions of 14 successive maxima the detector travels a distance 0.14 m. The frequency of the transmitter is ( (c= ) ( 3 times 10^{8} m s^{-1} ) A. ( 1.5 times 10^{10} mathrm{Hz} ) в. ( 10^{10} mathrm{Hz} ) c. ( 3 times 10^{10} H z ) D. ( 6 times 10^{10} mathrm{Hz} ) |
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64 | 36. In Young’s double-slit experiment, the slit separation is 0.5 mm and the screen is 0.5 m away from the slit. For a monochromatic light of wavelength 500 nm, the distance of 3rd maxima from the 2nd minima on the other side of central maxima is (a) 2.75 mm (b) 2.5 mm (c) 22.5 mm (d) 2.25 mm |
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65 | A narrow tube is bent in the form of a circle of radius ( R, ) as shown in the figure. Two small holes ( S ) and ( D ) are made in the tube at the positions right angle to each other. A source placed at S generated a wave of intensity ( l_{0} ) which is equally divided into two parts : One part travels along the longer path, while the other travels along the shorter path. Both the part waves meet at the point D where a detector is placed. If a maxima is formed at the detector then, the magnitude of wavelength ( lambda ) of the wave produced is given by : This question has multiple correct options A . ( pi R ) в. ( frac{pi R}{2} ) c. ( frac{pi R}{4} ) D. ( frac{2 pi R}{3} ) |
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66 | Find the fringe width for the pattern obtained under given arrangement on the screen. ( ^{A} cdot frac{lambda f}{2 t} ) в. ( frac{lambda f}{t} ) c. ( frac{t f}{lambda} ) D. ( frac{t f}{2 lambda} ) |
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67 | A beam of natural light falls on a system of 6 Polaroids, which are arranged in succession such that each of the Polaroid is turned through ( 30^{circ} ) with respect to the proceeding the one. The percentage of incident intensity that passes through the system will be: ( mathbf{A} cdot 100 % ) B. ( 50 % ) ( c .30 % ) D. ( 12 % ) |
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68 | What is matter waves? Write any two characteristics of it. |
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69 | The wavefront of a light beam is given by the equation ( boldsymbol{x}+mathbf{2} boldsymbol{y}+mathbf{3} boldsymbol{z}=boldsymbol{c} ) (where ( c ) is arbitrary constant) then what is the angle made by the direction of light with the y-axis? A ( cdot cos ^{-2} frac{2}{sqrt{14}} ) B. ( cos ^{-1} frac{2}{sqrt{14}} ) ( mathrm{c} cdot cos ^{-3} frac{2}{sqrt{14}} ) D. ( cos ^{-4} frac{2}{sqrt{14}} ) |
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70 | In Young’s double slits experiment, if the separation between the slits is halved, and the distance between the slits and the screen is doubled, then the fringe width compared to the original one will be? A. Unchanged B. Halved c. Doubled D. Quadrupled E. Fringes will disappear |
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71 | If monochromatic red light is replaced by green light, then the fringe width: A . increases B. remains same c. can’t say D. decreases |
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72 | Pile of plates can be used to produce completely polarised light due to : A. Reflection B. Refraction c. Double refraction D. A and B |
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73 | In Young’s double slit experiment wavelength of light is 6000 A The the phase difference between the light waves reaching the third bright fringe from the central fringe will be: ( mathbf{A} cdot mathbf{0} ) в. ( 2 pi ) c. ( 4 pi ) D. ( 6 pi ) |
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74 | Angle of incidence is equal to the angle of reflection. A . Always B. Sometimes c. Under special condition D. Never |
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75 | wavefront and ( A O ) and ( B P ) the corresponding extreme rays of monochromatic light of wavelength ‘ ( lambda ). The value of angle ( theta ) for which the ray ( mathrm{BP} ) and the reflected ray OP interfere constructively is given by: A ( cdot cos theta=frac{3 lambda}{4 d} ) B. ( cos theta=frac{lambda}{4 d} ) ( mathrm{c} cdot sec theta=frac{lambda}{3 d} ) D ( sec theta=frac{2 lambda}{3 d} ) |
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76 | Visible light passing through a circular hole forms a diffraction disc of radius ( 0.1 mathrm{mm} ) on a screen. If ( mathrm{X} ) -ray is passed through the same set up, the radius of the diffraction disc will be A . zero B. 0.1 ( m m ) |
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77 | What is the Brewster angle for air to glass transition? (Refractive index of glass is 1.5 ). |
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78 | A single slit Fraunhoffer diffraction pattern is formed with white light. For what wavelength of light the third secondary maximum in the diffraction pattern coincides with the second secondary maximum in the pattern for red light of wavelength 6500 A? B . ( 4642 A^{circ} ) c. ( 4100 A^{circ} ) D. ( 4400 A^{circ} ) |
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79 | Wavelength of light used in an optical instrument are ( lambda_{1}=4000 hat{A} ) and ( lambda_{2}= ) ( mathbf{5 0 0 0} boldsymbol{A} ) then ratio of their respective resolving powers(corresponding to ( lambda_{1} ) and ( lambda_{2} ) ) is A. 16: 25 B. 9: ( c cdot 4: 5 ) D. 5: |
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80 | When the sun rays are incident at an angle of ( 60^{0} ) then intensity is ( I . ) What will be the intensity if the sun rays are incident at ( 30^{circ} ? ) A ( cdot frac{I}{sqrt{3}} ) B. ( sqrt{3} I ) c. ( 3 I ) D. ( frac{1}{3} ) |
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81 | In double slit experiment, when interference pattern due to whitelight is observed by an observer through a transparent glass of green colour, he finds black and green bright fringes. If green glass is replaced by violet colour glass, then: A. No interference pattern will appear B. Bright violet fringes will appear to be of smaller width than green fringes C. Bright violet fringes will appear to be of more width than green fringes D. Bright fringes will be produced of the same width as that of green fringes |
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82 | In YDSE, let ( A ) and ( B ) be two slits. Films of thicknesses ( t_{A} ) and ( t_{B} ) and refractive indices ( mu_{A} ) and ( mu_{B} ) are placed in front of ( A ) and ( B, ) respectively. If ( mu_{A} t_{A}=mu_{B} t_{B} ) then the central maxima will : A. Not shift B. Shift toward ( A ) c. shift toward ( B ) D. (b) if ( t_{B}>t_{A} ) and (c) if ( t_{B}<t_{A} ) |
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83 | In Young’s double slit experiment, the two slits act as coherent sources of equal amplitude a and of wavelength ( lambda ) In another experiment with the same set up, the two slits are source of equal amplitude ( n ) and wavelength ( lambda ), but are incoherent. The ratio of intensities of light at the mid point of the screen in the first case to that in the second case is A .2: 1 B . 1: 2 ( c cdot 3: 4 ) ( D cdot 4: 3 ) |
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84 | If the whole bi-prism experiment is immersed in water then the fringe width becomes, if the refractive indices of bi-prism material and water are 1.5 and 1.33 respectively, A. 3 times B. ( frac{3}{4} ) times c. ( frac{4}{3} ) times D. ( frac{1}{3} ) times |
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85 | A ( 600 n m ) light is perpendicularly incident on a soap film suspended in air. The film is ( 1.00 mu m ) thick with ( n= ) 1.35. Which statement most accurately describes the interference of light reflected by the two surfaces of the film? A. The waves are close to destructive interference B. The waves are close to constructive interference c. The waves show complete destructive interference D. The waves show complete constructive interference |
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86 | For a glass plate as a polariser with refractive index 1.633 , calculate the angle of incidence at which light is polarised. |
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87 | A plane wave front falls on a convex lens The emergent wave front: A. converges to a point B. diverges from a point c. does not suffer any refraction D. may or may not converge at point |
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88 | 16. In Young’s double slit experiment, one of the slit is wider than other, so that amplitude of the light from one slit is double of that from other slit. If I be the maximum intensity, the resultant intensity I when they interfere at phase difference o is given by (a) L (4 + 5 cosø (b) 5 (1+2 cos? ) c) ‘s(1+400) « ‘;{1+8 cm) (AIEEE 2012) |
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89 | of intensity ( I ) is incidents on a glass plate as shown, in the figure. Another identical glass plate is kept close to the first-one and parallel to it. Each glass plate reflects ( 25 % ) of the light incident on it and transmits the remaining. Then the ratio of the maximum and minimum intensities in the interference pattern formed by the two beams obtained after one reflection at each plate is A . 7: 1 B. 49: 1 c. 4: 1 D. 16: 9 |
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90 | An unpolarized beam of light is incident on a group of four polarizing sheets, which are arranged in such a way that the characteristic direction of each polarizing sheet makes an angle of ( 30^{circ} ) with that of the preceding sheet. The fraction of incident unpolarized light transmitted is A ( cdot frac{27}{128} ) B. ( frac{128}{27} ) c. ( frac{37}{128} ) D. ( frac{128}{37} ) |
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91 | What is wavefront? Describe Huygen’s theory of secondary wavelets. |
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92 | A polarizer -analyser set is adjusted such that the intensity of light coming out of the analyser is just ( 10 % ) of the original intensity. Assuming that the polarizer-analyser set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero, is: A . ( 90^{circ} ) в. ( 71.6^{circ} ) c. ( 18.4^{circ} ) D. ( 45^{circ} ) |
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93 | Anti-nodal curves represent the points joining: A. destructive interference B. constructive interference c. equal phase curves D. equal pressure curves E. zero pressure curves |
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94 | A fringe width of a certain interference pattern is ( beta=0.002 mathrm{cm} . ) What is the distance of ( 5^{t h} ) dark fringe from centre? ( mathbf{A} cdot 1 times 10^{-2} mathrm{cm} ) B. ( 11 times 10^{-2} mathrm{cm} ) ( mathrm{c} cdot 1.1 times 10^{-2} mathrm{cm} ) D. ( 3.28 times 10^{6} mathrm{cm} ) |
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95 | 2. The transverse nature of light is shown by (a) interference of light (b) refraction of light (c) polarisation of light (d) dispersion of light (AIEEE 2002) |
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96 | Two light waves of intensities ( ^{prime} I_{1}^{prime} ) and ( ^{prime} I_{2}^{prime} ) having same frequency pass through same medium at a time in same direction and interfere. The sum of the minimum and maximum intensities is ( mathbf{A} cdotleft(I_{1}+I_{2}right) ) B ( cdot 2left(I_{1}+I_{2}right) ) C ( cdotleft(left(sqrt{I}_{1}+sqrt{I}_{2}right)right) ) D. ( left(left(sqrt{I}_{1}-sqrt{I}_{2}right)right) ) |
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97 | In a Young’s double-slit experiment, the fringe width is ( beta . ) If the entire arrangement is now placed inside a liquid of refractive index ( mu ), the fringe width will become ( mathbf{A} cdot mu beta ) в. ( frac{beta}{mu} ) ( c cdot frac{beta}{mu+1} ) D. ( frac{beta}{mu-1} ) |
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98 | A narrow tube is bent in the form of a circle of radius ( R, ) as shown in the figure. Two small holes ( S ) and ( D ) are made in the tube at the positions right angle to each other. A source placed at S generated a wave of intensity ( l_{0} ) which is equally divided into two parts : One part travels along the longer path, while the other travels along the shorter path. Both the part waves meet at the point ( D ) where a detector is placed. If the minima is formed at the detector then, the magnitude of wavelength ( lambda ) of the wave produced is given by : This question has multiple correct options A. ( 2 pi R ) R R. ( 2 pi ) в. ( frac{3 pi R}{2} ) c. ( frac{2 pi R}{3} ) D. ( frac{2 pi R}{5} ) |
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99 | State and explain Brewster’s law. | 12 |

100 | Sets of travelling waves are given as shown in above figure Identify which set of waves has already been through interference? ( A cdot A ) B. B ( c cdot c ) D. E. |
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101 | 4. A plane wavefront traveling in a straight line in vacuum encounters a medium of refractive index u. At P, the shape of the wavefront is u (a) |
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102 | In the case of the waves from two coherent sources ( S_{1} ) and ( S_{2}, ) there will be constructive interference at an arbitrary point ( P ), the path difference ( boldsymbol{S}_{1} boldsymbol{P}-boldsymbol{S}_{2} boldsymbol{P} ) is then A ( cdotleft[n+frac{1}{2}right] lambda ) B. ( n lambda ) c. ( left[n-frac{1}{2}right] lambda ) D. ( frac{lambda}{2} ) |
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103 | In an interference pattern of two waves fringe width is ( beta . ) If the frequency of source is doubled then fringe width will become:- A ( cdot frac{1}{2} beta ) B. ( beta ) ( c cdot 2 beta ) D. ( frac{3}{2} ) |
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104 | A small coin is resting on the bottom of a beaker filled with a liquid. A ray of light from the coin travels upto the surface of the liquid and moves along its surface (see figure)How fast is the light travelling in the liquid? ( mathbf{A} cdot 1.2 times 10^{8} mathrm{m} / mathrm{s} ) B . ( 1.8 times 10^{8} mathrm{m} / mathrm{s} ) C ( .2 .4 times 10^{8} mathrm{m} / mathrm{s} ) D. ( 3.0 times 10^{8} mathrm{m} / mathrm{s} ) |
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105 | The ratio of the intensities at minima to the maxima in the Young’s double slit experiment is ( 9: 25 . ) Find the ratio of the widths of the two slits. |
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106 | In Young’s double slit expt. the distance between two sources is ( 0.1 mathrm{mm} ). The distance of the screen from th source is 20 cm. Wavelength of light used is 5460 A. The angular position of the first dark fringe is A ( cdot 0.08^{circ} ) B. ( 0.16^{circ} ) ( c cdot 0.20^{circ} ) D. ( 0.32^{circ} ) |
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107 | In Young’s double slit experiment the distance d between the slits ( S_{1} ) and ( S_{2} ) is ( 1 mathrm{mm} ). What should the width of each slit be ( operatorname{so~as~to~obtain~} 10^{t h} ) maxima of the double slit pattern within the central maximum of the single slit pattern? A. ( 0.9 mathrm{mm} ) B. 0.8 mm ( c .0 .2 mathrm{mm} ) D. 0.6 mm |
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108 | In the Young’s double slit experiment, intensities of black and bright fringes are 1 and 4 respectively, the ratio of amplitudes of sources will be : A . 1: 1 B. 1: 2 c. 3: 1 D. 1: 4 |
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109 | If the point object is moved away from mirror normal to screen then A. fringe width will increase B. fringe width will decrease c. fringe width will first increase then decrease D. Remain unchanged |
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110 | A beam of light ( A O ) is incidents on a glass slab ( (mu=1.54) ) in a direction as shown, in the Fig. The reflected ray ( O B ) is passed through a Nicol prism. On rotating the Nicol prism we observe the A. the intensity is reduced to zero and remains zero B. the intensity reduces somewhat and rise again c. there is no change in intensity D. the intensity is gradually to reduces to zero and then again it increases |
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111 | The maximum number of possible interference maxima, for slit-separation equal to twice the wavelength,in Young’s double-slit experiment, is A . Infinite B. Five c. Three D. zero |
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112 | A plane wave of wavelength ( 6250 A ) is incident normally on a slit of width ( 2 x ) ( 10^{-2} mathrm{cm} . ) The width of the principal maximum on a screen distant ( 50 mathrm{cm} ) will be A. 312.5 ( times 10^{-3} mathrm{cm} ) В. 32.5 ( times 10^{-3} mathrm{m} ) c. ( 312.5 times 10^{-3} mathrm{m} ) D. 312 m |
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113 | Assume 100 pm ( X ) -ray beam is passed through YDSE. Interference pattern is observed on a photographic plate placed ( 40 mathrm{cm} ) away from the slits. What should be the separation between the slits so that the separation between two successive maxima is ( 0.1 mathrm{mm} ) A ( .4 mu m ) в. ( 0.4 mu m ) ( c .4 n m ) D. ( 40 mu m ) |
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114 | In Young’s double slit experiment. the fringe width with light of wavelength ( mathbf{0} ) ( 6000 A ) is ( 3 mathrm{mm} ). The fringe width, when the wavelength of light is changed to ( 4000 A ) is ( A cdot 3 m m ) B. ( 1 mathrm{mm} ) ( c cdot 2 m m ) D. ( 4 mathrm{mm} ) |
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115 | Three waves are given below. Sound waves Il. Visible light waves III. X-rays Which of the above waves cannot be polarised? A. I only B. III only c. I and II only D. I and III only E. I, II and III |
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116 | In YDSE, find the missing wavelength in front of one of the slits. ( ^{A} cdot frac{d^{2}}{2 D} ) B. ( frac{2 d^{2}}{D} ) c. ( frac{d^{2}}{3 D} ) D. ( frac{d^{2}}{4 D} ) |
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117 | In the propagation of polarised light waves, the angle between the plane of vibration and the plane of polarization is A ( cdot 0^{circ} ) B. 90 c. 45 D. ( 180^{circ} ) |
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118 | The redistribution of intensity on account of the superposition of two waves is called as: A. Refraction B. Polarisation c. Interference D. Non of these |
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119 | In a two-slit experiment, with monochromatic light, fringes are obtained on a screen placed at some distance from the slits. If the screen is moved by ( 5 times 10^{-2} mathrm{m} ) towards the slits, the change in fringe width is ( 10^{-3} mathrm{m} ) The the wavelength of light used is (given that distance between the slits is ( 0.03 mathrm{mm} ) ( A cdot 4500 stackrel{circ}{A} ) B . 5000 , c. 5500 , D. 6000 , |
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120 | Newton’s ring pattern in reflected system, viewed under white light consists of A. Equally spaced bright and dark bands with central dark spot B. Equally spaced bright and dark bands with central white spot C. A few coloured rings with central dark spot D. A few coloured rings with central white spot |
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121 | According to Huygens, the ether medium pervading entire universe is A . Less elastic and more dense B. Highly elastic and less dense c. Not elastic D. Much heavier |
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122 | An isotropic point source emits light. screen is situated at a given distance. If the distance between sources and screen is decreased by ( 2 % ), illuminance will increase by: A . ( 1 % ) B. 2% ( c .3 % ) D. ( 4 % ) |
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123 | A mixture of light, consisting of wavelength 590nm and an unknown wavelength, illuminates Young’s double slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of known light coincides with the 4 th bright fringe of the unknown light. From this data, the wavelength of the unknown light is A. ( 885.0 mathrm{nm} ) B. 442.5 nm c. ( 776.8 mathrm{nm} ) D. 393.4 nm |
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124 | Choose the correct statement A. Brewster’s angle is independent of the wavelength of light. B. Brewster’s angle is independent of nature of reflecting the surface. C. Brewster’s angle is different for different wavelengths. D. Brewster’s angle depends on the wavelength but not on the nature of reflecting the surface. |
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125 | ( S_{1} ) and ( S_{2} ) are two coherent sources of sound having no initial phase difference. The velocity of sound is 330 ( mathrm{m} / mathrm{s} . ) No maxima will be formed on the line passing through ( S_{2} ) and perpendicular to the line joining ( boldsymbol{S}_{1} ) and ( S_{2} . ) If the frequency of both the sources is : A. 330 ( mathrm{Hz} ) в. 120 Н ( z ) ( c cdot 100 mathrm{Hz} ) D. 220 нz |
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126 | Huygens’s concept of secondary wave A. allows us to find the focal length of a thick lens B. is a geometrical method to a find a wavefront ( mathrm{C} ). is used to determine the velocity of light D. is used to explain polarisation |
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127 | A source of light suspended above a circular table at a height equal to the radius of the table gives an intensity at the centre of the table, the intensity at the edge of the table would be (Assuming illuminance remains the same) A . 0.251 B. 0.5 । c. 0.71 D. 2.81 |
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128 | In a Young’s double slit experiment, constructive interference is produced at a certain point ( P . ) The intensities of light at ( boldsymbol{P} ) due to the individual sources are 4 and 9 units. The resultant intensity at point ( boldsymbol{P} ) will be- A. 13 units B. 25 units c. ( sqrt{97} ) units D. 5 units |
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129 | In YDSE distance between slits and screen is ( 1.5 mathrm{m} ). When light of wavelength 500nm is used then 2nd bright fringe is obtained on screen at a distance of 10mm from the central bright fringe. What will be the shift in the 2nd bright fringe of the light of wavelength 550nm is used? ( A cdot 2 m m ) B. ( 1 mathrm{mm} ) c. ( 1.5 mathrm{mm} ) D. ( 1.1 mathrm{mm} ) |
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130 | Monochromatic light of wavelength ( mathbf{5 8 9} ) nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) Reflected, and (b) Refracted light? Refractive index of water is 1.33 |
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131 | In the light emerging from calcite crystal: A. Both 0 -ray and E-ray are partially polarised B. Both O-ray and E-ray are completely polarised C. O-ray is partially polarised and E-ray is completely polarised. D. O-ray is completely polarised and E-ray is partially polarised. |
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132 | How many times will he hear a minimum in sound intensity? |
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133 | The interference of light was first demonstrated experimentally by A. sir Isaac Newton B. Michelson c. Fraunhoffer D. Thomas Young |
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134 | In YDSE The intensity of central bright fringe is ( 8 m W / m^{2} . ) What will be the intensity at ( lambda / 6 ) path difference? ( mathbf{A} cdot 8 m W / m^{2} ) в. ( 6 m W / m^{2} ) ( mathbf{c} cdot 4 m W / m^{2} ) ( mathbf{D} cdot 2 m W / m^{2} ) |
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135 | Which letter represents the wavelength of the light in the Young’s double slit experiment? ( A cdot A ) B. B ( c . c ) D. ( E ) |
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136 | In the case of linearly polarized light, the magnitude of the electric field vector A. is parallel to the direction of propagation B. does not change with time c. increases linearly with time D. varies periodically with time |
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137 | What is the difference between polarised light and unpolarised light? |
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138 | Assertion: Radio waves can’be polarised. Reason: Sound waves in air are |
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139 | Two coherent sources of wavelength ( 6.2 times 10^{-7} mathrm{m} ) produce interference. The path difference corresponding to ( 10^{t h} ) order maximum will be? A ( .6 .2 times 10^{-6} mathrm{m} ) В. ( 3.1 times 10^{-6} mathrm{m} ) c. ( 1.5 times 10^{-6} mathrm{m} ) D. ( 12.4 times 10^{-6} mathrm{m} ) |
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140 | Sunlight is reflected from a calm lake. The reflected light is ( 100 % ) polarized at a certain instant. The angle between the sun light and the surface of lake is ( (mu ) of water is ( frac{4}{3} ) ) ( left(tan ^{-1}left(frac{4}{3}right)=53^{circ} 4^{prime}right) ) A .90 В. ( 53^{circ} 4^{prime} ) ( mathbf{c} cdot 36^{circ} 56^{prime} ) D. 45 |
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141 | In studying diffraction pattern of different obstacles, the effect of: A. full wave front is studied B. portion of a wave front is studied c. waves from two coherent sources is studied D. waves from one of the coherent source is studied |
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142 | Newton postulated his corpuscular theory of light on the basis of A. newton’s rings B. rectilinear propagation of light c. colour through thin films D. dispersion of white light into colours |
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143 | In Fraunhofer diffraction experiment, ( boldsymbol{L} ) is the distance between screen and the obstacle, ( b ) is the size of obstacle and ( A ) is wavelength of incident light. The general condition for the applicability of Fraunhofer diffraction is ( ^{mathrm{A}} cdot frac{b^{2}}{L lambda} gg 1 ) B. ( frac{b^{2}}{L lambda}=1 ) c. ( frac{b^{2}}{L lambda} ll 1 ) D. ( frac{b^{2}}{L lambda} neq 1 ) |
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144 | 4. The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young’s double-slit experiment is (a) infinite (b) five (c) three (d) zero (AIEEE 2004) |
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145 | Resolving power of a telescope increases with A. increase in focal length of eye-piece B. increase in focal length of objective C. increase in aperture of eye piece D. increase in aperture of objective |
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146 | Explain why the intensity of light coming out of a polaroid does not change irrespective of the orientation of the pass axis of the polaroid. |
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147 | Sound signal is sent through a composite tube as shown in figure. The radius of the semicircle is r. Speed of sound in air is ( V ). The source of sound is capable to generate frequencies in the range ( f_{1} ) to ( f_{2}left(f_{2}>fright) . ) If ‘n’ is an integer then frequency for maximum intensity is given by : ( A cdot frac{n V}{r} ) B. ( frac{n V}{r(pi-2)} ) ( mathbf{c} cdot 7 V / r ) D. ( frac{n V}{(r-2) pi} ) |
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148 | In a Fresnel’s bi-prism experiment, the fringe of width 0.05 mm is observed on a screen at a distance of ( 1.5 m ) from the source. When a convex lens is placed between the source and the screen, for two positions of the lens image of interfering sources are produced on the screen. The separation between the two images being 0.04 and ( 0.01 m m ) respectively. The wavelength of light used is ( mathbf{A} cdot 6.67 n m ) B. ( 0.667 n m ) ( c .667 n m ) D. ( 667 A^{circ} ) |
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149 | In Young’s interference experiment, if the slits are of unequal width, then A. no fringes will be formed B. the positions of minimum intensity will not be completely dark C. bright fringe as displaced from the original central position D. distance between two consecutive dark fringes will not be equal to the distance between two consecutive right fringes. |
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150 | In Young’s double slit experiment, the slits are ( 2 mathrm{mm} ) apart are illuminated by photons of two wavelengths ( boldsymbol{I}_{1}= ) ( 12000 A ) and ( I_{2}=10000 A ) at what minimum distance from the common central bright fringe on the screen ( 2 mathrm{m} ) from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other? ( A cdot 8 m m ) B. 6 mm ( c cdot 4 m m ) D. 3 mm |
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151 | Where ( d ) is width of the strips. Fringe visibility is defined as ( ^{A} cdot frac{I_{m a x}-I_{m i n}}{I_{m a x}+I_{m i n}} ) B. ( frac{I_{max }+I_{min }}{I_{max }-I_{min }} ) c. ( frac{I_{max }-I_{min }}{I_{max }} ) D. ( frac{I_{max }+I_{min }}{I_{max }+I_{min }} ) |
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152 | When petrol drops from a vehicle fall over rain water on road surface, colours are seen because of: A. dispersion of light B. interference of light c. scattering of light D. absorption of light |
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153 | Consider the following statements A & B and identify correct choice in the given answers (A) When light falls on two polaroid sheets having their axes mutually perpendicular, it is completely extinguished. (B) When polyvinyl alcohol is subjected to a large strain the molecules get oriented parallel to the direction of strain and material becomes double refractive. A . A & B are correct B. Both A & B are wrong C. A correct B wrong D. A wrong B correct |
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154 | 67. A parallel beam of white light is incident on a thin film of air of uniform thickness. Wavelengths 7200 Å and 5400 A are observed to be missing from the spectrum of reflected light viewed normally. The other wavelength in the visible region missing in the reflected spectrum is (a) 6000 Å (b) 4320 Å (c) 5500 Å (d) 6500 Å |
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155 | Tenth fringe of wavelength ( 4000 A^{circ} ) coincides with ( 8 t h ) fringes of wavelength ( lambda ). Then ( lambda ) is ( mathbf{A} cdot 50 n m ) B. ( 555 n m ) c. 450 n ( m ) D. none |
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156 | If two waves are moving in same medium and meet at the same time and both are in the same phase. It will be: A. Reflection B. Refraction C. Diffraction D. Constructive interference E. Destructive interference |
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157 | On reflection from a plane surface, the following two characteristics get changed: This question has multiple correct options A. wavelength B. Frequency c. velocity D. Amplitude |
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158 | In the set up shown, the two slits ( S_{1} ) and ( S_{2} ) are not equidistant from the slit S. The central fringe at 0 is then A. always bright B. always dark C. either dark or bright depending on the position of D. neither dark nor bright |
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159 | In Young’s double slit experiment, the two slits act as coherent sources of equal amplitude ( A ) and wavelength ( lambda ). In another experiment with the same set up the two slits are same of equal amplitude of wavelength ( lambda ) but are incoherent. The ratio of intensity of light at the mid point of the screen in the first to the second case is? A . 4: 1 B . 2: 1 ( c cdot 1: 1 ) D. 1: 2 |
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160 | When light is incidence on a diffraction grating, then the zero order maximum will be A. spectrum of the colours B. White c. one of the component colours D. Absent |
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161 | The wave theory of light, in its original form, was first postulated by. A. Isaac Newton B. Christian Huygens c. Thomas Young D. Augustin Jean Fresnel |
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162 | 6. In Young’s double-slit experiment, a monochromatic source is used. The shape of the interference fringes formed on the screen is (a) a parabola (b) a straight line (c) a circle (d) a hyperbola (AIEEE 2005) |
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163 | A source emits electromagnetic waves of wavelength ( 3 m . ) One beam reaches the observer directly and other after reflection from a water surface, travelling 1.5 m extra distance and with intensity reduced to ( frac{1}{4} ) as compared to intensity due to the direct beam alone. The resultant intensity will be. A ( cdotleft(frac{1}{4}right) ) fold B ( cdotleft(frac{3}{4}right) ) fold c. ( left(frac{5}{4}right) ) fold D. ( left(frac{9}{4}right) ) fold |
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164 | In YDSE, having slits of equal width, let ( beta ) be the fringe width and ( I_{0} ) be the maximum intensity. At a distance ( x ) from the central bright fringe, the intensity will be ( ^{mathbf{A}} cdot_{I_{0}} cos left(frac{x}{beta}right) ) B. ( _{I_{0} cos ^{2}} frac{2 pi x}{beta} ) c. ( _{I_{0} cos ^{2}} frac{pi x}{beta} ) D. ( frac{I_{0}}{4} cos ^{2} frac{pi x}{beta} ) |
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165 | To measure the-roughness of the surface of a material, which of the following microscope is preferred for better result output? A. Compound microscope B. Electron microscope c. Atomic force microscope D. None of the above |
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166 | In Young’s double slit eperiment two disturbances arriving at a point P have phase difference of ( frac{pi}{3} . ) The intensity of this point expressed as a fraction of maximum intensity ( I_{0} ) is then A ( cdot frac{3}{2} I_{0} ) в. ( frac{1}{2} I_{0} ) c. ( frac{4}{3} I_{0} ) D. ( frac{3}{4} I_{0} ) |
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167 | The minimum non-zero distance on screen from central maxima where both the wave are going to produce maxima together A . ( 2000 mu ) m в. ( 3600 mu ) и c. ( 4320 mu ) m D. ( 2160 mu mathrm{m} ) |
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168 | A plane polarized light passed through successive polarizers which are rotated by ( 30^{circ} ) with respect to each other in the clockwise direction. Neglecting absorption by the polarizers and given that the first polarizer’s axis is parallel to the plane of polarization of the incident light, the intensity of light at the exit of the fifth polarizer is closest to. A. Same as that of the incident light B. 17.5% of the incident light c. ( 30 % ) of the incident light D. zero |
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169 | Estimate the distance for which ray optics is good approximation for an aperture of 4 mm and wavelength ( 400 n m ) |
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170 | The condition for destructive interference is phase difference should be equal to A. odd integral multiple of ( pi ) B. Integral multiple of ( pi ) c. odd integral multiple of half ( pi ) D. Integral multiple of half ( pi ) |
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171 | The separation between two coherent point sources is ( 3 lambda . ) On a line perpendicular to ( S_{1} S_{2} ) and passing through ( S_{2} ). Find the smallest distance where minimum of intensity occurs: A ( cdot frac{11 lambda}{20} ) B. ( frac{lambda}{2} ) c. ( frac{9 lambda}{20} ) D. ( frac{35 lambda}{4} ) |
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172 | The intensity at the maximum in a Young’s double slit experiment is ( boldsymbol{I}_{mathbf{0}} ) Distance between two slits is ( d=5 lambda ) ,where ( lambda ) is the wavelength of light used in the experiment. What will be the intensity in front of one the slits on the screen place at a distance ( mathrm{D}=2 mathrm{m} ) |
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173 | Identify which of the following best describe diffraction. Diffraction occurs when they: A. travel around an object or through an opening. B. transition from one medium to another c. bounce off the surface of an object D. resonate with the molecules in a medium. E. pass through a medium unchanged |
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174 | The intensity of the light coming from one of the sites in a Young’s double slit experiment in the intensity from the other slit. Determine the ratio of the maximum intensity to the minimum intensity in the interference fringe pattern observed. |
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175 | The phenomena which is not explained by Huygen’s construction of the wavefront A. reflection B. diffraction c. refraction D. origin of spectrata |
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176 | State Huygens’ principle. | 12 |

177 | Assertion Two point coherent sources of light ( boldsymbol{S}_{1} ) and ( S_{2} ) are placed on a line as shown in figure. ( P ) and ( Q ) are two points on that line. If at point ( boldsymbol{P} ) maximum intensity is observed, then maximum intensity should also be observed at ( Q ) Reason In the figure, the distance ( left|boldsymbol{S}_{1} boldsymbol{P}-boldsymbol{S}_{2} boldsymbol{P}right| ) is equal to distance ( left|boldsymbol{S}_{1} boldsymbol{Q}-boldsymbol{S}_{2} boldsymbol{Q}right| ) [ vec{Q} quad overrightarrow{s_{1}} quad dot{S_{2}} quad dot{P} ] 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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178 | What is the path difference of destructive interference: A ( . n lambda ) B. ( n(lambda+1) ) c. ( frac{(n+1) lambda}{2} ) D. ( frac{(2 n+1) lambda}{2} ) |
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179 | The wavefront of a light beam is given by the equation ( x+2 y+3 z=c ) (where ( c ) is arbitrary constant of light). What is the angle made by the light with the ( y- ) axis is ( ^{A} cdot cos ^{-1} frac{1}{sqrt{14}} ) B. ( sin ^{-1} frac{2}{sqrt{14}} ) ( ^{mathrm{c}} cdot cos ^{-1} frac{2}{sqrt{14}} ) D. ( sin ^{-1} frac{3}{sqrt{14}} ) |
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180 | In a single slit diffraction pattern, ( (a) ) the intensity ( I, ) at a point where the total phase difference between the wavelets from top to bottom of the slit is 66 rad. (b) If this point is ( 7^{0} ) away from the central maxima. Find the width of the slit. Given: ( lambda=600 n m ) |
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181 | Assertion (A): Corpuscular theory fails in explaining the velocity of light in air to water. Reason (R) : According to corpuscular theory, light should travel faster in denser media than in rarer media. |
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182 | (a) In Young’s double slit experiment, derive the condition for (i) constructive interference and (ii) destructive interference at a point on the screen. (b) ( A ) bream of light consisting of two wavelengths, ( 800 n m ) and ( 600 n m ) is used to obtain the interference fringes in a Young’s double slit experiment on a screen placed ( 1.4 m ) away. If the two slits are separated by ( 0.28 n m ) calculate the least distance from the central bright maximum where the bright fringes of the two wavelengths coincide. |
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183 | Angular width of central maxima of a diffraction pattern of a single slit does not depend upon A. Distance between slit and source B. Wavelength of the light used c. width of slitt D. Frequency of light used |
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184 | A radio transmitting station operating at a frequency of 120 MHz has two identical antennas that radiate in phase. Antenna ( B ) is ( 9 m ) to the right of antenna ( A . ) Consider point ( P ) at ( a ) horizontal distance ( x ) to the right of antenna ( A ) as shown figure. The value of ( x ) and order for which the constructive interference will occur at point ( boldsymbol{P} ) are This question has multiple correct options ( mathbf{A} cdot x=14.95 m, n=1 ) B ( . x=5.6 m, n=2 ) ( mathbf{c} cdot x=1.65 m, n=3 ) D. ( x=0, n=3.6 ) |
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185 | Calculate the number of fringes. A . 10 B. 20 ( c .30 ) D. 40 |
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186 | Monochromatic light of wavelength ( 4500 A ) falls on slit of width ( ^{prime} a^{prime} . ln ) diffraction pattern second maxima deviates through ( 30 . ) The slit width is |
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187 | Assertion Two coherent point sources of light having non-zero phase difference are separated by a small distance. Then, on the perpendicular bisector of line segment joining both the point sources, constructive interference cannot be obtained. Reason For two waves from coherent point sources to interfere constructively at a point, the magnitude of their phase difference at that point must be ( 2 m pi ) (where ( m ) is a non-negative integer) 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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188 | The phases of the light wave at ( c, d, e ) and ( f ) are ( phi_{c}, phi_{d}, phi_{e} ) and ( phi_{f} ) respectively. It is given that ( phi_{c} neq phi_{r} ) ( mathbf{A} cdot phi_{c} ) cannot be equal to ( phi_{d} ) B. ( phi_{d} ) cannot equal to ( phi_{mathrm{e}} ) ( mathbf{c} cdotleft(phi_{d}-phi_{f}right) ) is equal to ( left(phi_{c}-phi_{e}right) ) ( mathbf{D} cdotleft(phi_{d}-phi_{c}right) ) is not equal to ( left(phi_{f}-phi_{e}right) ) |
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189 | When waves of same intensity from two coherent sources reach a point with zero path different the resulting intensity is ( mathrm{K} ). When the above path difference is ( lambda / 4 ) the intensity becomes ( A cdot K ) B. K/2 ( c cdot k / 4 ) D. K/8 |
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190 | Which of the following phenomena support the wave theory of light? (a) Scattering (b) Interference ( (c) ) Diffraction Velocity of light in a denser medium is less (d) than the velocity of light in the rarer medium. ( A cdot A, B, C ) B. A, B, D ( c cdot B, C, D ) D. ( A, C, ) |
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191 | A calcite crystal is placed over a dot on a piece of paper and rotated. On seeing through the calcite, one will see : A. one dot B. Two stationary dots c. Two rotating dots D. One dot rotating about the other |
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192 | A primary monochromatic coherent source is used in ( Y D S E ) and half of the space between the primary source and the slits is filled with a transparent liquid of refractive index ( mu ) with respect to air, such that path of the wave ( S S_{2} ) is through this liquid. Everywhere else there is air and slits are sealed with equal glass plates. Find the ocation of central maximum. |
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193 | When an unpolarized light of intensity ( I_{0} ) is incident on a polarizing sheet, the intensity of the light which does not get transmitted is: A ( cdot frac{1}{2} I_{0} ) в. ( frac{1}{4} I_{0} ) c. zero D. ( I_{0} ) |
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194 | Find the angular fringe width in Young’s double slits experiments with a bluegreen light of wavelength 6000 A. The separation between the slits is ( 3.0 x ) ( 10^{-3} m ) |
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195 | In young’s experiment, the source of red light of wavelength ( 7 times 10^{-7} ) m. When a thin glass plate of refractive index 1.5 at this wavelength is put in the path of one of the interfering beams, the central fringe shifts by ( 10^{-3} m ) to the position previously occupied by the 5 th bright fringe. If the thickness of the plate is ( boldsymbol{X} boldsymbol{mu} boldsymbol{m} ) Find ( X ? ) |
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196 | 41. What will be the angle of diffracting for the first minimum due to Fraunhofer diffraction with sources of light of wave length 550 nm and slit of width 0.55 mm? (a) 0.001 rad (b) 0.01 rad (c) 1 rad (d) 0.1 rad |
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197 | Polarisation of light establishes A. corpuscular theory of light B. quantum nature of light c. transverse nature of light D. all of the above |
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198 | A source emitting wavelengths ( 480 mathrm{nm} ) and ( 600 mathrm{nm} ) is used in YDSE. The separation between the slits is 0.25 mm. The interference is observed ( 1.5 mathrm{m} ) away from the slits. The linear separation between first maxima of the two wavelengths is : A. ( 0.72 mathrm{mm} ) в. 0.72 ст c. ( 7.2 mathrm{cm} ) D. ( 7.2 mathrm{mm} ) |
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199 | Sets of travelling waves are given as shown in above figure. Identify which of the following set of the wave will soon show destructive interference? ( A cdot A ) B. B ( c cdot c ) D. E. |
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200 | White light is normally incidents on a soap film. The thickness of the film is ( 0.5 mu m ) and its refractive index is 1.33 Which wave length will be reflected maximum in the visible region? A ( .26600 A^{circ} ) B . ( 8860 A^{circ} ) ( mathrm{c} .5320 A^{circ} ) D. ( 3800 A^{circ} ) |
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201 | In a plane transmission grating, the width of a ruling is ( 12000 A ) and the width of a slit is ( 8000 A ), the grating element is: A. ( 20 mu m ) В. ( 2 mu m ) c. ( 200 mu m ) D. ( 10 mu m ) |
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202 | In the Fresnel bi-prism experiment, the refractive index for the bi-prism is ( mu= ) ( 3 / 2 ) and fringe width obtained is ( 0.4 m m . ) If the whole apparatus is immersed as such in water then the fringe width will become(refractive index of water is ( 4 / 3 ) ). ( mathbf{A} cdot 0.3 m m ) B. ( 0.225 mathrm{mm} ) ( c .0 .4 m m ) D. ( 1.2 m m ) |
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203 | An analyser examines two adjacent plane-polarised beams A and B whose planes of vibration are mutually perpendicular. In one position of the analyser, beam B shows zero intensity. From this position, a rotation of ( 30^{circ} ) shows the two beams as matched in intensity. The intensity ratio I_(A ( } / I_{-}{B} ) of the two beams is A ( cdot sqrt{3} ) B. ( 1 / 3 ) c. ( 1 / sqrt{2} ) |
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204 | If ( I_{0} ) is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled A. ( I_{0} ) B. ( frac{I_{0}}{2} ) ( c cdot 2 I_{0} ) D. ( 4 I_{0} ) |
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205 | To observe diffraction, the size of the obstacle A. should be ( lambda / 2 ), where ( lambda ) is the wavelength. B. should be of the order of wavelength. C. has no relation to wavelength. D. should be much larger than the wavelength. |
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206 | Derive the formula ( omega=frac{D lambda}{2} ) for fringe width in Young’s double slit experiment The symbols used have their usual meanings. |
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207 | An analyser is inclined to a polarizer at an angle of ( 30^{circ} . ) the intensity of light emerging from the analyser is ( frac{1}{n} ) of that is incident on the polarizer. Then ( n ) is equal to A .4 B. ( frac{4}{3} ) ( c cdot frac{8}{3} ) D. ( frac{1}{4} ) |
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208 | A 1. A wave front AB passing through a system C emerges as DE. The system C could be (a) a slit (b) a biprism (c) a prism (d) a glass slab B |
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209 | Phase difference ( (phi) ) and path difference ( (delta) ) are related by : A ( cdot frac{2 pi}{lambda} delta ) в. ( frac{pi}{2 lambda} delta ) ( c cdot frac{lambda}{2 pi} delta ) D. ( frac{2 lambda}{pi} ) |
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210 | The wavefront is a surface in which A. all points are in the same phase B. there is a pair of points in opposite phase C cdot there is a pair of points with phase difference ( left(frac{pi}{2}right) ) D. there is no relation between the phases |
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211 | Who amongst the following used corpuscular theory to explain the nature of light? A. Max Planck B. Newton c. Young D. Einstein |
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212 | Match the following: PART-A PART-B |
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213 | Polaroid glass is used in sun glasses because A. It reduces the light intensity to half on account of polarisation B. It is fashionable c. It has good colour D. It is cheaper |
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214 | fa maxima is formed at a detector then the magnitude of wavelength ( lambda ) of the wave produced is given by A . ( pi R ) в. ( frac{pi R}{2} ) с. ( frac{pi R}{4} ) D. all of these |
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215 | What is the difference between polarised light and unpolarished light based on the direction of electric vector ( (vec{E}) ? ) |
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216 | White light reflected from a soap film(Refractive Index=1.5) has a maxima at 600 nm and a minima at 450 nm with no minimum in between. Then the thickness of the film is ( times 10^{-7} mathrm{m} ) A . 1 B. 2 ( c cdot 3 ) D. 4 |
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217 | If in a birefracting crystal the magnitude ( E_{x} ) and ( E_{y} ) are equal and phase angle between the two is ( 60^{0} ) then the waves are A. linearly polarised B. plane polarised C. circularly polarised D. elliptically polarised |
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218 | When exposed to sunlight, thin films of oil on water often exhibit brilliant colours due to the phenomenon of A. the dispersion B. the interference c. the diffraction D. the angular acceleration |
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219 | A Plane polarized light is incidents on an analyzer. The intensity then becomes three-fourth. The angle of the axis of the analyzer with the beam is A ( cdot 30^{circ} ) B ( .45^{circ} ) ( c cdot 60^{circ} ) D. zero |
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220 | An unpolarized light beam is incident on a surface at an angle of incidence equal to Brewsters angle. Then, A. the reflected and the refracted beam are both partially polarized B. the reflected beam is partially polarized and the refracted beam is completely polarized and are at right angles to each other C. the reflected beam is completely polarized and the refracted beam is partially polarized and are at right angles to each other D. both the reflected and the refracted beams are completely polarized and are at right angles to each other. |
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221 | Dichorism means A. selective absorption of unpolarised light. B. selective absorption of dispersed light. C . selective absorption of scattered light. D. selective absorption of one of the polarised component. |
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222 | A travelling acoustic wave of frequency ( 500 mathrm{Hz} ) is moving along the positive ( x ) direction with a velocity of ( 300 m s^{-1} ) The phase difference between two points ( x_{1} ) and ( x_{2} ) is ( 60^{circ} . ) Then the minimum separation between the two pints is ( mathbf{A} cdot 1 mathrm{mm} ) B. ( 1 mathrm{cm} ) c. ( 10 mathrm{cm} ) D. ( 1 mathrm{m} ) |
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223 | Q Type your question radius of the semicircle is ( r . ) The speed of sound in air is ( v ). The source of sound is capable of generating frequencies in the range ( f_{1} ) to ( f_{2}left(f_{2}>f_{1}right) . ) If ( n ) is an integer, frequency for maximum intensity is given by : A ( cdot frac{n v}{r} ) B. ( frac{n v}{r(pi-2)} ) c. ( frac{n v}{pi r} ) D. ( frac{n v}{(r-2) pi} ) |
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224 | Consider the optical system shown in the figure that follows. The point source of light ( S ) is having wavelength equal to lambda. The light is reaching screen only after reflection. For point ( boldsymbol{P} ) to be ( 2^{n d} ) maxima the value of ( lambda ) would be ( (D>>d ) and ( boldsymbol{d}>>boldsymbol{lambda}) ) A ( cdot frac{12 d^{2}}{D} ) B. ( frac{6 d^{2}}{D} ) c. ( frac{3 d^{2}}{D} ) D. ( frac{24 d^{2}}{n} ) |
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225 | 6. In Young’s double-slit experiment, a monochromatic source is used. The shape of the interference fringes formed on the screen is (a) a parabola (b) a straight line (c) a circle (d) a hyperbola (AIEEE 2005) |
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226 | If the first minima in Young’s double-slit experiment occurs directly in front of the slits (distance between slit and ( operatorname{screen} D=12 c m ) and distance between slits ( d=5 c m ) ), then the wavelength of the radiation used can be ( A cdot 2 c m ) в. 4 ст c. ( _{overline{3}^{c m}} ) ( stackrel{-4}{3}^{c m} ) |
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227 | What happens to the fringe pattern, if in the path of one of the slits a glass plate which adsorbs ( 50 % ) energy is interposed? A. brightness of fringes will decrease but the dark fringe will become brighter B. No fringes are observedd c. The frings width decrease D. None of the above |
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228 | Two sound waves travel out from a common point have frequencies ( 30 mathrm{Hz} ) and ( 40 mathrm{Hz} ) respectively. Calculate the phase difference between them after 0.8 second? A. zero B. ( c cdot frac{5 Pi}{2} ) D. 5Pi |
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229 | composite tube as shown in the Figure 14.24. The radius of the semicircular portion of the tube is ( r . ) The speed of sound in air is ( v . ) The source of sound is capable of giving sound of varied frequency. If ( n ) is an integer then frequency for maximum intensity is given by: ( mathbf{A} cdot n v / r ) в. ( n v / r(pi-2) ) c. ( n v / pi r r ) D. ( n v / pi(r-2) ) |
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230 | Young’s double slit experiment is carried out by using green, red and blue light, one color at a time. The fringe widths recorded are ( beta_{G}, beta_{R}, beta_{B} ) respectively. Then ( mathbf{A} cdot beta_{G}>beta_{B}>beta_{R} ) в. ( beta_{B}>beta_{G}>beta_{R} ) c. ( beta_{R}>beta_{B}>beta_{G} ) D. ( beta_{R}>beta_{G}>beta_{B} ) |
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231 | The class of diffraction in which incident and diffracted wave fronts are planar is called: A. Fresnel diffraction B. Fraunhofer diffraction c. Huygens’ diffraction D. Newton’s diffraction |
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232 | The parameter which does not change during polarisation of light is? A. Intensity of light wave B. Frequency of light wave c. wavelength of light wave D. Phase |
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233 | Find the fringe width of the fringe pattern A . ( 0.05 mathrm{cm} ) B. ( 0.25 mathrm{cm} ) ( c .0 .01 c m ) D. ( 0.1 mathrm{cm} ) |
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234 | Who proposed wave nature of light? A. Huygen B. Youngg c. Fresnel D. Maxwell |
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235 | A beam of light of wavelength 600 nm from a distant source falls on a single slit ( 1.00 m m ) wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringe on either side of the central maxima is : A ( .1 .2 mathrm{cm} ) B. ( 1.2 mathrm{mm} ) ( c .2 .4 m m ) D. ( 4.8 mathrm{mm} ) |
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236 | You have learnt in the text how Huygens principle leads to the laws of reflection and refraction. Use the same principle to deduce directly that a point object placed in front of a plane mirror produces a virtual image whose distance from the mirror is equal to the object distance from the mirror. | 12 |

237 | 22. In Young’s double-slit experiment, the two slits a coherent sources of equal amplitude A and of waveleno 2. In another experiment with the same setup, the two slits are sources of equal amplitude A and wavelength 2, but are incoherent. The ratio of intensity of light at the mid-point of the screen in the first case to that in the second case is (a) 1:1 (b) 1:2 (c) 2:1 (d) 4:1 |
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238 | A certain region of a soap bubble reflects red light of vacuum wavelength ( lambda=650 n m . ) What is the minimum thickness that this region of the soap bubble could have? Take the index of reflection of the soap film to be 1.41 A. ( 1.2 times 10^{-7} mathrm{m} ) B. ( 650 times 10^{-9} mathrm{m} ) c. ( 120 times 10^{7} m ) D. ( 650 times 10^{5} mathrm{m} ) |
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239 | 62. A light ray of frequency vand wavelength 2 enters a liquid of refractive index 3/2. The ray travels in the liquid with (a) frequency v and wavelength 2 (b) frequency v and wavelength (c) frequency v and wavelength 2. (d) frequency (3) vand wavelength 2. 1 |
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240 | When unpolarised light is incident on a plane glass plate at Brewster’s angle, then which of the following statements is correct? A. Reflected and refracted rays are completely polarised with their planes of polarisation parallel to each other B. Reflected and refracted rays are completely polarised with their planes of polarisation perpendicular to each other c. Reflected light is plane polarised but transmitted light is partially polarised D. Reflected light is partially polarised but refracted light is plane polarised |
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241 | A student is studying a book placed at the edge of a circular table of radius ( R ) A point source of light is suspended directly above the centre of the table. What should be the height of the lamp so that maximum illuminance is produced at the position of the book? A. ( R ) в. ( frac{R}{2} ) c. ( frac{R}{sqrt{2}} ) D. ( frac{R}{sqrt{3}} ) |
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242 | Are ( R_{1}, R_{2}, R_{3}, R_{4} ) and ( R_{5} ) nearly in phase A . yes B. na ( c . ) maintain a constant phase D. insufficient data to reply |
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243 | Ordinary light passes through two polarizing filters. The filters have been rotated so that their polarizing axes are oriented at ( 90^{circ} ) to each other, and no light gets through both of them. By adding a third polarizing filter so that there are three in a row, how might one cause light to pass through the three filters? A. Orient the third filter so that its polarizing axis is in front of the first B. Orient the third filter so that its polarizing axis is rotated ( 45^{circ} ) counter-clockwise relative to the seconds and place it in back of the second C. Orient the third filter so that its polarizing axis is rotated ( 45^{circ} ) clockwise relative to the first and place it in between the two filters D. Orient the third filter so that its polarizing axis is rotated ( 90^{circ} ) clockwise relative to the first and place it in front of the first E. Both A and B will work to allow light through |
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244 | Which one of the following property of light does not support wave theory of light A. Light obeys laws of reflection and refraction B. Light waves get polarised c. Light shows photoelectric effect D. Light shows interference |
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245 | Acceleration of 3 rd maxima w.r.t 3 rd maxima on other side of central maxima at ( t=3 s ) is A ( cdot 0.02 m s^{-2} hat{i} ) B. ( 0.03 m s^{-2} hat{i} ) ( mathbf{c} cdot 10 m s^{-2 hat{i}} ) D. ( 0.6 m s^{-2} hat{i} ) |
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246 | Assertion: Thin films such a soap bubble or a thin layer of oil on water show beautiful colours when illuminated by white light. Reason: It happens due to the interference of light reflected from the upper surface of the thin film. A. If both assertion and reason are true but the reason is the correct explanation of assertion B. If both assertion and reason are true but the reason is not the correct explanation ofassertion c. If assertion is true but reason is false D. If both the assertion and reason are false E. If reason is true but assertion is false |
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247 | In an experiment of single slit diffraction pattern, first minimum for red light coincides with first maximum of some other wavelength. If wavelength of red light is ( 6000 A^{circ} ), then wavelength of first maximum will be A ( .3000 A^{circ} ) B . ( 4000 A^{circ} ) c. ( 5000 A^{circ} ) D. ( 6000 A^{circ} ) |
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248 | Which of the following phenomena can be demonstrated by light. But not with sound waves in an air column? A . Reflection B. Diffraction c. Refraction D. Polarization |
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249 | The ratio of maximum and minimum intensities in an interference pattern is ( 36: 1 . ) The ratio of the amplitudes of the two interfering waves will be A . 5: 7 B. 7:4 ( c cdot 4: 7 ) D. 7:5 |
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250 | ILLUSTRATION 27.4 Monochromatic light of wavelength 5000 Å is used in YDSE, with slit width, d = 1 mm, distance between screen and slits, D = 1 m. If intensites at the two slits are I= 410 and 12 = 1o, find: (a) fringe width B; (b) distance of 5th minima from the central maxima on the screen; (c) intensity at y = 7 mm; (d) distance of the 1000th maxima; and (e) distance of the 5000th maxima. |
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251 | In diffraction pattern: A. The fringe widths are equal B. The fringe widths are not equal C. The fringes can not be produced D. The fringe width may or may not be equal |
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252 | With reference to polarization angle, ( boldsymbol{i}_{boldsymbol{p}}+boldsymbol{r}= ) |
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253 | (a) What is linearly polarized light. Describe briefly using a diagram how sunlight is polarised. (b) Unpolarised light is incident on a Polaroid. How would the intensity of transmitted light change when the Polaroid is rotated? |
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254 | (a) (i)’Two independent monochromatic sources of light cannot produce a sustained interference pattern’. Give reason (ii) Light wave each of amplitude “a” and frequency ” ( omega ” ), emanating from two coherent light sources superpose at a point. If the displacements due to these waves is given by ( y_{1}=a c o s omega t ) and ( boldsymbol{y}_{2}=boldsymbol{a} cos (boldsymbol{omega} boldsymbol{t}+boldsymbol{phi}) ) where ( boldsymbol{phi} ) is the phase difference between the two, obtain the expression for the resultant intensity at the point. (b) In Young’s double slit experiment, using monochromatic light of wavelength ( lambda ), the intensity of light at a point on the screen where path difference is ( lambda ), is Kunits. Find out the intensity of light at a point where path difference is ( lambda / 3 ) |
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255 | In Youngs double slit experiment, the fringes are displaced by a distance ( x ) when a glass plate of one refractive index 1.5 is introduced in the path of one of the beams. When this plate in replaced by another plate of the same thickness, the shift of fringes is ( (3 / 2) x ) The refractive index of the second plate is A . 1.75 в. 1.50 c. 1.25 D. 1.00 |
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256 | Soap bubble looks coloured due to A. dispersion B. reflection c. interference D. None of these |
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257 | According to the principle of complementarity, phenomena can have contradictory properties. These properties cannot be explained simultaneously. Identify phenomenon that are examples of complementarity. A. Mass and weight B. Heat and temperature c. Light waves and particles D. Magnetic and electric fields E. Frequency and intensity of sound |
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258 | Write down four differences between interference and diffraction: |
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259 | In Young’s double slit experiment, if monochromatic light used is replaced by white light then : A. no fringes are observed B. only central fringe is white, all other fringes are coloured c. all bright fringes become white. D. all bright fringes have colour between violet and red |
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260 | The diffraction effect can be observed in A. only sound waves B. only light waves C. only ultrasonic waves D. sound as well as light waves |
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261 | 9. In a single slit diffraction experiment first minimum for red light (660 nm) coincides with first maximum of some other wavelength 2. The value of l’is (a) 4400 Å (b) 6600 Å (c) 2000 Å (d) 3500 Å |
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262 | What is thickness of the plate? ( A .5 mu m ) В. ( 0.005 mu m ) ( mathrm{c} .7 mu mathrm{m} ) D. ( 0.007 mu m ) |
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263 | The amplitudes of two interfering waves are ( 4 mathrm{cm} ) and ( 3 mathrm{cm} ) respectively. If the resultant amplitude is ( 1 mathrm{cm} ) then the interference becomes A. constructive B. Destructive c. Both constructive and destructive D. given data is insufficient |
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264 | In a Young’s Double Slit experiment, films of thickness ( t_{A} ) and ( t_{B} ) and refractive indices ( mu_{A} ) and ( mu_{B} ) are placed in front of slits ( A ) and ( B ) respectively. If ( boldsymbol{mu}_{A} boldsymbol{t}_{A}=boldsymbol{mu}_{B} boldsymbol{t}_{B}, ) then the central maxima ( operatorname{may} ) This question has multiple correct options A. not shift B. shift forwards A c. shift towards B D. None of these |
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265 | Both light and sound waves produce diffraction. It is more difficult to observe the diffraction with light waves because: A. light wave do not require medium B. wavelength of light waves is far smaller c. light waves are transverse D. speed of light is far greater |
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266 | 9. Two beams of light having intensities I and 41 interfere to produce a fringe pattern on a screen. The phase between the beams is tu2 at point A and n at point B. Then, the difference between the resultant intensities at A and B is (a) 21 (b) 41 (c) 51 (d) 71 |
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267 | toppr Q Type your que microscope is the product of the lateral magnification ( m_{1} ) of the objective and the angular magnification ( M_{2} ) of the eyepiece. The former is given by ( boldsymbol{m}_{1}=frac{boldsymbol{S}_{1}^{prime}}{boldsymbol{S}_{1}} ) Where ( S_{1} ) and ( S_{1}^{prime} ) are the object and image distance for the objective lens. Ordinarily the object is very close to the focus, resulting in an image whose distance from the objective is much larger than the focal length ( f_{1} ). Thus ( S_{1} ) is approximately equal to ( f_{1} ) and ( m_{1}= ) ( -frac{S_{1}^{prime}}{boldsymbol{f}_{1}}, ) approximately. The angular magnification of the eyepiece from ( M=-frac{u^{prime}}{u}=frac{y / f}{y / 25}=frac{25}{f} ) centimeters) is ( M_{2}=25 mathrm{cm} / mathrm{f}_{2}, ) Where ( f_{2} ) is the focal length of the eyepiece, considered as a simple lens. Hence the overall magnification M of the compound microscope is, apart from a negative sign, which is customarily ignored, ( M=m_{1} M_{2}=frac{(25 c m) S_{1}^{prime}}{f} ) 1. What is the resolving power of the instrument whose magnifying power is given in the passage? A ( cdot frac{mu sin theta}{0.61 lambda} ) в. ( frac{mu sin theta}{1.22 lambda} ) c. ( frac{mu sin theta}{lambda} ) D. ( frac{sin theta}{1.22 lambda} ) |
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268 | Two plane wavefronts of light, one incident on a thin convex lens and another on the refracting face of a thin prism. After refraction at them, the emerging wavefronts respectively become A. plane wavefront and plane wavefront B. plane wavefront and spherical wavefront c. spherical wavefront and plane wavefront D. spherical wavefront and spherical wavefront E . elliptical wavefront and spherical wavefront |
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269 | The device which produces highly coherent sources is A. Fresnel biprism B. Young’s double sitt c. Laser D. Lloyd’s mirror |
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270 | Unpolarised light of intensity ( 32 W m^{-2} ) passes through three polarizers such that transmission axis of first is crossed with third. If intensity of emerging light is ( 2 W m^{-2} ), what is the angle of transmission axis between the first two polarisers? ( A cdot 30 ) B . 45 ( c cdot 22.5 ) D. ( 60^{circ} ) |
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271 | 7. In a YDSE bichromatic lights of wavelengths 400 nm and 560 nm are used. The distance between the slits is 0.1 mm and the distance between the plane of the slits and the screen is 1 m. The minimum distance between two successive regions of complete darkness is (a) 4 mm (b) 5.6 mm (c) 14 mm (d) 28 mm |
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272 | ( ln ) YDSE, ( d=2 m m, D=2 m ) and ( lambda= ) ( 500 n m . ) If intensities of two slits are ( I_{0} ) and ( 9 I_{0}, ) then find intensity at ( y= ) ( frac{1}{6} m m ) A ( cdot 7 I_{0} ) в. ( 10 I_{0} ) ( c cdot 16 I_{0} ) D. ( 4 I_{0} ) |
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273 | 35. A double-slit experiment is immersed in a liquid of refractive index 1.33. It has slit separation of 1 mm and distance between the plane of slits and screen is 1.33 m. The slits are illuminated by a parallel beam of light whose wavelength in air is 6830 Å. Then the fringe width is (a) 6.3 x 104 m m (b) 8.3 x 104 m (c) 6.3 x 10-2 m (d) 6.3 x 10 m |
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274 | In YDSE, find the missing wavelength at ( boldsymbol{y}=boldsymbol{d}, ) where symbols have their usual meaning (take ( D>>d ) ). ( ^{mathrm{A}} cdot frac{d^{2}}{D} ) B. ( frac{2 d^{2}}{7 D} ) c. ( frac{3 d^{2}}{D} ) D. ( frac{d^{2}}{3 D} ) |
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275 | The wave fronts of light wave traveling in vacuum are given by ( boldsymbol{x}+boldsymbol{y}+boldsymbol{z}=boldsymbol{c} ) The angle made by the light ray with the X-axis is: A ( cdot 0^{circ} ) B . ( 45^{circ} ) ( c cdot 90^{circ} ) D. ( cos ^{-1} frac{1}{sqrt{3}} ) |
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276 | 11. White light may be considered to be a mixture of waves with 2 ranging between 3900 Å and 7800 A. An oil film of thickness 10000 Å is examined normally by reflected light. If u = 1.4, then the film appears bright for (a) 4308 Å, 5091 A, 6222 Å (b) 4000 Å, 5091 Å, 5600 Å (c) 4667 Å, 6222 Å, 7000 Å (d) 4000 Å, 4667 Å, 5600 Å, 7000 Å |
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277 | A red flower when viewed through blue light appears: A . red B. blue c. black D. violet |
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278 | 55. A beam of natural light falls on a system of 6 polaroids, which are arranged in succession such that each polaroid is turned through 30′ with respect to the preceding one. The percentage of incident intensity that passes through the system will be (a) 100% (b) 50% (c) 30% (d) 12% |
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279 | Two Polaroids ( P_{1} ) and ( P_{2} ) are placed with their axis perpendicular to each other. Unpolarized light ( l_{0} ) is incident on ( P_{1} . A ) third polaroid ( P_{3} ) is kept in between ( P_{1} ) and ( P_{2} ) such that its axis makes an angle ( 45^{circ} ) with that of ( P_{1} . ) The intensity of transmitted light through ( P_{2} ) is A ( cdot frac{I_{0}}{2} ) B. ( frac{I_{0}}{4} ) ( c cdot frac{I_{0}}{8} ) D. ( frac{1}{16} ) |
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280 | A: In interference pattern, intensity of successive fringes due to achromatic light is not same. R: In interference, only redistribution of energy takes place. A. Both A and R are true, and R is correct explanation of B. Both A and R are true, and R is not correct explanation of A c. A is true but R is false D. A is false but R is true |
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281 | The intensity at the maximum in a Young’s double slit experiment is ( boldsymbol{I}_{0} ) Distance between two slits is ( boldsymbol{d}=mathbf{5} boldsymbol{lambda} ) where ( lambda ) is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance ( D= ) ( 10 d ? ) ( mathbf{A} cdot I_{0} ) в. ( frac{I_{0}}{4} ) c. ( frac{3}{4} I_{0} ) D. ( frac{I_{0}}{2} ) |
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282 | A plane wavefront ( A_{1} B_{1} ) is incident at a boundary ( A_{1} B_{2} ) as shown. It takes time ( tau ) for the wavefront to travel from ( B_{1} ) to ( B_{2} . ) Speeds of propagation of light in medium 1 and 2 are ( v_{1} ) and ( v_{2} ) respectively and ( v_{2}>v_{1} . ) For the total internal reflection of wavefront. ( mathbf{A} cdot v_{1} tau>A_{1} B_{2} ) B . ( v_{2} tau>A_{1} B_{2} ) c. ( v_{1} tau<A_{1} B_{2} ) D. ( v_{2} tau<A_{1} B_{2} ) |
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283 | State whether true or false: During constructive interference, the crest of one wave meets the crest of the other wave or the trough of one wave meets the trough of the other wave. A. True B. False |
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284 | the central bright maxima is twice as wide as the other maxima. | 12 |

285 | A source ( S ) and a detector ( D ) of high frequency waves are a distance d apart on the ground. The direct wave from S is found to be in phase at D with the wave from ( S ) that is reflected rays make the same angle with the reflecting layer. When the layer rises a distance ( h, ) no signal is detected at D. Neglect absorption in the atmosphere and find the relation between ( mathrm{d}, mathrm{h}, mathrm{H} ) and the wavelength ( lambda ) of the waves. |
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286 | Use Huygen’s principle to show how a plane wavelength propagates from a denser to rarer medium. Hence verify Snell’s law of refraction |
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287 | Two small loud speakers ( A ) and ( B ) are driven by the same amplifier as shown in Fig and emit pure sinusoidal waves in phase. Speaker ( A ) is ( 1 mathrm{m} ) away as shown and speaker ( B ) is 2 m away from the amplifier. The microphone is ( 4 mathrm{m} ) away from the amplifier in transverse direction as indicated in the Figure. For what frequencies constructive interference will occur at ( boldsymbol{P} ) (microphone point) B. 500 Нz, 1500 нz c. 550 Нz, 1100 Н ( z_{text {… }} ) D. 500 нz, 1000 Нz,1500 нz |
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288 | 3. Light waves travel in vacuum along the y-axis. Which of the following may represent the wavefront? (a) x = constant (b) y = constant (c) z= constant (d) x + y + z = constant |
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289 | From Brewster’s law, it follows that the angle of polarization depends upon A. the wavelength of light B. orientation of the plane of polarization c. orientation of the plane of vibration D. none of these |
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290 | The two lenses of an achromatic doublet should have: A. Equal powers B. Equal dispersive powers C. Equal ratio of their power and dispersive power D. Sum of the product of their powers and dispersive power equal to zero |
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291 | A convex lens of diameter ( 8 mathrm{cm} ) is used to focus a parallel beam of light of wavelength ( 620 n m . ) Light is focused at a distance ( 20 c m, ) from the lens. What would be the radius of central bright fringe? |
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292 | Unpolarised light is passed through a polaroid ( P_{1} . ) When this polarised beam passes through another polaroid ( P_{2} ) and if the pass axis of ( boldsymbol{P}_{2} ) makes angle ( boldsymbol{theta} ) with the pass axis of ( P_{1} ), then write the expression of intensity for the polarised beam passing through ( P_{2} . ) Draw a plot showing the variation of intensity when ( theta ) varies from 0 to ( 2 pi ) |
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293 | A single slit of width ( a ) is illuminated by violet light of wave length 400 nm and width of the diffraction pattern is measured as ( y ). Half of the slit is covered and illuminated with 600 nm. The width of the diffraction pattern will be A ( cdot frac{y}{3} ) B. pattern vanishes and width is zero c. ( 3 y ) D. none of these |
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294 | 42. Angular width (B) of central maximum of a diffraction pattern on a single slit does not depend upon (a) distance between slit and screen (b) wavelength of light used (c) width of the slit (d) frequency of light used |
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295 | What is a wavefront? How does it propagate ? Using Huygens’ principle, explain reflection of a plane wavefront from a surface and verify the laws of reflection. |
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296 | In Youngs double slit experiment, the slits are ( 2 m m ) apart and are ¡IIluminated with a mixture of two wavelengths ( lambda=12000 A^{circ} ) and ( lambda= ) ( 10000 A^{circ} . ) At what minimum distance from the common central bright fringe on a screen ( 2 m ) from the slits will a bright fringe from one interference coincide with a bright fringe from the other? A. ( 3.2 mathrm{mm} ) B. ( 6.0 mathrm{mm} ) c. ( 7.2 mathrm{mm} ) D. ( 9.2 mathrm{mm} ) |
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297 | A plane polarized light is incident normally on a tourmaline plate. Its ( overrightarrow{boldsymbol{E}} ) vectors make an angle of ( 60^{circ} ) with the optic axis of the plate. Find the percentage difference between initial and final intensities. A . ( 25 % ) B . 50% c. ( 75 % ) D. 90% |
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298 | If in an unpolarised light ( mathrm{E}=2 vec{i}+3 vec{j} ) and ( vec{H}=3 vec{i}-2 vec{j}, ) then the direction of propagation is given by A ( -13 vec{k} ) the ( -13 vec{k} ). B . ( -13 vec{j} ) ( mathbf{c} cdot-6 vec{i}+6 vec{k} ) D. ( 5 vec{i}-4 vec{k} ) |
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299 | When unpolarized light beams are incidents in the air into glass ( (n=1.5 ) at polarising angle) A. reflected beams is 100 polarised B. reflect and refracted beams are partially polarised c. the reason for (a) is that almost all the light is reflected D. all the above |
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300 | On the basis of Huygen’s Wave theory of light, show that angle of reflection is equal to angle of incidence. You must draw a labelled diagram for this derivation. |
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301 | What is the path difference for destructive interference? A ( cdot frac{(2 n+1) lambda}{2} ) B. ( frac{(n+1) lambda}{2} ) c. ( n(lambda+1) ) D. ( n lambda ) |
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302 | A diffraction pattern is obtained by making blue light incident on a narrow slit. If blue light is replaced by red light, then the diffraction bands A. disappear B. become broader c. become narrower D. remain same |
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303 | At the polarising angle ( left(boldsymbol{theta}_{B}right), ) angle of refraction is given by : A ( .90^{circ} ) В. ( 90^{circ}+theta_{B} ) c. ( 90^{circ}-theta_{B} ) D. ( frac{90^{circ}}{theta_{B}} ) |
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304 | 11. A mixture of lights, consisting of wavelength 590 nm and an unknown wavelength illuminates Young’s double slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of the known light coincides with the fourth bright fringe of the unknown light. From this data, the wavelength of the unknown light is (a) 393.4 nm (b) 885.0 nm (c) 442.5 nm (d) 776.8 nm (AIEEE 2009) |
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305 | Assume 100 pm ( X ) -ray beam is passed through YDSE. Interference pattern is observed on a photographic plate placed ( 40 mathrm{cm} ) away from the slits. What should be the separation between the slits so that the separation between two successive maxima is ( 0.1 mathrm{mm} ) A ( .4 mu m ) в. ( 0.4 mu m ) ( c .4 n m ) D. ( 40 mu m ) |
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306 | Making a light wave vibrate in only one plane is known as: A. refraction B. reflection c. Interference D. diffraction E. polarization. |
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307 | happens when two or more waves overlap. |
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308 | The condition for destructive interference is path difference should be equal to : A. odd integral multiple of wavelength B. Integral multiple of wavelength c. odd integral multiple of half wavelength D. Integral multiple of half wavelength |
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309 | Light of wavelength ( lambda_{0} ) in air enters a medium of refractive index ( n . ) If two points ( A ) and ( B ) in this medium lid along the path of this light at a distance ( x, ) then phase difference ( phi_{0} ) between these two points is ( ^{mathbf{A}} cdot_{0}=frac{1}{n}left(frac{2 pi}{lambda_{0}}right) x ) B ( cdot_{phi_{0}}=nleft(frac{2 pi}{lambda_{0}}right) x ) ( ^{mathbf{c}} cdot_{phi_{0}}=(n-1)left(frac{2 pi}{lambda_{0}}right) x ) D ( , quad phi_{0}=frac{1}{(n-1)}left(frac{2 pi}{lambda_{0}}right) x ) |
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310 | Why are coherent sources required to create interference of light? | 12 |

311 | 23. In a Young’s double slit experiment, slits are separ by 0.5 mm, and the screen is placed 150 cm away beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is (a) 9.75 mm (b) 15.6 mm (c) 1.56 mm (d) 7.8 mm (JEE Main 2017) |
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312 | Wave front means: A. all particles in it have same phase B. few particles are in same phase, rest are in opposite phase C . all particles have opposite phase of vibrations D. all particles have random vibrations |
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313 | Using Huygen’s wave theory, derive Snell’s law of refraction. | 12 |

314 | Why does light from a clear blue portion of the sky show a rise and fall of intensity when viewed through a polaroid which is rotated? Explain by drawing the necessary diagram. | 12 |

315 | An arrangement for YDSE is shown in figure. S is a light source then find the position of central maxima from point 0 on screen B. A. ( 5 mathrm{mm} ) below B. ( 5 mathrm{mm} ) above 0 c. ( 30 mathrm{mm} ) below ( D cdot alpha ) |
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316 | If the polarizing angle of a piece of glass for green light is ( 54.74^{circ}, ) then the angle of minimum deviation for an equilateral prism made of same glass is : ( left[mathrm{GIVEN}, tan 54.74^{circ}=1.414right] ) A ( cdot 45^{circ} ) B. 54.74 ( c cdot 60 ) ( D cdot 30^{circ} ) |
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317 | In a double-slit experiment the angular width of a fringe is found to be ( 0.2^{circ} ) on a screen placed 1 m away. The wavelength of light used is ( 600 n m ) What will be the angular width of the fringe is the entire experimental apparatus is immersed in water? Take refractive index of water to be ( frac{4}{3} ) |
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318 | ASSERTION (A):Hyugens’ theory failed to explain polarization
REASON (R): According to Hyugens’ theory light is longitudinal wave |
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319 | Two superimposing waves are represented by equation ( boldsymbol{y}_{1}= ) ( 2 sin 2 pi(10 t-0.4 x) ) and ( y_{2}= ) ( 4 sin 2 pi(20 t-0.8 x) . ) The ratio of ( I_{max } ) to ( boldsymbol{I}_{m i n} ) ( mathbf{A} cdot 36: 4 ) B. 25: 9 ( c cdot 1: 4 ) D. 4: 1 |
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320 | Two coherent monochromatic light beams of intensities ( I ) and ( 4 I ) are superposed. The maximum and minimum possible resulting intensities are : A ( .5 I ) and 0 B. ( 5 I ) and ( 3 I ) c. ( 9 I ) and ( I ) D. ( 9 I ) and ( 3 I ) |
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321 | A slit of width ( a ) is illuminated by a monochromatic light of wavelength ( mathbf{6 5 0} ) nm. The value of ( a ) when the first minima falls at an angle of diffraction of ( 30^{0} ) is A. ( 1.3 times 10^{-6} m ) B . ( 2.6 times 10^{-6} m ) c. ( 3.9 times 10^{-6} mathrm{m} ) D. ( 5.2 times 10^{-6} m ) |
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322 | The condition for obtaining secondary maxima in the diffraction pattern due to single slit is (symbols have their usual meaning) ( A cdot a sin theta=n lambda ) B. ( a sin theta=(2 n-1) frac{lambda}{2} ) ( c cdot a sin theta=(2 n-1) lambda ) D. ( a sin theta=frac{n lambda}{2} ) |
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323 | The phases of the light wave at ( mathbf{c}, mathbf{d}, mathbf{e} ) and ( mathbf{f} ) are ( phi_{mathrm{c}}, phi_{mathrm{d}}, phi_{mathrm{e}} ) and ( phi_{mathrm{f}} ) respectively. It is given that ( phi_{mathrm{c}} neq phi_{mathrm{f}} ) A ( cdot phi_{mathrm{c}} ) cannot be equal to ( phi_{mathrm{d}} ) B. ( phi_{mathrm{d}} ) can be equal to ( phi_{mathrm{e}} ) C ( cdotleft(phi_{mathrm{d}}-phi_{mathrm{f}}right) ) is equal to ( left(phi_{mathrm{c}}-phi_{mathrm{e}}right) ) ( mathbf{D} cdotleft(phi_{mathrm{d}}-phi_{mathrm{c}}right) ) is not equal to ( left(phi_{mathrm{f}}-phi_{mathrm{e}}right) ) |
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324 | A parallel beam of natural light is incident at an angle of ( 58^{circ} ) on a plane glass surface. The reflected beam is completely linearly polarized(tan ( 58^{circ}= ) 1.6). The angle of refraction of the transmitted beam and the refractive index of the glass are : A ( cdot 32^{circ}, 1.6 ) B. 3.2^,1.6 c. ( 32^{circ}, 1.3 ) D. 3.2?, 1.3 |
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325 | In an interference pattern produced by two identical slits, the intensity at the site of the central maximum is I. The intensity at the same spot when either of the two slits is closed is ( I_{0} ). We must have: ( mathbf{A} cdot I=I_{0} ) в. ( I=2 I_{0} ) c. ( I=4 I_{0} ) D. ( I ) and ( I_{circ} ) are not related |
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326 | A monochromatic beam of light falls on Young’s double slit experiment apparatus as shown in figure. A thin sheet of glass is inserted .in front of lower slit ( S_{2} ) The central bright fringe can be obtained: ( A cdot A t O ) B. Above ( O ) c. Below ( O ) D. Anywhere depending on angle ( theta ), thickness of plate ( t ), and refractive index of glass ( mu ) |
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327 | 63. Light of wavelength 2 = 5890 Å falls on a double-slit arrangement having separation d=0.2 mm. Athin lens of focal length f= 1 mis placed near the slits. The linear separation of fringes on a screen placed in the focal plane of the lens is (a) 3 mm (b) 4 mm (c) 2 mm (d) 1 mm C 1 1 11 |
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328 | Two polaroids are kept crossed to each other. If one of them is rotated an angle ( 60^{circ}, ) the percentage of incident light now transmitted through the system is A . 10% B. 20% c. 25% D. 12.5% |
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329 | Two sources of light of wavelengths ( 2500 A ) and ( 3500 A ) are used in Young’s double slit experiment simultaneously. Which orders of fringes of two wavelength patterns coincide? A. 3 rd order of 1 st source and 5 th of the 2 nd B. 7th order of 1st and 5th order of 2nd c. 5 th order of 1 st and 3 rd order of 2 nd D. 5 th order of 1 st and 7 th order of 2 nd |
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330 | State the two laws of reflection of light. | 12 |

331 | In Young’s double slit experiment, distance between two slits is ( 0.28 mathrm{mm} ) and distance between slits and screen is ( 1.4 mathrm{m} ). Distance between central bright hinge and third bright fringe is ( 0.9 mathrm{cm}, ) what is the wavelength of light used? A ( .4000 A^{circ} ) в. ( 6000 A^{circ} ) c. ( 3000 A^{circ} ) D. ( 5000 A^{circ} ) |
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332 | Two coherent monochromatic light beams of intensities ( I ) and ( 4 I ) are superposed. The maximum and minimum possible intensities in the resulting beam are: A. ( 5 I ) and ( I ) B. ( 5 I ) and ( 3 I ) c. ( 9 I ) and ( I ) D. ( 9 I ) and ( 3 I ) |
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333 | A and ( mathrm{B} ) are facing the mirror and standing in such a way that ( A ) can see ( B ) and ( B ) can see A. Explain this phenomenon. |
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334 | When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is A. zero в. ( pi ) ( c cdot pi / 2 ) D. 2 ( pi ) |
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335 | A plane wave of monochromatic light falls normally on a uniformly thin film of oil which covers a glass plate. The wavelength of source constructive interference is observed for ( lambda_{1}=5000 stackrel{circ}{A} ) and ( lambda_{2}=10000 A ) and for no other wavelength in between. If ( mu ) of oil is 1.25 and that of glass is ( 1.5, ) the thickness of film will be A . 0.2 B. 0.1 ( c .0 .8 ) D. 0.4 |
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336 | Unpolarised light is passed through a polaroid ( P_{1} ).When this polarised beam passes through another polaroid ( P_{2} ) and if the pass axis of ( P_{2} ) makes angle ( theta ) with the pass axis of ( P_{1} ). then write the intensity when ( theta ) varies from 0 to ( 2 pi ) |
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337 | Name the physical quantity which remains same for microwaves ( 1 mathrm{mm} ) and UV radiation of ( 6000_{A}^{circ} ) in a vacuum |
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338 | ( lambda_{a} ) and ( lambda_{m} ) are the wavelengths of a beam of light in air and medium respectively. If ( theta ) is the polarising angle, the correct relation between ( lambda_{a}, lambda_{m} ) and ( boldsymbol{theta} ) is: A ( cdot lambda_{a}=lambda_{m} tan ^{2} theta ) B ( cdot lambda_{m}=lambda_{a} tan ^{2} theta ) ( mathbf{c} cdot lambda_{a}=lambda_{m} cot theta ) D. ( lambda_{m}=lambda_{a} cot theta ) |
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339 | Can white light produce interference? What is the nature? |
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340 | In Young’s double slit experiment the distance between two slits is ( 2 m m ) and screen is at a distance of ( 120 mathrm{cm} ) from the plane of slits. The smallest distance from the central maxima where the bright fringe due to light of wavelength ( 6500 A^{circ} ) and ( 5200 A^{circ} ) would coincide? A ( .0 .156 mathrm{cm} ) B. ( 0.186 mathrm{cm} ) c. ( 0.486 mathrm{cm} ) D. ( 0.456 mathrm{cm} ) |
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341 | If ( boldsymbol{d}=mathbf{0 . 5 m m}, boldsymbol{lambda}=mathbf{5 0 0 0} boldsymbol{A} ) and ( boldsymbol{D}= ) 100 ( c m ), find the value of ( n ) for the closest second bright ring. ( A cdot 888 ) В. 83 ( c .914 ) D. 998 |
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342 | What is meant by diffraction of light? | 12 |

343 | The interference pattern with two coherent light sources of density ratio ( n ) In the interference pattern, the ratio ( frac{boldsymbol{I}_{m a x}-boldsymbol{I}_{m i n}}{boldsymbol{I}_{m a x}+boldsymbol{I}_{m i n}} ) will be: A. ( frac{sqrt{n}}{n+1} ) B. ( frac{2 sqrt{n}}{n+1} ) c. ( frac{sqrt{n}}{(n+1)^{2}} ) D. ( frac{2 sqrt{n}}{(n+1)^{2}} ) |
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344 | 20. In Young’s double-slit experiment, the slits are illuminated by monochromatic light. The entire set-up is immersed in pure water. Which of the following act cannot restore the original fringe width? (a) Bringing the slits close together. (b) Moving the screen away from the slit plane. (c) Replacing the incident light by that of longer wavelength. (d) Introducing a thin transparent slab in front of one of the slits. |
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345 | If the frequency of the source is doubled in Young’s double slit experiment, then fringe width ( (boldsymbol{beta}) ) will be- A. unchanged B. ( beta / 2 ) ( c cdot 2 beta ) D. ( 3 beta ) |
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346 | In a Young’s double slit experiment, the path different, at a certain point on the screen, between two interfering waves is ( frac{1}{8} t h ) of wavelength. The ratio of the intensity at this point to that at the centre of a brigth fringe is close to : A .0 .94 в. 0.74 c. 0.85 D. 0.80 |
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347 | The air film in a Newton’s ring apparatus is replaced by an oil film. The radii of the rings A. remains the same B. increases c. decreases D. none of the above |
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348 | In Young’s double slit experiment shows in figure, ( S_{1} ) and ( S_{2} ) are coherent sources and ( mathrm{S} ) is the screen having a hole at a point ( 1.0 mathrm{mm} ) away from the central line. White light ( (400 text { to } 700 ) nm) is sent through the slits. Which wavelength passing through the hole has the strongest intensity? A. ( 400 mathrm{nm} ) B. 700 nm ( c .500 mathrm{nm} ) D. 667 nm |
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349 | Draw the intensity pattern for single slit diffraction and double slit interference. Hence state two differences between interference and diffraction patterns. |
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350 | In a simple slit diffraction pattern intensity and width of fringes are A. Unequal width B. Equal width c. Equal width and equal intensity D. Unequal width and unequal intensity |
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351 | In Young’s double slit experiment, separation between the slits is halved and distance between slits and screen is doubled. The fringe width is A. same B. quadrupled c. halved D. one-third |
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352 | 74. Light from a source emitting two wavelengths , and 2, is allowed to fall on Young’s double-slit apparatus after filtering one of the wavelengths. The position of interfer- ence maxima is noted. When the filter is removed both the wavelengths are incident and it is found that maximum intensity is produced where the fourth maxima occured previously. If the other wavelength is filtered, at the same location the third maxima is found. What is the ratio of wavelengths? In ma (d) (a) |
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353 | In Young’s double slit experiment, interference pattern will not be seen if one uses A. a LASER as the source of light B. two LASER sources in front of two slits c. two sodium light lamps in front of two slits D. in both (b) and (c) above |
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354 | Albert Einstein used corpuscular theory to explain: A ( . E=m c^{2} ) B. The photoelectric effect c. Quantisation of charge D. magic of light |
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355 | Two points sources separated by ( 2.0 m ) are radiating in phase with ( lambda=0.50 m ) A detector moves in a circular path around the two sources in a plane containing them. How many maxima are detected? ( A cdot 16 ) B . 20 ( c cdot 24 ) D. 32 |
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356 | Monochromatic light of wavelength ( 4500 A ) falls on slit of width ‘a’. In diffraction pattern second maxima deviates through ( 30^{circ} . ) The slit width is ( mathbf{A} cdot 900 stackrel{circ}{A} ) в. 18000 А ( mathrm{c} cdot_{13500 AA} ) D ( cdot 22500 ) 台 |
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357 | A thin film with index of refraction 1.50 coats a glass lens with index of refraction ( 1.80 . ) What is the minimum thickness of the film that will strongly reflect light with wavelength 600 nm? A . ( 150 mathrm{nm} ) B. ( 200 n m ) c. 300 nm D. ( 450 n m ) |
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358 | White light is incident normally on a soap film of thickness ( 15 times 10^{-5} mathrm{cm} ) and refractive index ( 1.33 . ) Which wavelength is reflected maximum in the visible region? A ( .26000 A^{circ} ) B. ( 8866 A^{circ} ) c. ( 5320 A^{circ} ) D. ( 3800 A^{circ} ) |
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359 | Which of the following statements is correct? A. Diffraction is because of interference of light from same sources whereas interference is due to light form two isolated sources. B. Diffraction is due to interaction of light from same wave fronts whereas interference is due to interaction of two waves derived from the same source. C. Diffraction is due to interference of waves derived from the same source whereas interference is bending of light from the same source D. Diffraction is due to reflected waves whereas interference is due to transmitted waves from a source. |
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360 | A parallel beam of light ( lambda=5000 A^{circ} ) falls normally on a single narrow slit of width ( 0.001 m m . ) The light is focused by a convex lens on a screen placed in the focal plane. The first minimum will be formed for the angle of diffraction are equal to: A . ( 0^{circ} ) В. ( 15^{circ} ) ( c cdot 30^{0} ) D. ( 50^{circ} ) |
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361 | Distinguish between the phenomenon of interference and diffraction of light. | 12 |

362 | In producing a pure spectrum, the incident light is passed through a narrow slit placed in the focal plane of an achromatic lens because a narrow slit A. produce less diffraction B. increase intensity C. allows only one colour at a time D. allows a more parallel beam when it passes through the lens. |
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363 | The intensity of the light coming from one of the slits in YDSE is double the intensity from the other slit. Find the ratio of the maximum intensity to minimum intensity in the interference fringe pattern observed ( A cdot 32 ) B. 34 ( c .36 ) D. 38 |
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364 | Q Type your question Youngs double slit apparatus. The separation between maxima is measured on a screen placed parallel to the plane of the slits at a distance of 1.0 ( m ) from it as shown in figure. The separation between the slits is ( 2 d= ) 1 ( m m ) (a) If the incident beam falls normally on the double slit apparatus, find the ( y- ) coordinates of all the interface minima of the screen (b) If the incident beam makes an angle of ( 30^{circ} ) with the ( x- ) axis (as shown in fig) find the ( y- ) coordinates of the first minima on either side of the central maximum. |
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365 | In conventional light sources: A. different atoms emit radiation at different times B. there is no phase relation between the emitted photons C. different atoms emit photon in different direction D. all of the above |
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366 | A parallel beam of diameter ( d ) is incident on air-glass interface as shown in figure. The diameter of refracted light beam is : ( left(d=3 m m, theta=45^{circ} text { and } frac{n_{g l a s s}}{n_{a i r}}=frac{3}{2}right) ) A . ( sqrt{12} ) mm B. ( sqrt{14} ) mm ( c cdot sqrt{6} m m ) D. ( 4.5 mathrm{mm} ) |
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367 | A polnt sources ( boldsymbol{s} ) emicting IIght of wavelength 600 nm is placed at a very small height ( h ) above a flat reflecting surface ( boldsymbol{A B} ) (see figure). The intensity of the reflected light is ( 36 % ) of the incident intensity. Interference fringes are observed on a screen placed parallel to the reflecting surface at a very large distance ( D ) from it.What is the shape of the interference fringes on the screen? A. Circular B. helical C . eliptical D. spiral |
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368 | In a Young’s double-slit interference experiment using a yellow light of wavelength ( lambda ), with the slits labelled ( S_{1} ) and ( S_{2} . ) If ( P ) is the centre of a dark fringe on the screen on which the resulting diffraction pattern is projected, Find out the equations relating ( S_{1} P ) and ( S_{2} P ) which could be true? A ( cdot S_{1} P-S_{2} P=frac{1}{2 lambda} ) B . ( S_{1} P-S_{2} P=lambda ) c. ( S_{1} P-S_{2} P=2 lambda ) D. ( S_{1} P-S_{2} P=3 lambda ) E . ( S_{1} P=S_{2} P ) |
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369 | Unpolarised light of intensity ( 32 mathrm{W} mathrm{m}^{-2} ) passes through three polarizes is crossed with that of the first. The intensity of final emerging light is 3 ( mathrm{W} mathrm{m}^{-2} . ) The intensity of light transmitted by first polarizer will be ( A cdot 32 W m^{-2} ) B. ( 16 mathrm{W} mathrm{m}^{-2} ) ( c cdot 8 w m^{-2} ) D. ( 4 mathrm{Wm}^{-2} ) |
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370 | Which of the following statements applies to light? A. Light can only be described as particles. B. Light can only be described as waves. C. Light can be described as rays, waves and particles. D. Light can only be described as rays. |
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371 | The angular width of the central maximum in a single slit diffraction pattern is ( 60^{circ} . ) The width of the slit is 1 ( mu mathrm{m} . ) The slit is illuminated by monochromatic plane waves. If another slit of same width is made near it, Young’s fringes can be observed on a screen placed at a distance ( 50 mathrm{cm} ) from the slits. If the observed fringe width is 1cm, what is slit separation distance? (i.e., distance between the centres of each slit.) A. ( 75 mu ) m B. ( 100 mu ) m c. ( 25 mu ) m D. ( 50 mu ) m |
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372 | A stretched string is vibrating according to the equation ( boldsymbol{y}= ) ( 5 sin left(frac{pi x}{3}right) cos 400 pi t, ) where ( y ) and a are in ( mathrm{cm} ) and ( t ) is second. Potential energy will be zero at time t:- A . 2 s B. 4 s ( c cdot 8 s ) D. 16 s |
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373 | In the adjoining figure ( A, B, ) and ( C ) represents three progressive waves. Which of the following statement about the waves is correct? A ( cdot ) wave ( mathrm{C} ) lags behind in phase by ( frac{pi}{2} ) from ( mathrm{A} ) and ( mathrm{B} ) leads by ( frac{pi}{2} ) B. Wave C leads in phase by ( pi ) from ( A ) and ( B ) lags behind by ( pi ) C. wave C leads in phase by ( frac{pi}{2} ) from A and lags behind by ( frac{pi}{2} ) D. Wave C lags behind in phase by ( pi ) from ( mathrm{A} ) and ( mathrm{B} ) leads by ( pi ) |
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374 | If ( mu_{O} ) and ( mu_{e} ) are the refractive indices of a double refracting crystal, then 1) ( mu_{O}mu_{e} ) for calacite crystal A. both 1 and 2 are true B. 1 is true 2 is false c. 1 false 2 is true D. both 1 and 2 are false |
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375 | In biprism experiment a source of wavelength ( 6500 A ) is replaced by source of wavelength ( 5500 A ). Calculate change in fringe width if the screen is at, ( 1 mathrm{m} ) distance from the slits which are 1 mm apart. |
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376 | 26. Young’s double-slit experiment is made in a liquid. The 10th bright fringe in liquid lies where 6th dark fringe lies in vacuum. The refractive index of the liquid is approximately (a) 1.8 b (b) 1.54 (c) 1.67 (d) 1.2 |
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377 | Plane polarized light is passed through a Polaroid. Now the Polaroid is given one complete rotation about the direction of light propagation. When viewed through another Polaroid (analyser), one of the following is observed: A. The intensity of light gradually decreases to zero and then remains zero B. The intensity of light becomes twice maximum and twice zero c. The intensity of light becomes maximum and stays maximum D. The intensity of light does not change |
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378 | Huygen’s concept of secondary wave A. allows us to find the focal length of a thick lens B. is a geometrical method to find a wavefront ( mathrm{C} ). is used to determine the velocity of light D. is used to explain polarization |
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379 | 12. The ratio of the intensity at the centre of a bright fringe to the intensity at a point one-quarter of the distance between two fringes from the centre is (a) 2 (b) 1/2 (c) 4 (d) 16 |
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380 | What is the Brewster angle for water? The refractive index of water with respect to air is 1.33 |
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381 | After reflection from a concave mirror, a plane wave front becomes A. Cylindrical B. Spherical c. Remains planar D. None of the above |
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382 | The ratio of maximum to minimum intensity due to superposition of two waves is ( frac{49}{9} . ) Then the ratio of the intensity of component waves is : A ( cdot frac{25}{4} ) в. ( frac{16}{25} ) c. ( frac{4}{49} ) D. ( frac{9}{49} ) |
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383 | Which of the following generates a plane wavefront? A ( . alpha- ) rays B. ( beta- ) rays c. ( gamma- ) rays D. None of these |
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384 | Huygen’s concept of wavelets is useful in A. explaining polarisation B. determining focal length of lenses c. determining chromatic aberration D. geometrical reconstruction of a wavefront |
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385 | A slit of width a is illuminated by the red light of wavelength ( 6500 A^{0} . ) If the first minimum falls at ( theta=30^{circ}, ) the value of a is A ( cdot 6.5 times 10^{-4} m m ) B. 1.3 micron c. ( 3250 A^{circ} ) D. ( 2.6 times 10^{-4} mathrm{cm} ) |
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386 | The correct relation between ( S, theta, L ) and ( C ) for an optically active solution is: ( mathbf{A} cdot S=theta L C ) B. ( theta=S L C ) ( mathbf{c} . L=theta S C ) ( mathbf{D} cdot C=theta L S ) |
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387 | Light waves travel in vaccum along the y-axis. Then the wave front is: A. ( y= ) constant B. ( x= ) constant c. ( z= ) constant D. ( x+y+z= ) constant |
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388 | State Huygen’s principle. | 12 |

389 | Assertion In YDSE, if separation between the slits is less than wavelength of light, then no interference pattern can be observed. Reason For interference pattern to be observed, light sources have to be coherent. |
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390 | 31. In Young’s double-slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, the number of fringes observed in the same segment of the screen is given by (a) 12 (b) 18 (c) 24 (d) 30 |
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391 | State whether true or false. Light is a form of energy that causes a sensation of smell. A. True B. False |
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392 | The correct statement from the following is: A. Light exhibits particle nature in propagation and wave nature in mutual interaction with matter. B. Light exhibits both wave nature and particle nature in mutual interaction with matter. C. Light exhibits both wave and particle nature in propagation. D. Light exhibits wave nature in propagation and particle nature in mutual interaction with matter |
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393 | At polarising angle, the angle between the reflected ray and refracted ray from a surface | 12 |

394 | Determine the separation between 1st and 2 nd dark fringes from the left end air cavity. A ( cdot frac{3 L}{7}+frac{2 lambda_{0}}{mu} ) B. ( frac{5 L}{7} ) c. ( frac{4 L}{7} ) D. ( frac{6 L}{7} ) |
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395 | The intensity falls as we move to successive maxima away from the centre on either side. |
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396 | Unpolarized light of intensity ( boldsymbol{I}_{0} ) is incident on surface of a block of a glass of Brewster’s angle. In that case, which one of the following statement is true? A. transmitted light is partially polarized with intensity ( I_{0} / 2 ) B. transmitted light is completely polarized with intensity less than ( I_{0} / 2 ) C . reflected light is partially polarized with intensity ( I_{0} / 2 ) D. reflected light is completely polarized with intensity less than ( I_{0} / 2 ) |
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397 | Two coherent light beams of intensity and 41 are superposed. The maximum and minimum possible intensities in the resulting beam are. A. 9| and | B. 9I and 31 c. 5 । and 1 D. 5 । and 3 । |
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398 | Name a phenomenon or an experiment which proves: (i) Particle nature of electro magnetic radiatons. (ii) Wave nature of particles. (Description of the phenomenon experiment is not required) |
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399 | With the help of an experiment, state how will you identify whether a given beam of light is polarised or unpolarised. | 12 |

400 | In above shown figure, fringe pattern is produced by a monochromatic light passing through two narrow slit. If the fringe width is ( 2 mathrm{cm} ) then, which of the following changes would increase the distance between the bands? A. Moving the slits closer together B. Making the light source brighter c. Moving the slits closer to the screen D. Increasing the frequency of the light E. shortening the wavelength of the light |
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401 | A: The corpuscular theory fails in explaining the velocities of light in air and water. B: According to corpuscular theory, the light should travel faster in a ‘denser medium than in a rarer medium. A. If both A and B are true but the B is the correct explanation of A B. If both A and B are true but the B is not the correct explanation of A c. If A is true but B is false D. If both the A and B are false E. If B is true but A is false |
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402 | A light ray is incident on a glass slab it is partially reflected and partially transmitted. Then the reflected ray is A. completely polarised and highly intense. B. partially polarised and poorly intense c. partially polarised and highly intense D. completely polarised and poorly intense. |
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403 | Which of the following properties shows that light is a transverse wave? A. Reflection B. Interference c. Diffraction D. Polarization |
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404 | The wave front is a surface in which: A. All points are in the same phase B. There is a pair of points in opposite phase C there is a pair of points with phase difference ( left(frac{pi}{2}right) ) D. There is no relation between the phase |
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405 | ( ln Y D S E, d=2 m m, D=2 m ) and ( lambda=500 n m . ) If intensity of two slits are ( l_{0} ) and ( 9 l_{0}, ) then find the intensity at ( boldsymbol{y}=frac{1}{6} boldsymbol{m m} ) A ( .7 l_{0} ) B. ( 10 l_{0} ) c. ( 16 l_{0} ) D. ( 4 l_{0} ) |
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406 | Constructive interference is the method of superimposing waves which has a phase difference of ( pi / 2 ) rads. A. True B. False |
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407 | Two waves of intensities ( I ) and ( 4 I ) produce interference. Then the intensity of constructive and destructive interferences respectively are A. ( 3 I, 5 I ) B. ( 5 I, 3 I ) c. ( I, 9 I ) D. ( 9 I, I ) |
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408 | In a double-slit experiment, instead of taking slits of equal width, one slit is made twice as wide as the other. Then in the interference pattern A. the intensities of both the maxima and the minima increase B. the intensity of the maxima increases and the minima has zero intensity c. the intensity of the maxima decreases and that of the minima increases D. the intensity of the maxima decreases and the minima has zero intensity |
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409 | 4. The maximum intensity in Young’s double slit experi is 1o. Distance between the slits is d = 52, wher the wavelength of monochromatic light used in the experiment. What will be the intensity of light in front of one of the slits on a screen at a distance D = 10 d (b) 1 (c) 10 |
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410 | The transverse nature of light waves is verified by A. reflection of light B. polarisation of light c. refraction of light D. interference of light |
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411 | A beam of light consisting of two wavelengths, ( 650 mathrm{nm} ) and ( 520 mathrm{nm} ) is used to obtain interference fringes in a Youngs double-slit experiment. What is the least distance from the central maximum where the bright fringes due to both the wavelengths coincide? A . ( 1.17 mathrm{mm} ) B. 2.52 mm c. ( 1.56 mathrm{mm} ) D. 3.14 mm |
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412 | fa minima is formed at the detector, then the magnitude of wavelength ( lambda ) of the wave produced is given by A ( .2 pi R ) в. ( frac{3}{2} pi R ) c. ( frac{5}{2} pi ) D. none of these |
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413 | Two radio frequency point sources ( S_{1} ) and ( S_{2} ), separated by distance ( 2.5 mathrm{m} ) are emitting in phase waves of wavelength ( 1 mathrm{m} . ) A detector moves in a large circular path around the two sources in a plane containing them. The number of maxima that will be detected by it over the complete circular path, are A . 16 B. 12 ( c cdot 10 ) D. 8 |
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414 | Why do polarized sun glasses block out some reflected light (glare), but do not block out light that has not been reflected? A. Some reflected light is at least partially polarizedd B. Some reflected light changes frequency c. Some reflected light is red-shifted D. Some reflected light is at least partially diffracted E. Some reflected light splits into multiple photons |
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415 | The shift of the interference pattern on the screen when the slit is displayed by ( boldsymbol{S l}=mathbf{1} boldsymbol{m} boldsymbol{m} ) along the arc of radius ( boldsymbol{r} ) with centre at 0 ( A cdot 4 m m ) B. ( 6 m m ) ( c .10 m m ) D. ( 13 m m ) |
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416 | Select the right one from the given options. A. Christian Huygens, a Contemporary of Newton established the Wave theory of light by assuming that light waves are transverse. B. Maxwell provided the compelling theoretical evidence that light is transverse in nature. C. Thomas Young experimentally proved the wave behavior of light and Huygens assumption. D. All the statements given above are correct |
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417 | If instead of ( M g F_{2}, ) the coating of the substance whose refractive indices is larger than the refractive index of glass was made then interference A. would not have occurred B. would have occurred due to total internal reflection of light c. would have occurred due to refraction of light D. would have occurred due to strong reflection |
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418 | 39. In YDSE, find the thickness of a glass slab (u=1.5) which should be placed before the upper slit S, so that the central maximum now lies at a point where 5th bright fringe was lying earlier (before inserting the slab). Wavelength of light used is 5000 Å. (a) 5 x 100 m (b) 3 x 10m (c) 10 x 10 m m (d) 5 x 10-5 m |
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419 | What is diffraction of light? A. The process where the incident light on a surface is bounced back into the same medium B. Splitting of a ray of light into its 7 constituent colours is known as diffraction C. The process by which a beam of light is spread out as a result of passing through a narrow aperture or across an edge,is known as diffraction D. None of these |
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420 | A plane wave of wavelength ( 6250 A ) is incident normally on a slit of width ( 2 times ) ( 10^{-2} mathrm{cm} . ) The width of the principle maximum of diffraction pattern on a screen at a distance of ( 50 mathrm{cm} ) will be: A ( cdot 312 times 10^{-3} mathrm{cm} ) B . ( 312.5 times 10^{-4} mathrm{cm} ) c. 312 ст D. ( 312.5 times 10^{-5} mathrm{cm} ) |
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421 | Two Nicole prisms are kept perpendicular. One of them is illuminated with a light intensity (natural) ( I_{o} ). Two more nicol prisms are introduced in between symmetrically. Find the light intensity emitted from the last nicol prism. A ( cdot frac{27 I_{0}}{64} ) в. ( frac{27 I_{o}}{128_{o}} ) c. ( _{9} frac{I_{o}}{32} ) D. ( frac{9 I_{0}}{64} ) |
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422 | 10. The ratio of intensities of consecutive maxima in the diffraction pattern due to a single slit is (a) 1:4:9 (b) 1:2:3 4 4 (c) 1: – 972 2572 (a) 1: 72 |
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423 | What is wavefront of light waves? | 12 |

424 | In a single slit diffraction experiment, the width of the slit is made half the original width A. the width of the central maxima becomes double B. the width of the central maxima becomes half c. the width of the central maxima becomes one fourth D. the width of the central maxima becomes four times |
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425 | Diffraction of sound is very easy, to observe in day-to-day life. This is not so with light. This is so because ( A cdot lambda_{S}>lambda_{L} ) в. ( lambda_{s}<lambda_{L} ) c. light waves are transverse and sound waves are longitudinal D. ( lambda_{S}=lambda_{L} ) |
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426 | Two point white dots are ( 1 mathrm{mm} ) apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye? [Take wave length of light =500 nm] A . ( 10 mathrm{m} ) B. ( 5 mathrm{m} ) ( c cdot 15 m ) D. None of these |
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427 | 48. If in single slit diffraction pattern, first minima for red light (600 nm) coincides with first maxima of some other wavelength 2, then a would be (a) 400 nm (b) 440 nm (c) 0.3 nm (d) 900 nm |
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428 | Choose the correct statements among the following given options. A. Brewster’s angle is independent of wavelength of light. B. Brewster’s angle is independent of the nature of reflecting surface. C. Brewster’s angle is different for different wavelengths. D. Brewsters angle depends on wavelength but not on the nature of reflecting surface. |
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429 | In Young’s double slit experiment, a glass plate is placed before a slit which absorbs half the intensity of light. Under this case: A. The brightness of fringes decreases B. The fringes width decrease C. No fringes will be observed D. The bright fringes become fainter and the dark fringes have finite light intensity |
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430 | Which of the following statement is false: A. Sound and light wave exhibit interference B. Sound and light wave exhibit diffraction C. Light wave exhibits polarization while sound wave does not D. Sound wave exhibits polarization while light wave does not |
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431 | In which of the following the final image is erect? A. Compound microscope B. Astronomical telescope c. simple microscope D. All of the above |
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432 | Light from two coherent sources of the same amplitude ( A ) and wavelength ( lambda ) illuminates the screen. The intensity of the central maximum is ( I_{0} . ) If the sources were incoherent, the intensity at the same point will be. A . ( 4 I_{0} ) в. ( 1 I_{0} ) c. ( I_{0} ) D. ( frac{I_{0}}{2} ) |
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433 | A very thin film in reflected white light appears A . coloured B. white c. black D. red |
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434 | Ratio of maximum to minimum ntensities at ( P ) is ( A, 2: 1 ) 3.4: 1 ( c cdot 8: 1 ) 0.16: 1 |
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435 | Find the nature and order of the interference at 0 ( A cdot 20^{t h} operatorname{minimal} ) B. ( 20^{text {th }} ) maxima ( mathrm{c} cdot 10^{t h} ) maxima ( D cdot 10^{t h} operatorname{minimaa} ) |
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436 | For a single slit of width “a”, the first minimum of the interference pattern of a monochromatic light of wavelength ( lambda ) occurs at an angle of ( frac{k}{a} . ) At the same angle of ( frac{k}{a}, ) we get a maximum for two narrow slits separated by a distance “a” Explain. |
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437 | In a Young’s double slit experiment set up, source ( S ) of wavelength ( 500 n m ) illuminates two slits ( S_{1} ) and ( S_{2} ) which act as two coherent sources. The source ( S ) oscillates about its own position according to the equation ( y=0.5 sin pi t ) where ( y ) is in ( mathrm{mm} ) and ( t ) in seconds. The minimum value of time ( t ) for which the intensity at point ( P ) on the screen exactly infront of the upper slit becomes minimum is : ( A cdot 1 s ) B. ( 2 s ) ( c .3 s ) D. ( 1.5 s ) |
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438 | Consider the arrangement shown in Fig 29.15(a). The distance ( D ) is large, compared to ( d ). Find minimum value of ( d ) so that there is a dark fringe at ( O . ) For the same value of ( d ) find ( x ) at which next bright fringes is formed. |
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439 | A beam of unpolarized light is passed first through a tourmaline crystal ( boldsymbol{A} ) and then through another tourmaline crystal ( B ) oriented so that its principal plane is parallel to that of ( A ). The intensity of final emergent light is ( I ) The value of the ( I ) is A ( cdot frac{I_{o}}{2} ) в. ( frac{I_{o}}{4} ) c. ( frac{I_{o}}{8} ) D. none of these |
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440 | The speed at which the current travels in a conductor, is nearly. A ( .3 times 10^{4} m s^{-1} ) В. ( 3 times 10^{5} mathrm{ms}^{-1} ) c. ( 4 times 10^{6} m s^{-1} ) D. ( 3 times 10^{8} mathrm{ms}^{-1} ) |
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441 | Derive the expression for the intensity at a point where interference of light occurs. Arrive at the conditions for the maximum and zero intensity. |
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442 | The first diffraction minima due to a single slit diffraction is at ( theta=30^{circ} ) for a light of wavelength 5000 A. The width of the slit is: ( mathbf{A} cdot 5 times 10^{-5} mathrm{cm} ) В. ( 10 times 10^{-5} mathrm{cm} ) c. ( 2.5 times 10^{-5} mathrm{cm} ) D. ( 1.25 times 10^{-5} mathrm{cm} ) |
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443 | In ( Y D S E, d=2 m m, D=2 m ) and ( lambda=500 ) nm. If intensity of two slits are ( l_{0} ) and ( 9 l_{0} ) then find intensity at ( boldsymbol{y}=frac{1}{6} ) A. ( 7 l_{0} ) B. ( 10 l_{0} ) c. ( 16 l_{0} ) D. ( 4 l_{0} ) |
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444 | Light is incident on a polarizer with intensity ( I_{0} . ) A second prism called analyser is kept at a angle of ( 15^{circ}, ) from the first polarizer then the intensity of final emergent light will be? |
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445 | (a) How does an unpolarized light incident on a Polaroid get polarized? Describe briefly, with the help of a necessary diagram, the polarization of light by reflection form a transparent medium. (b) Two polaroids ( ^{prime} A^{prime} ) and ( ^{prime} B^{prime} ) are kept in crossed position. How should a third Polaroid ‘ ( C^{prime} ) be placed between them so that the intensity of polarized light transmitted by Polaroid ( B ) reduces to 1/8th of the intensity of unpolarized light incident of ( boldsymbol{A} ) ? |
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446 | Which of the following does not support the wave nature of light? A . Interference B. Diffraction c. Polarisation D. Photoelectric effect. |
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447 | In a Young’s double slit experiment, let ( A ) and ( B ) be the two slits. A thin film of thickness ( t ) and refractive index ( mu ) is placed in front of ( boldsymbol{A} ). Let ( boldsymbol{beta}= ) fringe width The central maximum will shift This question has multiple correct options A. towards ( A ) B. towards ( B ) ( c cdot operatorname{byt}(mu-1) frac{beta}{lambda} ) D. by ( mu t frac{beta}{lambda} ) |
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448 | Does the principle of conservation of energy hold for interference and diffraction phenomena? Explain briefly. |
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449 | The path of the difference between two interfering the waves at a point on the screen ( frac{lambda}{8} . ) The ratio of intensity at this point and that of at the central fringe will be ( mathbf{A} cdot 0.853 ) B. 8.53 c. 85.3 D. 853 |
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450 | Consider a two slit interference arrangements such that the distance of the screen from the slits is half the distance between the slits. Obtain the value of ( mathrm{D} ) in terms of ( lambda ) such that the first minima on the screen falls at a distance D from the centre 0 ( A cdot frac{lambda}{2.472} ) в. ( frac{lambda}{2.236} ) c. ( frac{lambda}{1.227} ) D. ( frac{lambda}{3412} ) |
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451 | 15. Unpolarized light of intensity 32 Wm passes thro three polarizers such that transmission axes of the first and second polarizer makes and angle 30° with each other and the transmission axis of the last polarizer is crossed with that of the first. The intensity of final emerging light will be (a) 32 Wm-2 (b) 3 Wm-2 (c) 8 Wm-2 (d) 4 Wm-2 |
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452 | Two coherent sources ( S_{1} ) and ( S_{2} ) vibrating in phase emit light of wavelength ( lambda ). The separation between them is ( 2 lambda ) as shown in figure. The first bright fringe is formed at ( P ) due to interference on a screen placed at a distance ( D ) from ( S_{1}(D>>lambda), ) then ( O P ) is: A ( cdot sqrt{2} D ) в. ( 1.5 D ) c. ( sqrt{3} D ) D. ( D ) |
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453 | (A) : Newton’s corpuscular theory of light could not explain refraction of light. (B) : Huygen’s wave theory fails to explain polarization property of light. A. A is true B is false B. A is false B is true c. Both ( A ) and ( B ) are true D. Both A and B are false |
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454 | Destructive interference of two waves travelling in a medium occurs when the crest of one wave lines up with the of another wave A. trough B. amplitude c. crest D. frequency E. wavelength |
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455 | How could two waves on a rope interfere so that the rope did not move at all? |
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456 | Assertion In Young’s interference experiment fringes become brighter if one of the slits is covered by cellophone paper. Reason The intensity of light emerging from the slit increases and the two interfering beams have unequal intensities. A. Statement I is True and Statement 2 is True and is correct explanation of Statement 1 B. Statementl is True and Statement 2 is True but not the correct explanation of Statement t. c. statement lis False and statement 2 is False D. Statement lis True and Statement 2 is False |
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457 | In Young’s experiment, the wavelength of monochromatic light used is 6000 A. the optical path difference between the rays from the two coherent sources at point ( P ) on the screen is ( 0.0075 mathrm{mm} ) and at a point ( Q ) on the screen is ( 0.0015 mathrm{mm} ) How many bright and dark bands are observed between the two points ( P ) and Q? |
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458 | U 0.034 11 38. In a double-slit experiment, the dista double-slit experiment, the distance between the slits is d. The screen is at a distance D from the slits. If a bright fringe is formed opposite to a slit on the screen, the order of the fringe is d² 22D 22D d2 (d) 0 d (C) AND |
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459 | Identify the correct statement from the following: A. Wave nature of light was proposed by Huygens. B. The direction of light ray and its wave front are opposite. C. Huygen’s wave theory could not explain phenomenon of reflection. D. A monochromatic ray of light after passing through the prism should create a spectrum of seven colours. |
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460 | When two waves of almost equal frequency ( n_{1} ) and ( n_{2} ) are produced simultaneously, then the times interval between successive maxima is A ( cdot frac{1}{n_{1}+n_{2}} ) в. ( frac{1}{n_{1}}+frac{1}{n_{2}} ) c. ( frac{1}{n_{1}}-frac{1}{n_{2}} ) D. ( frac{1}{n_{1}-n_{2}} ) |
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461 | State any one phenomenon in which moving particles exhibit wave nature. | 12 |

462 | 60. A thin film of refractive index 1.5 and thickness 4×10-cm is illuminated by light normal to the surface. What wavelength within the visible spectrum will be intensified in the reflected beam? (a) 4800 Å (b) 5800 Å (c) 6000 Å (d) 6800 Å |
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463 | In Young’s double slit experiment, first slit has width four times the width of the second slit. The ratio of the maximum intensity to the minimum intensity in the interference fringe system is: A . 2: 1 B . 4: 1 c. 9: 1 D. 8: 1 |
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464 | 20. On a hot summer night, the refractive index of ai smallest near the ground and increases with height from the ground. When a light beam is directed horizontally the Huygen’s principle leads us to conclude that as it travels, the light beam (a) becomes narrower (b) goes horizontally without any deflection (c) bends downwards (d) bends upwards (JEE Main 2015) |
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465 | Phase difference at the central point changes by ( pi / 3 ) when a thick film having refractive index 1.5 and thickness ( 0.4 mu m ) is placed in front of upper slit of a YDSE setup. If the wavelength (in ( n m ) ) of the light used is ( 600 mathrm{k}, ) find ( mathrm{k} ) |
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466 | Which of the following cannot be polarised? A. Radio waves B. ( beta ) rays c. Infrared rays D. ( gamma ) rays |
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467 | For minima to take place between two monochromatic light waves of wavelength ( lambda ), the path difference should be A ( . n lambda ) B. ( (2 n-1) frac{lambda}{4} ) c. ( (2 n-1) frac{lambda}{2} ) D. ( (2 n-1) lambda ) |
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468 | 3 incident at an angle ( alpha=30^{circ} ) with the normal to the slit plane in Young’s double-slit experiment. Assume that the intensity due to each slit at any point on the scree is ( I_{0} . ) Point ( O ) is equidistant from ( S_{1} ) and ( S_{2} ). The distance between slits is 1 mm. Then This question has multiple correct options A. the intensity at ( O ) is ( I_{0} ) B. the intensity at ( O ) is zero C. the intensity at a point on the screen ( 1 m ) below ( O ) is ( I_{0} ) D. the intensity at a point on the screen ( 1 m ) below ( O ) is zero |
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469 | The ratio of maximum to minimum intensity due to superposition of two waves is ( frac{49}{9} . ) Then the ratio of the intensity of component waves is A ( cdot frac{25}{4} ) в. ( frac{16}{25} ) c. ( frac{4}{49} ) D. ( frac{9}{49} ) |
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470 | An astronaut is looking down on earth’s surface from a space shuttle an altitude of ( 400 mathrm{km} ) Assuming that the astronaut’s pupil diameter is ( 5 mathrm{mm} ) and the wavelength of visible light is ( 500 mathrm{nm}, ) the astronaut will be able to resolve linear objects of the size of about : A . ( 0.5 mathrm{m} ) B. 5 m ( c . ) 50m D. 500m |
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471 | In the Young’s double slit experiment two slits 0.125 mm apart are illuminated by light of wavelength ( 4500 A^{circ} . ) The screen is ( 1 m ) away from the plane of the slits. Find the separation between second bright fringes on both sides of central maxima. |
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472 | In Youngs double slit experiment using monochromatic light, the fringe pattern shifts by a certain distance on the screen when a mica sheet of ( R . l . ) and thickness 1.964 micron is introduced in the path of one of the interfering waves. The mica sheet is then removed and the distance between the slits and the screen is doubled, it is found that the distance between successive maxima (or minima) now is the same as the observed fringe shift upon the introduction of the mica sheet. Calculate the wavelength of monochromatic light used in the experiment. |
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473 | toppr ‘ОGा Q Type your question_ but represents path from each of the two slits to the third “bright fringe” formed as part of the interference pattern. In the diagram how much longer is path 1 than path ( 2 ? ) ( mathbf{A} .400 n m ) B. ( 1200 n m ) ( mathbf{c} cdot 1600 n m ) D. ( 1000 n m ) E . ( 600 n m ) |
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474 | The phenomenon of rotation of plane polarized light is called: A. Kerr effect B. Double refraction c. optical activity D. Dichroism |
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475 | A light wave is incident normally over a slit of width ( 24 times 10^{-5} mathrm{cm} . ) The angular position of second dark fringe from the central maxima is ( 30^{circ} . ) What is wavelength of light? в. 5000 月 c. ( 3000 hat{h} ) D. 1500 月 |
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476 | In Young’s double slit experiment, the ratio of maximum to minimum intensities of the fringe system is 4: 1 The amplitudes of the coherent sources are in the ratio: A . 4: 1 B. 3: 1 c. 2: 1 D. 1: 1 |
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477 | If the path difference between the slits ( S_{1} ) and ( S_{2} ) is ( lambda, ) the central fringe will have an intensity of A. 0 B . ( a^{2} ) ( c cdot 2 a^{2} ) D. ( 4 a^{2} ) |
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478 | What is polarization of light? | 12 |

479 | According to corpuscular theory, the velocity of light in the denser medium is greater than that in rarer medium. A. True B. False |
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480 | In a Young’s double slit experiment, a slab of thickness ( 1.2 mu m ) and refractive index 1.5 is placed in front of one slit and another slab of thickness t and refractive index 2.5 is placed in front of the second slit. If the position of the central fringe remains unaltered, then the thickness is A. ( 0.4 mu m ) B. ( 0.8 mu m ) c. ( 1.2 mu m ) D. ( 0.72 mu m ) |
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481 | The shape of wave front at a very large distance from source is A. Circular B. Spherical c. cylindrical D. Plane |
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482 | 43. A plane wavefront (a = 6x 10-7m) falls on a slit 0.4 mm wide. A convex lens of focal length 0.8 m placed behind the slit focusses the light on a screen. What is the linear diameter of second maximum? (a) 6 mm (b) 12 mm (c) 3 mm (d) 9 mm |
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483 | Determine the distance of 4 th dark fringe from the left end of air cavity A ( cdot frac{2 L}{6}+lambda_{0} ) B. ( _{L_{1}+} frac{3 L}{4} ) ( c cdot frac{4 L}{7} ) D. ( frac{5 L}{7} ) |
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484 | Distance of ( 5^{t h} ) dark fringe from centres is 4 mm. If ( D=2 m, lambda=600 n m, ) then distance between slits is A. ( 1.35 mathrm{mm} ) B . ( 2.00 mathrm{mm} ) c. ( 3.25 mathrm{mm} ) D. ( 10.35 mathrm{mm} ) |
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485 | In a Young’s double slit experiment, let ( beta ) is the fringe width, and let ( I_{o} ) be the intensity at the central bright fringe. At a distance ( x ) from the central bright fringe, the intensity will be: A ( cdot I_{o} cos left(frac{x}{beta}right) ) B ( cdot I_{o} cos ^{2}left(frac{x}{beta}right) ) ( mathbf{c} cdot_{I_{o} cos ^{2}left(frac{pi x}{beta}right)} ) D. ( left(frac{I_{o}}{4}right) cos ^{2}left(frac{pi x}{beta}right) ) |
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486 | Two beams, ( A ) and ( B ), of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of Polaroid through ( 30^{circ} ) makes the two beams appear equally bright. If the initial intensities of the two beams are ( boldsymbol{I}_{A} ) and ( boldsymbol{I}_{B} ) respectively, then ( boldsymbol{I}_{boldsymbol{A}} / boldsymbol{I}_{boldsymbol{B}} ) equals: A . ( I ) B. ( I / 3 ) ( c cdot 3 ) D. ( 3 / 2 ) |
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487 | Write any two applications of interference | 12 |

488 | The distance between two consecutive bright bands in a bi-prism experiment is ( 0.32 mathrm{mm} ) When the red light of wavelength 6400 A is used. by how much will this distance change if the light is substituted by the blue light of wavelength 4800 A with the same setting? |
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489 | A wave is associated with matter when it is: A. stationary B. in motion with a velocity C. in motion with velocity of light D. in motion with velocity greater than that of light |
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490 | A broad source of light ( (1=680 mathrm{nm}) ) illuminates normally two glass plates ( 120 mathrm{mm} ) long that touch at end and are separated by a wire ( 0.048 mathrm{mm} ) in diameter at the other end. The total number of bright fringes that appear over the ( 120 mathrm{mm} ) distance is: A . 50 B. 100 ( c cdot 141 ) D. 400 |
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491 | State two conditions for sustained interference of light. Also write the expression for the fringe width |
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492 | Light of wavelength 500 nm goes through a pinhole of ( 0.2 m m ) and falls on a wall at a distance of ( 2 m ). What is the radius of the central bright spot formed on the wall? A ( .2 .37 mathrm{cm} ) в. 1.37 ст ( c .3 .37 mathrm{cm} ) D. ( 7.37 mathrm{cm} ) |
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493 | When light falls on matter, it can produce : A. mechanical effect B. chemical effect c. heating effect D. all the above |
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494 | Derive an expression for the bandwidth of interference fringes in Young’s double slit experiment. |
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495 | The diameter of an objective of a telescope, which can just resolve two stars situated at an angular displacement of ( 10^{-4} ) degree, should be ( left(lambda=5000 A^{0}right) ) A. 35 mm B. 35 cm ( c cdot 35 m ) D. None of the above |
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496 | In the adjacent, ( C P ) represents a wavefront and ( A O & B P, ) the corresponding two rays. Find the condition on ( theta ) for constructive interference at ( boldsymbol{P} ) between the ray ( boldsymbol{B P} ) and reflected ray ( boldsymbol{O P} ) ( A cdot cos theta=3 lambda / 2 d ) B. ( cos theta=lambda / 4 d ) ( mathbf{c} cdot sec theta-cos theta=lambda d ) ( mathbf{D} cdot sec theta-cos theta=4 lambda d ) |
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497 | Choose the correct option about light. A. Light requires a material medium to travel from one place to another B. Light does not require a material medium to propagate c. Light has mass but it is negligible D. Light waves are longitudinal wave |
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498 | Two sound speakers are driven in phase by an audio amplifier at frequency ( 600 H z . ) The speed of sound is ( 340 m / s ) The speakers are on the ( y ) -axis, one at ( boldsymbol{y}=+1.0 boldsymbol{m} ) and the other at ( boldsymbol{y}= ) ( -1.0 m . ) A listener begins at ( y=0 ) and walks along a line parallel to the ( y ) -axis at a very large distance ( x ) away. At what angle ( theta^{o} ) (between the line from the origin to the listener at the ( x ) -axis will she first hear a minimum sound intensity? |
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499 | An unpolarized beam of intensity ( 2 a^{2} ) passes through a thin Polaroid. Assuming zero absorption in the Polaroid, the intensity of emergent planes polarized light will be ( mathbf{A} cdot 2 a^{2} ) в. ( a^{2} ) ( c cdot sqrt{2} a ) D. ( frac{a^{2}}{sqrt{2}} ) |
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500 | In Young’s double slit experiment, the fringe width is ( beta . ) If the entire arrangement is placed in a liquid of refractive index ( mu, ) the fringe width will become A. ( mu beta ) в. ( frac{beta}{mu} ) ( c cdot frac{beta}{mu+1} ) D. ( frac{beta}{mu-1} ) |
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501 | Law of conservation of energy is satisfied because A. equal loss and gain in intensity is observed B. all bright fringes are equally bright C. all dark fringes are of zero brightness D. the average intensity on screen is equal to the sum of intensities of the two sources. |
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502 | A long horizontal slit is place 1 mm above a horizontal plane mirror. The interference between the light coming directly from the slit and that after reflection is seen on a screen 1 m away from the slit. If the mirror reflects only ( 64 % ) of the light falling on it, the ratio of the maximum to the minimum intensity in the interference pattern observed on the screen is: ( mathbf{A} cdot 8: 1 ) B . 3: 1 c. 81: 1 D. 9: 1 |
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503 | 73. Figure shows two coherent sources S, and S, emittin wavelength 2. The separation S, S2 = 1.52 and S, is ahe in phase by Td/2 relative to S2. Then the maxima occur in direction given by sin of (i) O (ii) 1/2 (iii) -176 (iv) -5/6 si Correct options are (a) (ii), (iii), and (iv) S. (b) (i), (ii), and (iii) (c) (i), (iii), and (iv) (d) All the above |
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504 | A beam of unpolarized light is passed first through a tourmaline crystal ( boldsymbol{A} ) and then through another tourmaline crystal ( B ) oriented so that its principal plane is parallel to that of ( A ). The intensity of final emergent light is ( I ). If ( A ) is rotated by ( 45^{0} ) on a plane, perpendicular to the direction of incident ray, then intensity of emergent light will be A ( cdot frac{I}{8} ) в. ( frac{I}{4} ) c. ( frac{I}{2} ) D. none of these |
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505 | Mark the CORRECT statements(s) This question has multiple correct options A. Direction of wave propagation is along the normal to wavefront. B. For a point source of light, the shape of wavefront can be considered to be plane at very large distance from the source. C. A point source of light is placed at the focus of a thin spherical lens, then the shape of the wavefront for emerged light may be plane. D. The shape of the wavefront for the light incident on a thin spherical lens (kept in vacuum) is plane, the shape of the wavefront corresponding to emergent light would be always spherical |
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506 | In case of theory of light nature of light match the following: List – I List – II a) Light is a collection of e) Newton’s theory photons b) Light is a form of f) Huygen’s theory electromagnetic wave g) Maxwell’s c) Light is a wave d) Light is a stream of h) Max planck’s corpuscles theory ( mathbf{A} cdot mathrm{a}-mathrm{h} ; mathrm{b}-mathrm{g} ; mathrm{c}-mathrm{f} ; mathrm{d}-mathrm{e} ) B. ( a-e ; b-f ; c-g ; d-h ) C. ( a-g ; b-h ; c-g ; d-f ) D. ( a-h ; b-g ; c-e ; d-f ) |
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507 | In Young’s double-slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to ( 400 n m, ) number of fringes observed in the same segment of the screen is given by A . 12 B . 18 ( c cdot 24 ) D. 30 |
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508 | The class of diffraction in which the incident and diffracted wave fronts are spherical is called A. Fraunhofer diffraction B. Fresnel diffraction c. Huygens’ diffraction D. Newton’s diffraction |
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509 | A source of electrons or neutrons can be located at ( S ). The beam is defined by slits ( S_{1} ) and ( S_{2} . ) The particles pass through two plates ( P_{1} ) and ( P_{2} ) such that the first plate is at zero potential and the second plate can be given any high potential. For using matter waves in a microscope of high resolution which of the following combination must be chosen? A. Electron beam with high accelerating potential B. Electron beam with low accelerating potential c. Neutron beam with high accelerating potential D. Neutron beam with low accelerating potential |
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510 | Assertion In YDSE, if a film is introduced in front of the upper slit, then the fringe pattern shifts in the downward direction Reason In YDSE if the slit widths are unequal, the minima will be completely dark A. Both Assertion and Reason are incorrect 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 correct |
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511 | A CD(Compact disc ) is read from the bottom by a semiconductor laser with wavelength ( 700 n m ) passes through a plastic substrate of refractive index 1.8 When the beam encounters 0 pit, part of the beam is reflected from the pit and part from the flat region. These two beams interfere with each other. What must be the minimum depth of the pit, So that part of the beam reflected from the pit and part reflected from the flat surface cancel out? (This cancellation allows the player to recognize beginning and end of a pit) A. ( 0.197 mu m ) B. ( 0.395 mu m ) ( c .0 .22 mu m ) D. ( 0.11 mu ) m |
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512 | A circular beam of light of diameter ( d=2 c m ) falls on a plane surface of glass. The angle of incident is ( 60^{circ} ) and refractive index of glass is ( mu=3 / 2 . ) The diameter of the refracted beam is A ( .2 .00 mathrm{cm} ) в. ( 1.50 mathrm{cm} ) c. ( 1.63 mathrm{cm} ) D. ( 2.52 mathrm{cm} ) |
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513 | A plane wavefront of wavelength ( lambda ) is incident on a single slit of width a. The angular width of principal maximum is? ( A cdot frac{lambda}{a} ) в. ( frac{2 lambda}{a} ) ( c cdot frac{a}{lambda} ) D. ( frac{a}{2 lambda} ) |
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514 | When a compact disc is illuminated by small source of white light, coloured bands are observed. This is due to A. dispersion B. diffraction c. interference D. reflection |
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515 | Find the nature and order of the interference at the point ( P ) A ( cdot 70^{t h} ) maxima B. ( 80^{text {th }} ) minima ( mathbf{c} cdot 60^{t h} operatorname{maxima} ) ( D cdot 70^{t h} operatorname{minima} ) |
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516 | In Young’s double slit experiment, the interference pattern obtained with white light will be A. the central fringe bright and alternate bright and dark fringes B. the central fringe achromatic and coloured fringes for small path difference c. the central fringe dark D. the central fringe coloured |
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517 | Two slits in Young’s experiment have widths in the ratio ( 1: 25 . ) The ratio of intensity at the maxima and minima in the interference pattern, ( frac{boldsymbol{I}_{max }}{boldsymbol{I}_{min }} ) is A ( cdot frac{4}{9} ) B. ( frac{9}{4} ) c. ( frac{121}{49} ) D. ( frac{49}{121} ) |
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518 | Two cohorent monochromatic light beams of intensities ( 4 mid ) and 9 I interfere in a Young’s double slit experimental setup to produce a fringe pattern on the screen. The phase difference between the beams at two points ( P ) and ( Q ) on the screen are ( pi / 2 ) and ( pi / 3 ) respectively. Then the ratio of the two intensities ( boldsymbol{I}_{boldsymbol{P}} / boldsymbol{I}_{Q} ) is A. 0 в. ( frac{6}{19} ) c. ( frac{13}{19} ) D. ( frac{6}{13} ) |
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519 | A narrow tube is bent in the form of a circle of radius ( R, ) as shown in the figure. Two small holes ( S ) and ( D ) are made in the tube at the positions right angle to each other. A source placed at S generated a wave of intensity ( l_{0} ) which is equally divided into two parts : One part travels along the longer path, while the other travels along the shorter path. Both the part waves meet at the point ( D ) where a detector is placed. The maximum value of ( lambda ) to produce a maxima at D is given by : A ( . pi R ) В. ( 2 pi R ) c. ( frac{pi R}{2} ) D. ( frac{3 pi R}{2} ) |
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520 | Light travels in a ( _{-}-_{-}-_{-}-_{-}- ) path A . rectilinear B. zig zagg c. circular D. helical |
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521 | A very thin film in reflected white light appears A . coloured B. white c. black D. red |
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522 | toppr Q Type your question does this affect the size and intensity of the central diffraction band? (b) In what way is diffraction from each slit related to the interference pattern in a double-slit experiment? (c) When a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why? (d) Two students are separated by a ( 7 mathrm{m} ) partition wall in a room ( 10 mathrm{m} ) high. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily. (e) Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification? |
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523 | What is wavefront? Explain laws of refraction of light on the bases of Huygens wave theory. |
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524 | Human eye: A. can detect polarized light B. cannot detect polarization of light C. can detect only circularly polarized light D. can detect only linearly polarized light |
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525 | A: Coloured spectrum is seen when we look through a cloth R: Diffraction of light takes place when light is travelling through the pores of cloth A. Both A and R are true, and R is not correct explanation of A B. Both A and R are true, and R is correct explanation of A C. A is true but R is false D. A is false but R is true |
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526 | Which of the following phenomena can be used to analyse a beam of light into its component wavelength? A . Reflection B. Refraction c. Polarisation D. Interference |
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527 | 3. In Young’s double slit experiment, the intensity on the screen at a point where path difference is 2 is K. What will be the intensity at the point where path difference is N14? K K (a) 7 (b) 5 (c) K (d) Zero |
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528 | n identical waves each of intensity ( 1_{0} ) interfere with each other. The ratio of maximum intensities if the interference is (i) coherent and (ii) incoherent is: ( mathbf{A} cdot n^{2} ) B. c. ( frac{1}{n^{2}} ) D. |
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529 | (a) Define wave-front. Use Huygen’s principle to verify the laws of refraction. (b) How is linearly polarised light obtained by the process of scattering of light? Find the Brewster angle for airglass interface, when the refractive index of glass ( =1.5 ) |
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530 | Two waves are travelling and superimposed as a result of this constructive interference occur between waves, the two waves amplitude are: A. added to produce a larger amplitude B. subtracted to produce a smaller amplitude. C . added to produce a smaller amplitude. D. cancelled out by each other E. in opposite directions. |
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531 | Sound waves from a tuning fork A reach a point ( P ) by two separate paths ABP and ACP.When ACP is greater than ABP by ( 11.5 mathrm{cm}, ) there is silence at P. When the difference is ( 23 mathrm{cm} ) the sound becomes loudest at ( P ) and when ( 34.5 mathrm{cm} ) there is silence again and so on. Calculate the minimum frequency (in Hz) of the fork if the velocity of sound is taken to be 331.2 ( mathrm{m} / mathrm{s} ) |
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532 | The maximum number of possible interference maxima for slit separation equal to twice the wavelength in Young’s double slit experiment is : A . infinite B. five c. three D. zero |
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533 | Who proposed the wave theory of light? | 12 |

534 | According to Huygens principle, during refraction of light from air to a denser medium A. Wavelength and speed increase B. Wavelength decreases but speed increases c. wavelength and speed decrease D. Wavelength increases but speed decreases |
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535 | Explain Malus law for polaroids. | 12 |

536 | A horizontal beam of vertically polarized light of intensity ( 43 mathrm{w} / mathrm{m}^{2} ) is sent through two polarizing sheets. The polarizing direction of the first is ( 60^{0} ) to the vertical, and that of the second is horizontal. The intensity of the light transmitted by the pair of sheets is (nearly) A. ( 8.1 mathrm{W} / mathrm{m}^{2} ) B. 7.3 ( mathrm{W} / mathrm{m}^{2} ) c. ( 6.4 mathrm{w} / mathrm{m}^{2} ) D. 3.8 ( mathrm{W} / mathrm{m}^{2} ) |
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537 | State Brewster’s Law. The polarising angle of a transparent medium is ( 60^{circ} . ) Find the refractive index and the angle of refraction ( left(tan 60^{circ}=right. ) ( sqrt{3}) ) |
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538 | Two nearby objects are just resolved, if the principle maximum in the diffraction pattern of one coincides with A. principal maxima of other B. first minimum of the other c. half-way between principal maximum and first ( operatorname{minimum} ) D. second maximum of the other |
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539 | What are Fraunhofer lines?? | 12 |

540 | Optically active substances are those which A. produce polarized light B. rotate the plane of polarization of the polarized light. c. produce double refraction D. convert a plane polarized light into circularly polarized light |
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541 | Light of wavelength 589.3 nm is incident normally on a slit of width ( 0 . ) ( mathrm{mm} . ) The angular width of the central diffraction maximum at a distance of Im from the slit is A ( cdot 0.68 ) В. ( 0.34^{circ} ) ( c .2 .05 ) D. None of these |
12 |

542 | The intensity at the central maximum (0) in a Yong’s double slit experimental set-up shown in the figure is ( I_{O} ). If the distance ( O P ) equals one-third of the fringe width of the pattern. show that the intensity at point P.would equal ( frac{I_{O}}{4} ) |
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543 | Two coherent sources of equal intensities produce a maximum of 100 units. If the amplitude of one of the sources is reduced by ( 20 % ), then the maximum intensity produced will be: A . 100 B. 81 c. 89 D. 60 |
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544 | 21. Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25 cm, the minimum separation between two objects that human eye can resolve at 500 nm wavelength is (a) 1 um (b) 30 um (c) 100 um (d) 300 um (JEE Main 2015) 1 |
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545 | Which of the following is the path difference for destructive interference? A. ( n(lambda+1) ) B. ( (2 n+1) frac{lambda}{2} ) c. ( n lambda ) D. ( (n+1) frac{lambda}{2} ) |
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546 | The polarising angle for a medium is found to be ( 60^{circ} . ) The critical angle of the medium is A ( cdot sin ^{-1}left(frac{1}{2}right) ) B. ( sin ^{-1}left(frac{sqrt{3}}{2}right) ) ( ^{c} cdot sin ^{-1}left(frac{1}{sqrt{3}}right) ) D. ( sin ^{-1}left(frac{1}{4}right) ) E ( cdot sin ^{-1}left(frac{2}{sqrt{3}}right) ) |
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547 | A: The corpuscular theory fails in explaining the velocities of light in air and water. B: According to corpuscular theory, the light should travel faster in a ‘denser medium than in a rarer medium. A. If both A and B are true but the B is the correct explanation of A B. If both A and B are true but the B is not the correct explanation of A c. If A is true but B is false D. If both the A and B are false E. If B is true but A is false |
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548 | If the source of light used in a Young’s double slit experiment is changed from red to violet A. the fringes will become brighter B. consecutive fringes will come closer c. the intensity of minima will increase D. the central bright fringe will become a dark fringe |
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549 | Two loudspeakers are emitting sound waves of wavelength ( mu ) with an initial phase difference of ( frac{pi}{2} . ) At what minimum distance from 0 on line AB will one hear a maxima? A ( .25 lambda ) B. ( frac{100 lambda}{sqrt{15}} ) ( c cdot frac{25 lambda}{3} ) D. ( 50 lambda ) |
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550 | The condition for observing Fraunhoffer diffraction from a single slit is that the light wavefront incident on the slit should be A. spherical B. cylindrical c. plane D. elliptical |
12 |

551 | The velocity of central maxima at ( t=5 s ) ( mathbf{i} mathbf{S} ) A ( .50 m s^{-1} ) along Y-axis B. ( 50 m s^{-1} ) along negative Y-axis ( mathrm{c} cdot 3 times 10^{8} mathrm{m} mathrm{s}^{-1} ) along ( mathrm{Y} ) -axis D. ( 3 times 10^{8} mathrm{m} mathrm{s}^{-1} ) along negative Y-axis |
12 |

552 | De Broglie theorized that all moving objects emit waves (matter waves) based on their momentum ( left(frac{boldsymbol{h}}{boldsymbol{m v}}right) ) Accordingly, as your team’s defensive end, it is your job to stop the other team’s 250 pound fullback. If you could hear the fullback’s matter waves and you listened as the opposing fullback received the ball and accelerated toward you, what sound would you hear? A. An increase in loudness and an increase in frequency B. An increase in loudness and a decrease in frequency c. A decreasing loudness and an increasing frequency D. A decreasing loudness and a decreasing frequency E. Just a loud thump! thump! thump! |
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553 | Fresnel diffraction is produced due to light rays falling on a small obstacle. The intensity of light at a point on a screen beyond an obstacle depends on: A. the focal length of lens used for observation B. the number of half-period zones that superpose at the point c. the square of the sum of the number of half period zones D. the thickness of the obstacle |
12 |

554 | The ratio of slit widths in Young’s double slit experiment is ( 4: 9 . ) The ratio of maximum and minimum intensities will be A. 169: 25 B. 81: 16 c. 13: 5 D. 25: 1 |
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555 | In Young’s interference experiment, the central bright fringe can be identified due to the fact that it A. has greater intensity than other fringes which are bright B. is wider than the other bright fringes c. is narrower than the other bright fringes D. can be obtained by using white light instead of monochromatic light |
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556 | toppr Q Type your question B. ( mathbf{C} ) ( D ) |
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557 | A: Fresnel diffraction occurs when the source of light or the screen or both are at a finite distance from the diffracting device B: Diffracted light can be used to estimate the helical structure of nuclic acids A. A is true, B is false B. Both A and B are true c. A is false, B is true D. Both A and B are false |
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558 | An unpolarized beam of light is incidents on a group of four polarizing sheets, which are arranged in such a way, that of the characteristic direction of each polarizing sheet makes an angle of ( 30^{0} ) with that of the preceding sheet. The percentage of incident light transmitted by the first polarizered will be : ( mathbf{A} cdot 100 % ) B. ( 50 % ) c. ( 25 % ) D. ( 12.5 % ) |
12 |

559 | A beam of unpolarised light passes through a tourmaline crystal ( A ) and then through another such crystal ( B ) oriented so that the principal plane is parallel to ( A ). The intensity of emergent light is ( I . ) If ( A ) now rotated by ( 45^{circ} ) in a plane perpendicular to direction of the incident ray. The emergent light will have intensity. A ( cdot frac{I}{2} ) B. ( frac{I}{sqrt{2}} ) c. ( I ) D. ( frac{I}{4} ) |
12 |

560 | State Brewster’s law. Find Brewster’s angle for a transparent liquid having refractive index 1.5 |
12 |

561 | 5. The angle of incidence at which reflected light is totally polarized for reflection from air to glass (refraction index n) is (a) sin(n) (b) sin (c) tan- (d) tan-‘(n) (AIEEE 2004) |
12 |

562 | Light waves exhibit polarization but sound waves do not exhibit polarization because they are not: A. longitudinal B. coherent c. dispersive D. transverse E. refractive |
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563 | Initially interference is observed with the entire experimental set up inside a chamber filled with air, Now the chamber is evacuated. With the same source of light used, a careful observer will find that. A. The interference pattern is almost absent as it is very much diffused B. There is no change in the interference pattern c. The fringe width is slightly decreased D. The fringe width is slightly increased |
12 |

564 | A soap film of thickness ( t ) is surrounded by air and is illuminated at near normal incidence by monochromatic light with wavelength ( lambda ) in the film. With respect to the wavelength of the monochromatic light in the film, what film thickness will produce maximum constructive interference? A ( cdot frac{1}{4} lambda ) B. ( frac{1}{2} lambda ) c. ( 1 lambda ) D. ( 2 lambda ) |
12 |

565 | A thin film with index of refraction 1.33 coats a glass lens with index of refraction ( 1.50 . ) Which of the following choices is the smallest film thickness that will not reflect light with wavelength ( 640 n m ? ) A . ( 160 n m ) B. ( 240 n m ) ( c .360 n m ) D. ( 480 n m ) |
12 |

566 | A slit of width a is illuminated by white light. The first minimum for red light ( (lambda=6500 A) ) will fall at ( theta=30 ) when a will be: A ( cdot 3200 ) В. ( 6.5 times 10^{-4} mathrm{mm} ) c. 1.3 micron D. ( 2.6 times 10^{-4} mathrm{cm} ) |
12 |

567 | In the Young’s double slit experiment two light beams of wavelengths ( lambda= ) ( 6000 A^{circ} ) and ( lambda=4800 A^{circ} ) are used. The distance between two slits is ( 2.5 m m ) The distance between slits and the screen is ( 1.5 m . ) The distance between the central maxima obtained with two beams will be A . zero B. ( 1.872 m m ) c. ( 2.872 m m ) D. ( 2.652 m m ) |
12 |

568 | The shape of the interference fringes, on the screen is A . circle B. ellipse c. parabola D. straight line |
12 |

569 | After reflection from a concave mirror, a plane wavefront becomes A. Cylindrical B. Spherical c. Remains planar D. None of the above |
12 |

570 | Critical angle for certain medium is ( sin ^{-1}(0.6) . ) The polarizing angle of that medium is : A ( cdot tan ^{-1}(1.5) ) В ( cdot tan ^{-1}(0.8) ) c. ( tan ^{-1}(1.6667) ) D. ( tan ^{-1}(0.667) ) |
12 |

571 | In double slit experiment, fringes are obtained using light of wavelength ( 4800 A^{circ} . ) One slit is covered with a thin glass film of refractive index 1.4 and another slit is covered by a film of same thickness but refractive index ( 1.7 . ) By doing so, the central fringe is shifted to fifth bright fringe in the original pattern The thickness of glass film is : A ( cdot 2 times 10^{-3} m m ) B. ( 4 times 10^{-3} mathrm{mm} ) c. ( 6 times 10^{-3} m m ) D. ( 8 times 10^{-3} mathrm{mm} ) |
12 |

572 | Light is a form of that we can detect with our A. energy, ears B. corpuscles, eyes c. energy, eyes D. sensation, skin |
12 |

573 | To increase the magnification of a telescope A. the objective lens should be of large focal length and eyepiece should be of small focal length. B. the objective and eyepiece both should be of large focal length. C. both the objective and eyepiece should be of smaller focal lengths D. the objective should be of small focal length and eyepiece should be of large focal length |
12 |

574 | A beam of unpolarised light having flux ( 10^{-3} ) watt falls normally on a polarizer of cross sectional area ( 3 times 10^{-4} m^{2} ) The polarizer rotates with an angular frequency of 31.4 rad/s. The energy of light passing through the polarizer per revolution will be: ( mathbf{A} cdot 10^{-4} ) joule B . ( 10^{-3} ) joule C ( cdot 10^{-2} ) joule D. ( 10^{-1} ) joule |
12 |

575 | State Huygen’s principle. | 12 |

576 | In YDSE, a white light is formed fringe pattern on the screen. Calculate the path difference of the light waves from the two slits at the center of the first bright fringe above the central maximum. A. 0 в. ( frac{1}{4} lambda ) ( c cdot frac{1}{2} lambda ) D. ( lambda ) E ( cdot frac{3}{2} lambda ) |
12 |

577 | A double slit interference experiment is set up in a chamber that can be completely evacuated with monochromatic light, an interference pattern is observed when the container is open to the air. As the container is evacuated, a careful observer will not that the interference fringes A. don’t change at all B. move slightly farther apart C. move slightly closer together D. disappear completely |
12 |

578 | The Young’s double slit experiment is done in a medium of refractive index 4/3. A light of 600 nm wavelength is falling on the slits have ( 0.45 mathrm{mm} ) separation. The lower slit ( S_{2} ) is covered by a thin glass sheet of thickness 10.4 mm and refractive index 1.5. The interference pattern is observed on a screen placed at ( 1.5 mathrm{m} ) from the slits as shown in the fig. (All wavelength in this problem are for the given medium of refractive index 4/3. Ignore dispersion.) Find the location of central maxima (bring fringe with zero path difference ) on the y-axis. |
12 |

579 | Who first proposed that light was wavelike in character? A. Huygens B. Newton c. Young D. Maxwell |
12 |

580 | Let ( S_{1} ) and ( S_{2} ) be the two slits in Young’s double-slit experiment. If central maxima is observed at ( boldsymbol{P} ) and angle ( angle S_{1} P S_{2}=theta, ) then the fringe width for the light of wavelength ( lambda ) will be (assume ( theta ) to be a small angle) ( A cdot lambda / theta ) в. ( lambda theta ) c. ( 2 lambda / theta ) D. ( lambda / 2 theta ) |
12 |

581 | Light of wavelength 520 mm passing through a double slit, produces interference pattern of relative intensity versus angular position ( theta ) as shown in the figure. Find the separation between the slits. |
12 |

582 | A wave or a pulse is reflected normally from the surface of a denser medium back into the rarer medium. The phase change caused by the reflection- A . B . ( pi / 2 ) ( c ) D. ( 3 pi / 2 ) |
12 |

583 | A sound wave of wavelength ( 32 mathrm{cm} ) enters the tube as shown in the figure. Then the smallest radius ( r ) so that a maximum of sound is heard at detector is : ( A cdot 7 mathrm{cm} ) в. 14 ст ( c cdot 21 c m ) D. 28 ст |
12 |

584 | A transparent medium of the angle of polarisation is ( 60^{circ} . ) Find the angle of refraction. |
12 |

585 | If the source is now changed to green light of wavelength ( 10^{-7} m ) and a new glass plate is placed in place of the previous glass plate, the central fringe shifts to a position initially occupied by the sixth bright fringe due to red light without the glass plate. What is refractive index of new glass plate? A ( .2 .6 mu m ) в. ( 1.6 mu m ) c. ( 1.2 mu m ) D. ( 2.2 mu m ) |
12 |

586 | Interference is produced with two coherent sources of the same intensity If one of the sources is covered with a thin film so as to reduce the intensity of light coming out of it to half, then: A. bright fringes will be less bright and dark fringes will be less dark B. bright fringes will be more bright and the dark fringes will be more dark c. brightness of both types of the fringes will remain the same D. dark region will spread completely |
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587 | Photoelectric effect supports the quantum nature of light because This question has multiple correct options A. There is minimum frequency of light below which no photoelectrons are emitted B. The maximum KE of photoelectrons depends only on the frequency of light and not on its intensity C. Even when the metal surface is faintly illuminated by light of wavelength less than the threshold wavelength, the photoelectrons leave the surface immediately D. Electric charge of photoelectrons is quantized |
12 |

588 | Assertion: A white source of light during interference forms only white and black fringes. Reason: Width of fringe is inversely proportional to the wavelength of the light used. A. If both assertion and reason are true but the reason is the correct explanation of assertion B. If both assertion and reason are true but the reason is not the correct explanation of assertion c. If assertion is true but reason is false D. If both the assertion and reason are false E. If reason is true but assertion is false |
12 |

589 | In YDSE, the source is placed symmetrical to the slits. If a transparent slab is placed in front of the upper slit, then(slab can absorb a fraction of light) This question has multiple correct options |
12 |

590 | Draw and explain the process of formation of image with a pinhole camera? |
12 |

591 | Consider a film of thickness ( L ) as shown in four different cases below. Notice the observation of film with perpendicularly falling light. Mark the correct statement(s). (Take ( L=1.5 lambda) ) This question has multiple correct options A. For (1) and (2), the reflection at film interfaces causes zero phase difference for two reflected rays B. For 92 ) and (3), the reflection at film interfaces causes phase difference of ( pi ) for two reflected rays C. For (1) , the film will appear dark, if it is observed through reflected rays from film interfaces D. For (3), the film will appear dark, if it is observed through reflected rays from film interfaces |
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592 | Diffraction gratings provide much brighter interference pattern since more light passes through them compared with double slits. A . True B. False |
12 |

593 | The intensity of principal maxima in the single slit diffraction pattern is ( I_{o} ) ? What will be the intensity when slit width is doubled? A ( .2 I_{0} ) в. ( 4 I_{0} ) c. ( I_{o} ) D. ( frac{I_{0}}{2} ) |
12 |

594 | 40. A slit of width a is illuminated by white light. For red light (a = 6500 Å), the first minima is obtained at O=30°. Then the value of a will be (a) 3250 Å (b) 6.5 x 10-4 mm (c) 1.24 microns (d) 2.6 x 104 cm |
12 |

595 | The sensor is exposed for ( 0.1 s ) to a ( 200 W ) lamp ( 10 m ) away. The sensor has opening that is 20 mm in a diameter How many photons enter the sensor if the wavelength of light is 600 mm? (assume that all the energy of the lamp is given off as light). A . ( 1.53 times 10^{11} ) B. ( 1.53 times 10^{2} ) c. ( 1.53 times 10^{4} ) D. ( 1.53 times 10^{13} ) |
12 |

596 | At ( t=0, ) fringe width is ( beta_{1}, ) and ( a t t= ) ( 2 s, ) fringe width of figure is ( beta_{2} . ) Then ( A cdot beta_{1}>beta_{2} ) в. ( beta_{2}>beta_{1} ) c. ( beta_{1}=beta_{2} ) D. data is insufficient |
12 |

597 | Which of the following is a unit for intensity of light? A. candle power B. Lux c. Both A & B D. None of the above |
12 |

598 | The angular spread of central maximum, in the diffraction pattern, does not depend on A. the distance between the slit and sources B. width of slitt c. wavelength of light D. frequency of light |
12 |

599 | If ( z=frac{lambda D}{4 d} ) A ( cdot[3-2 sqrt{2}]^{2} ) B ( cdot[3+sqrt{2}]^{2} ) c. ( [3-sqrt{2}]^{2} ) D ( cdot[3+2 sqrt{2}]^{2} ) |
12 |

600 | Ekectron microscope is based on the principle A. Photoelectric effect B. Wave nature of electron c. superconductivity D. Laws of electromagnetic induction |
12 |

601 | In Lloyd’s single mirror method we have A. Both sources virtual B. One source virtual and one real c. Both sources real D. None of these |
12 |

602 | 25. Unpolarized light of intensity I passes through an ideal polarizer A. Another identical polarizer B is placed behind A. The intensity of light beyond B is found to be 1/2. Now another identical polarizer C is placed between A and B. The intensity beyond B is now found to be I/8. The angle between polarizer A and C is (a) 60° (b) 0° (c) 30° (d) 45° (JEE Main 2018) |
12 |

603 | 16. In a YDSE with identical slits, the intensity of the central bright fringe is 1o. If one of the slits is covered, the intensity at the same point is (a) 21. (b) lo (C) 1/2 (d) 10/4 |
12 |

604 | The path difference between two monochromatic light waves of wavelength ( 4000 A ) is ( 2 times 10^{-7} m . ) The phase difference between them is A . ( pi ) B. ( 2 pi ) c. ( frac{3 pi}{2} ) D. |
12 |

605 | The shape of the wave diverging from a point of source is | 12 |

606 | In Young’s double slit experiment, when wavelength used is ( 6000 A ) and the screen is ( 40 mathrm{cm} ) from the slits, the fringes ( 0.012 mathrm{cm} ) wide. What is the distance between the slits? A ( .0 .24 mathrm{cm} ) B. ( 0.2 mathrm{cm} ) ( mathrm{c} cdot 2.4 mathrm{cm} ) D. ( 0.024 mathrm{cm} ) |
12 |

607 | Electrons accelerated from rest by an electrostatic potential are collimated and sent through a Young’s double slit setup. The figure width is w. If the accelerating potential is doubled then the width is now close to. ( mathbf{A} cdot 0.5 mathrm{w} ) в. 0.7 w c. ( 1.0 mathrm{w} ) D. 2.0 w |
12 |

608 | What does the term point to correspondence in the paragraph refer to? A. Waves having constant amplitude B. Waves having constant phase relation c. Waves having same frequency D. Wave having same amplitude,frequency and constant phase relation |
12 |

609 | A: Radio wave can diffract at the edges of buildings B: X-rays can diffract at the interiors of a crystal A. A is true, B is false B. Both A and B are true c. A is false, B is true D. Both A and B are false |
12 |

610 | 57. Blue light of wavelength 480 nm is most strongly reflected off a thin film of oil on a glass slab when viewed near normal incidence. Assuming that the index of refraction of the oil is 1.2 and that of the glass is 1.6, what is the minimum thickness of the oil film (other than zero)? (a) 100 nm (b) 200 nm (c) 300 nm (d) none |
12 |

611 | 34. In Young’s double-slit experiment, the intensity of light at a point on the screen, where the path difference is 2, is I. The intensity of light at a point where the path difference becomes N3 is (a) I (b) (d) I |
12 |

612 | Two coherent light sources whose intensity ratio is 81: 1 produce interference fringes. If the ratio of intensities of maxima and minima in the fringe system is x:y. Find ( x-y ? ) |
12 |

613 | State whether True or False: The shape of the wave front originating from a line is spherical A. True B. False |
12 |

614 | Which of these waves can be polarised? A. Sound waves B. Longitudinal waves on a string C. Transverse waves on a string D. Light waves |
12 |

615 | Two speakers A and B are placed 1 ( mathrm{m} ) apart, each produces sound waves of frequency ( 1800 mathrm{Hz} ) in phase. ( mathbf{A} ) detector moving parallel to the line joining the speakers at a distance of 2.4 ( m ) away detects a maximum intensity at 0 and then at ( P . ) Speed of the sound wave is: ( A cdot 330 mathrm{ms}^{-1} ) B. 360 ( mathrm{ms}^{-1} ) c. ( 350 mathrm{ms}^{-1} ) D. ( 340 mathrm{ms}^{-1} ) |
12 |

616 | The optical instrument which is used in every cricket match is.: A. simple microscope B. Compound microscope c. Astronomical telescope D. Binocular |
12 |

617 | In Young’s double slit experiment, one of the slit is wider than another, so that amplitude of the light from one slit is double of that from other slit. If ( boldsymbol{I}_{m} ) be the maximum intensity, the resultant intensity I when they interfere at phase difference ( phi ) is given by A ( cdot frac{I_{m}}{9}(4+5 cos phi) ) в. ( frac{I_{m}}{3}left(1+2 cos ^{2} frac{phi}{2}right) ) c. ( frac{I_{m}}{5}left(1+4 cos ^{2} frac{phi}{2}right) ) D. ( frac{I_{m}}{9}left(1+8 cos ^{2} frac{phi}{2}right) ) |
12 |

618 | Photoelectric effect supports the quantum nature of light because This question has multiple correct options A. There is minimum frequency of light below which no photoelectrons are emitted B. The maximum KE of photoelectrons depends only on the frequency of light and not on its intensity C. Even when the metal surface is faintly illuminated by light of wavelength less than the threshold wavelength, the photoelectrons leave the surface immediately D. Electric charge of photoelectrons is quantized |
12 |

619 | When a drop of oil is spread on a water surface, it displays beautiful colors in daylight because of A. dispersion of light B. reflection of light c. polarization of light D. interference of light |
12 |

620 | A string of length 0.4 m and mass ( 10^{-2} k g ) is tightly clamped at its ends. The tension in the string is ( 1.6 N ) Identical wave pulses are produced at one end at equal intervals of time ( Delta t ) The value of ( Delta t ) which allows constructive interference between successive pulses is A . ( 0.05 s ) B. ( 0.10 s ) c. ( 0.20 s ) D. ( 0.40 s ) |
12 |

621 | The source is at some distance from an obstacle. Distance between obstacle and the point of observation is ( b ) and wavelength of light is ( lambda ). The distance of ( boldsymbol{n}^{t h} ) Fresnel Zone from the point of observation is : A ( cdot frac{b n lambda}{2} ) в. ( _{b-} frac{n lambda}{2} ) c. ( _{b+frac{n lambda}{2}} ) D. ( b-n lambda ) |
12 |

622 | Diffraction of light was discovered by : A. Young B. Hertz c. Grimaldi D. Malus |
12 |

623 | In Young’s double slit experiment, the source ( S ) and two slits ( A ) and ( B ) are lying in a horizontal plane. The slit ( boldsymbol{A} ) is above slit ( B ). The fringe are obtained on a vertical screen ( K . ) The optical path from ( S ) to ( B ) is increased by putting a transparent material of higher refractive indices. The path from ( boldsymbol{S} ) to ( boldsymbol{A} ) remains unchanged. As a result of this, the result fringe pattern moves some what A. upwards B. downwards c. towards left horizontally D. towards right horizontally |
12 |

624 | The angle of incidence at which reflected light is totally polarized for reflection from air to glass (refractive index ( n ) ), is: ( A cdot sin ^{-1} ) B. ( sin ^{-1}(1 / mathrm{n}) ) ( c cdot tan ^{-1}(1 / mathrm{n}) ) D. ( tan ^{-1}(n) ) |
12 |

625 | 3. To demonstrate the phenomenon of interference, we require two sources which emit radiation (a) of the same frequency and having a definite phase relationship (b) of nearly the same frequency (c) of the same frequency (d) of different wavelengths (AIEEE 2003) |
12 |

626 | If ( A ) is the amplitude of the component waves, the resultant amplitude of two waves that interfere to produce destructive interference is ( A cdot 2 A ) B. A ( c cdot 0 ) D. – – |
12 |

627 | If ( i ) is the angle of incidence, the angle between the incident wave front and the normal to the reflecting surface is ( mathbf{A} cdot i ) B. ( 90^{circ}-i ) ( mathbf{c} cdot 90^{circ}+i ) D . ( i-90^{circ} ) |
12 |

628 | In YDSE ratio of width of slit is 4: 1 then ratio of maximum to minimum intensity ( mathbf{A} cdot mathbf{9} ) B . 27 ( c .3 ) D. 81 |
12 |

629 | A narrow monochromatic beam of light intensity I is incident on a glass plate. another identical glass plate is kept close to the first one and parallel to it Each glass plate reflects ( 25 % ) of the light incident on it and transmit the remaining. find the ratio of the minimum and maximum intensity in the interference pattern formed by the two beams obtained after 1 reflection at each plate. ( mathbf{A} cdot 1: 49 ) B. 49: 1 c. 1: 23 D. 23: 1 |
12 |

630 | The reflected and refracted rays are observed to be perpendicular to each other, when ray of light is incident at an angle of ( 60^{circ} ) on a transparent block. The refractive index of that block is: ( A cdot frac{3}{2} ) B. ( frac{1}{2} ) c. ( frac{2}{sqrt{3}} ) D. ( sqrt{3} ) |
12 |

631 | The objective lens of an optical instrument is an achromat combination with a focal length of ( 90 mathrm{cm} . ) The two lenses possess dispersive powers 0.024 and 0.036 respectively and are in contact with each other. Then their focal lengths are: A. ( -30 mathrm{cm}, 45 mathrm{cm} ) в. ( 45 mathrm{cm}, 30 mathrm{cm} ) c. ( 30 mathrm{cm},-45 mathrm{cm} ) D. 30 ( c m,-30 mathrm{cm} ) |
12 |

632 | A plane polarized light is incident on a polariser with its pass axis making angle ( theta ) with ( x ) -axis, as shown in the figure. At four different values of ( boldsymbol{theta}, boldsymbol{theta}= ) ( 8^{circ}, 38^{circ}, 188^{circ} ) and ( 218^{circ}, ) the observed intensities are same. What is the angle between the direction of polarization and ( x ) -axis ( mathbf{A} cdot 203^{circ} ) В. ( 45^{circ} ) ( c cdot 98^{circ} ) ( D cdot 128^{circ} ) |
12 |

633 | Constructive and destructive interference occur in: A. cosmic rays B. light raus c. sound waves D. water waves E. All of these |
12 |

634 | In young’s double-slit experiment using mono chromatic light of wavelength ( mathbf{A} ) the intensity of light at a point on the screen where path difference is ( lambda ) is ( K ) units. What is the intensity if light at a point where path difference is ( lambda / 3 ? ) |
12 |

635 | 26 Light is incident at an angle o with the normal to a plane containing two slits of separation d. Select the expression that correctly describes the positions of the interference maxima in terms of the incoming angle and outgoing angle no (a) sin 0 + sin = C 12 m += (b) d sin 0 = ma (c) sin – sin = (m + 1) (d) sin 0+ sin = m |
12 |

636 | Four light waves are represented by ( (i) y=a_{1} sin omega t ) ( (i i) y= ) ( a_{2} sin (omega t+varepsilon) ) ( (i i i) y=a_{1} sin 2 omega t quad(i v) y= ) ( boldsymbol{a}_{2} sin 2(boldsymbol{omega} boldsymbol{t}+boldsymbol{varepsilon}) ) Interference fringes may be observed due to superposition of This question has multiple correct options A ( cdot(i) ) and ( (i i) ) B. ( ( i ) ) and (iii) c. ( ( i i ) ) and ( (i v) ) D. (iii) and (iv) |
12 |

637 | Write definitions of plane of vibration and plane of polarization. Explain the working process to obtain plane polarized light by Nicole Prism. Draw necessary diagram. | 12 |

638 | The maximum intensity produced by two coherent waves of intensity ( boldsymbol{I}_{1} ) and ( boldsymbol{I}_{2} ) will be A ( cdot I_{1}+I_{2} ) В ( cdot I_{1}^{2}+I_{2}^{2} ) ( mathbf{c} cdot I_{1}+I_{2}+2 sqrt{I_{1} I_{2}} ) D. zero |
12 |

639 | Determine the difference ( L_{1}-L_{2}(= ) ( Delta L) ) in terms of ( lambda_{0} ) A ( frac{4 lambda_{0}}{mu} ) в. ( frac{7 lambda_{0}}{2 mu} ) ( c cdot frac{3 lambda_{0}}{mu} ) D. none of the above |
12 |

640 | The velocity of light in air is ( 3 times ) ( 10^{8} m s^{-1} ) and that in water is ( 2.2 times ) ( 10^{8} m s^{-1} . ) The polarising angle of incidence is: A . 45 B. ( 50^{circ} ) c. ( 53.74^{circ} ) D. ( 63^{circ} ) |
12 |

641 | In Fresnel’s biprism expt., a mica sheet of refractive index 1.5 and thickness ( 6 x ) ( 10^{-6} mathrm{m} ) is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through 5 fringe widths. The wavelength of light used is A ( cdot 6000 stackrel{circ}{A} ) в. ( 8000 stackrel{circ}{A} ) c. 4000 , D. ( 2000 stackrel{circ}{A} ) |
12 |

642 | State Brewster’s law of polarization of light. |
12 |

643 | In Fraunhoffer diffraction experiment, is the distance between screen and the obstacle, b is the size of obstacle and ( lambda ) is wavelength of incident light. The general condition for the applicability of Fraunhoffer diffraction is: ( ^{mathbf{A} cdot} cdot frac{b^{2}}{l lambda}>>1 ) B. ( frac{b^{2}}{l lambda}=1 ) c. ( frac{b^{2}}{l lambda}<<1 ) D. ( frac{b^{2}}{l lambda} neq 1 ) |
12 |

644 | The maximum number of possible interference maxima, for slit separation equal to twice the wavelength,in Young’s double slit experiment is : A . infinite B. five c. three D. zero |
12 |

645 | JUU o 15. In the adjacent diagram, CP represents a wavefront and AO and BP, the corresponding two rays. Find the condition on for constructive interference at P between the ray BP and reflected ray OP (a) cos O = 32d (c) seco – cos 0 = Nd A/ (b) cos O = N4d (d) seco – cos 0 = 4Nd |
12 |

646 | 47. In a Fresnel’s diffraction arrangement, the screen is at a distance of 2 meter from a circular aperture. It is found that for light of wavelengths 2, and 12, the radius of 4th zone for 2, coincides with the radius of 5th zone for Then the ratio 1:1, is (a) 74/5 (b) 1574 (c) 5/4 (d) 4/5 |
12 |

647 | If two sources have a randomly varying phase difference ( varphi(t) ) the resultant intensity will be given by A. ( I_{0} ) в. ( frac{I_{0}}{2} ) c. ( 2 I_{0} ) D. ( frac{I_{0}}{sqrt{2}} ) |
12 |

648 | In the diffraction pattern due to a single slit of width ‘ ( d ) with incident light of wavelength ‘ ( lambda^{prime}, ) at an angle of diffraction ‘ ( boldsymbol{theta}^{prime} ), the condition for first minimum is ( mathbf{A} cdot lambda sin theta=d ) B. ( d cos theta=lambda ) ( mathbf{c} cdot d sin theta=lambda ) ( mathbf{D} cdot lambda cos theta=d ) |
12 |

649 | One of the two slits in YDSE is painted over, so that it transmits only light waves having intensity half of the intensity of the light waves having half of the intensity of the light waves through the other slit. As a result of this A. fringe pattern disappears B. bright fringes become brighten and dark ones become darker c. dark and bright fringes get fainter D. dark fringes get brighter and bright fringes get darker |
12 |

650 | In Young’s double slit experiment the two slits are illuminated by light of wavelength ( 5890^{circ} mathrm{A} ) and the distance between the fringes obtained on the screen is ( 0.2^{circ} . ) If the whole apparatus is immersed in water then the angular fringe width will be (refractive index of water is ( 4 / 3 ) ): A .0 .30 then 0.0 .030 в. ( 0.15^{circ} ) ( c cdot 15 ) D. ( 30^{circ} ) |
12 |

651 | Among the Fresnel zones the operative zones contributing intensity are : A. last zones B. first few zones c. middle zones D. all the zones |
12 |

652 | Light transmitted by nicol prism is A. unpolarised B. plane polarised c. circular polarised D. elliptically polarised |
12 |

653 | Two polaroids ( A ) and ( B ) are kept with their transmission axis at an angle ( theta ) with respect to one another. If the transmitted intensity of light is ( boldsymbol{I}_{t}= ) ( 0.75 I_{0}, ) where ( I_{0} ) is the intensity of light incident on the system, then ( theta ) is: A ( cdot 30^{circ} ) B . ( 45^{circ} ) ( c cdot 60^{circ} ) D. ( 90^{circ} ) |
12 |

654 | A parallel beam of monochromatic unpolarised light is incident on a transparent dielectric plate of refractive index ( frac{1}{sqrt{3}} . ) The reflected beam is completely polarised. Then the angle of incidence is ( A cdot 30^{circ} ) B. ( 60^{circ} ) ( c cdot 45^{circ} ) D. ( 75^{circ} ) |
12 |

655 | 51. Two Nicols are oriented with their principal planes making an angle of 60°. The percentage of incident unpolarized light which passes through the system is (a) 50% (b) 100% (c) 12.5% (d) 37.5% |
12 |

656 | Which vector, electric or magnetic, is used to represent the polarisation of e.m. waves? How will you show that light waves are transverse in nature?? |
12 |

657 | In the phenomena of diffraction of light, when blue light is used in the experiment in spite of red light, then A. fringes will become narrower B. fringes will become broader c. no change in fringe width D. None of these |
12 |

658 | A ray of light is incident on a thin film. As shown in the figure, ( M ) and ( N ) are two reflected rays while ( P ) and ( Q ) are two transmitted rays. Rays ( N ) and ( Q ) undergo a phase change of ( pi ). correct ordering of the refracting indices is A ( cdot n_{2}>n_{3}>n_{1} ) в. ( n_{3}>n_{2}>n_{1} ) ( mathbf{c} cdot n_{3}>n_{1}>n_{2} ) D. none of these, the specified changes cannot occu |
12 |

659 | Two coherent waves are described by the expressions ( E_{1}=E_{0} sin left(frac{2 pi x_{1}}{lambda}-2 pi f t+frac{pi}{6}right) ) ( E_{2}=E_{0} sin left(frac{2 pi x_{2}}{lambda}-2 pi f t+frac{pi}{8}right) ) Determine the relationship between ( boldsymbol{x}_{1} ) and ( x_{2} ) that produces constructive interference when the two waves are superposed |
12 |

660 | Light travels in a straight line because: A. it is not absorbed by atmosphere B. its velocity is very high c. diffraction effect is negligible D. due to interference |
12 |

661 | 66. In Young’s double-slit experiment, the first maxima is observed at a fixed point P on the screen. Now, the screen is continuously moved away from the plane of slits. The ratio of intensity at point P to the 1 intensity at point O (center of the screen) (a) remains cosntant (b) keeps on decreasing (c) first decreases and then increases (d) first decreases and then becomes constant |
12 |

662 | Which letter represents the wavelength of the light in the Young’s double slit experiment? ( A cdot A ) B. B ( c . c ) D. ( E ) |
12 |

663 | Sun light filtering through the tree leaves often makes circular patches on the ground because: A. the sun is round B. the space through which light penetrates is round c. light is transverse in nature D. of diffraction effects |
12 |

664 | Give analytical treatment of YDSE interference bands and hence obtain the expression for fringe width. |
12 |

665 | Interference fringes are obtained due to the interference of waves from two coherent sources of light with amplitudes ( a_{1} ) and ( a_{2}left(a_{1}=2 a_{2}right) . ) What is the ratio of the maximum and minimum intensities of light in the interference pattern? A .2 B. 4 ( c .9 ) D. ( infty ) |
12 |

666 | Find fringe width and number of possible maxima on the screen ( boldsymbol{E} ) A. ( 1.1 m m, 8 ) B. ( 1.1 m m, 9 ) c. ( 0.8 m m, 8 ) D. ( 0.9 m m, 9 ) |
12 |

667 | When an unpolarized light of intensity ( I_{0} ) is incident on a polarizing sheet, the intensity of the light which does not get transmitted, is : A . zero В. ( I_{0} ) c. ( frac{I_{0}}{2} ) D. ( frac{I_{0}}{4} ) |
12 |

668 | Write the definition of wavefront. | 12 |

669 | The angle between the axes of two polaroids so as to reduce the intensity of the incident unpolarised light to ( 1 / 3 ) and ( 1 / 10 ) are ( left(operatorname{given}, cos 35^{circ}=0.8192right. ) and ( left.cos 63^{circ}=0.4540right) ) A ( .35^{circ}, 63^{circ} ) в. ( 55^{circ}, 27^{circ} ) ( c cdot 63^{circ}, 35 ) D. ( 27^{circ}, 55^{circ} ) |
12 |

670 | A wave pulse traveling on a two piece string, gets partially reflected and partially transmitted at the junction. The reflected wave is inverted in shape as compared to incident one. If the incident wave has wavelength ( lambda ) and transmitted wave has ( lambda^{prime}, ) then ( A cdot lambda^{prime}>lambda ) B . ( lambda^{prime}=lambda ) c. ( lambda^{prime}<lambda ) D. none |
12 |

671 | When light waves suffers reflection at the interface from air to glass, the change in phase of reflected waves is equal to A . 0 в. ( frac{pi}{2} ) c. ( pi ) D. ( 2 pi ) |
12 |

672 | Consider a young’s doluble slit experiment as shown in figure. What should be the slit seperation din term of wavelength ( lambda ) such that the first minima occurs directly in front of the slit ( left(boldsymbol{S}_{1}right) ? ) ( A ) B. c. ( frac{lambda}{(sqrt{5}-2)} ) D. ( frac{lambda}{2(sqrt{5}-2)} ) |
12 |

673 | 18. If one of the two slits of Young’s double-slit experime is painted so that it transmits half the light intensity as second slit, then (a) the fringe system will altogether disappear (b) the bright fringes will become brighter and the dark fringes will become darker (c) both dark and bright fringes will become darker (d) dark fringes will become brighter and bright fringes darker |
12 |

674 | The amplitude of two interfering waves are ( a ) and ( 2 a ) respectively. The resultant amplitude in constructive interference will be ( mathbf{A} cdot 5 a ) B. ( a ) ( c cdot 3 a ) D. ( 2 a ) |
12 |

675 | The path difference between two wavefronts emitted by coherent sources ( o ) of wavelength ( 5460 A ) is 2.1 micron. The phase difference between the wavefronts at that point is A. 7.962 в. 7.962 ( pi ) c. ( frac{7.962}{pi} ) D. ( frac{7.962}{3 pi} ) |
12 |

676 | In Young’s double slit experiment, the two equally bright slits are coherent, but of phase difference ( frac{pi}{3} . ) If maximum intensity on the screen is ( I_{o} ), the intensity at the point on the screen equidistant from the slits is: A ( cdot I_{o} ) в. ( frac{I_{o}}{2} ) c. ( frac{I_{o}}{4} ) D. ( frac{3 I_{o}}{4} ) |
12 |

677 | In young’s double slit experiment ( beta ) is the fringe width and ( I_{o} ) is the intensity of the central bright fringe. What will be the intensity at a distance ( x ) from the central bright fringe? ( mathbf{A} cdot_{mathrm{l}_{o}} cos left(frac{x}{beta}right) ) B ( cdot cos ^{2}left(frac{x}{beta}right) ) ( ^{mathrm{c}} cdot_{1_{0} cos ^{2}}left(frac{pi x}{beta}right) ) D. ( left(frac{I_{o}}{4}right) cos ^{2} frac{pi x}{beta} ) |
12 |

678 | Write down four differences between interference and diffraction. |
12 |

679 | Draw the intensity pattern for single slit diffraction and double slit interference. Hence, state two differences between interference and diffraction patterns. |
12 |

680 | Consider an YDSE that has different slits width, as a result, amplitudes of waves from two slits are ( A ) and ( 2 A ) respectively. If ( I_{0} ) be the maximum intensity of the interference pattern, then intensity of the pattern at a point where phase difference between waves is ( phi ) is : ( mathbf{A} cdot I_{0} cos ^{2} phi ) B. ( frac{I_{0}}{3} sin ^{2} frac{phi}{2} ) c. ( frac{I_{0}}{9}[5+4 cos phi] ) D ( cdot frac{I_{0}}{9}[5+8 cos phi] ) |
12 |

681 | The following cannot be explained by wave nature of light A . Interference B. Photo electric effect c. Diffraction D. Refraction |
12 |

682 | At ( t=2 s, ) the position of central maxima is A. ( 2 m m ) above ( C ) B. ( 2 m m ) below ( C ) ( mathrm{c} .4 mathrm{mm} ) above ( C ) D. ( 4 m m ) below ( C ) |
12 |

683 | In single slit diffraction pattern A. Centre fringe has negligible width than others. B. All fringes are of same width C . Central fringe does not exist D. None of the above |
12 |

684 | Sketch the emergent wavefront | 12 |

685 | In Young’s double-slit experiment, the ( y- ) coordinates of central maxima and 10 th maxima are ( 2 c m ) and ( 5 c m ), respectively When the YDSE apparatus is immersed in a liquid of refractive index ( 1.5, ) the corresponding y-coordinates will be ( mathbf{A} cdot 2 c m, 7.5 c m ) B. ( 3 mathrm{cm}, 6 mathrm{cm} ) ( mathbf{c} .2 mathrm{cm}, 4 mathrm{cm} ) D. ( 4 / 3 c m, 10 / 3 c m ) |
12 |

686 | Young’s expt. the ratio of intensity at maxima and minima in the interference pattern is The ( 25: 9 . ) The ratio of slit width will be ( A cdot 4: 1 ) B. 2:1 ( c cdot 16: 1 ) D. 8: 1 |
12 |

687 | The fringe width for red colours as compared to that for violet colour is approximately A. 3 times B. 2 times c. 4 times D. 8 times |
12 |

688 | Unpolarised and Polarised Light. | 12 |

689 | 24. A plate of thickness t made of a material of refractive index u is placed in front of one of the slits in a double- slit experiment. What should be the minimum thickness t which will make the intensity at the center of the fringe pattern zero? (a) (u – 1) (b) (u – 1) 2 (C) 2(4-1) (d) – 4 (M-1) |
12 |

690 | A parallel beam of light of wavelength ( 560 mathrm{nm} ) falls on a thin of oil (refractive index ( =1.4 ) ) What should be the minimum thickness of the film so that it weakly transmits the light |
12 |

691 | In YDSE using monochromatic visible light, the distance between the plane of slits and the screen is ( 1.7 m . ) At point ( P ) on the screen which is directly in front of the upper slit, maximum path is observed. Now, the screen is moved ( 50 c m ) closer to the plane of slits. Point ( P ) now lies between third and fourth minima above the central maxima and the intensity at ( P ) is one-fourth of the maximum intensity on the screen. Find the wavelength of light if the separation of slits is ( 2 m m ) A. ( 2.9 times 10^{-7} mathrm{m} ) В. ( 3.9 times 10^{-7} mathrm{m} ) c. ( 5.9 times 10^{-7} m ) D. ( 6.9 times 10^{-7} ) т |
12 |

692 | 9. When an unpolarised light of intensity 1, is incident on a polarising sheet, the intensity of the light which does not get transmitted is (a) lo (b) zero (AIEEE 2005) |
12 |

693 | Two identical coherent sources are placed on a diameter of a circle of radius ( R ) at separation ( x(<<R) ) symmetrically about the centre of the circle. The sources emit identical wavelength ( lambda ) each. The number of points on the circle with maximum intensity is ( (x=5 lambda) ) |
12 |

694 | What will be the distance between two slits which, when illuminated by light of wavelength ( 5000 A^{circ}, ) produce fringes of width ( 0.5 m m ) on a screen distant 1 meter from the slits? ( mathbf{A} cdot 10^{-2} ) meter B . ( 10^{-3} ) meter ( mathbf{c} cdot 10^{-4} ) meter D. ( 10^{-6} ) meter |
12 |

695 | 7. Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 m. Approximately, what is the maximum distance at which these dots can be resolved by the eye? (Take wavelength of light as 500 nm.) (a) 3 m (b) 6 m (c) 1 m (d) 5 m (AIEEE 2005) |
12 |

696 | A beam of width ( t ) is incident at 45 o on air-water boundary. The width of the beam in water is |
12 |

697 | Sets of travellling waves are given as shown in above figure. Identify which of the following set of wave will soon show constructive interference? ( A cdot A ) B. B ( c cdot c ) D. E. |
12 |

698 | Sound waves from a tuning fork ( boldsymbol{F} ) reach a point ( boldsymbol{P} ) by two separate routes ( boldsymbol{F} boldsymbol{A} boldsymbol{P} ) and ( F B P . F B P ) is ( 12 mathrm{cm} ) larger than FAP.There is silence at ( P ). If the separation becomes ( 2 mathrm{cm} ), the sound becomes maximum at ( P ) and at ( 36 c m ) there is again silence and so on. The least frequency of tuning fork is A . 1357 Hz в. 1735 нz c. ( 1375 mathrm{Hz} ) D. 1400 нz |
12 |

699 | 17. A beam of unpolarised light of intensity 10 is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of the emergent light is: (a) 10/2 (b) 1/4 (c) 10/8 (d) I (JEE Main 2013) |
12 |

700 | For a parallel beam of monochromatic light of wavelength ( ^{prime} lambda^{prime}, ) diffraction is produced by a single slit whose width ‘a is of the order of the wavelength of the light. If ‘D’ is the distance of the screen from the slit, the width of the central maxima will be ( ^{text {A }} cdot frac{D a}{lambda} ) B. ( frac{2 D a}{lambda} ) c. ( frac{2 D lambda}{a} ) D. ( frac{D lambda}{a} ) |
12 |

701 | Fill in the blank with appropriate answer: In Young’s double slit experiment, the path difference between two interfering waves at a point on the screen is ( frac{5 lambda}{2}, lambda ) being wavelength of the light used. The dark fringe will lie at this point. |
12 |

702 | The bending of light near the edges of an obstacle and spreading into the region of geometrical shadow is called A . Interference B. Diffraction c. Polarization D. Doppler effect |
12 |

703 | In optical instruments, the lenses are used to form images by : A. Reflection B. Refraction c. Dispersion D. Scattering |
12 |

704 | In a YDSE with identical slits, the intensity of the central bright fringe is ( I_{0} . ) If one of the slits is covered, the intensity at the same point is A ( cdot 2 I_{0} ) в. ( I_{0} ) ( c cdot I_{0} / 2 ) D. ( I_{0} / 4 ) |
12 |

705 | In an interference experiment, monochromatic light is replaced by white light we will see: | 12 |

706 | Unpolarized light passes through two polaroids, the axis of one is vertical and that of the other is ( 30^{circ} ) to the vertical. What is the orientation and intensity of the transmitted light? A. Plane polarized at ( 60^{circ} ) to the vertical and having intensity ( frac{l_{0}}{4} ) B. Plane polarized at ( 30^{circ} ) to the vertical and having intensity of ( frac{3 l_{0}}{8} ) C. Plane polarized at ( 30^{circ} ) to the vertical and having intensity ( frac{l_{0}}{2} ) D. No light passes |
12 |

707 | Light of wavelength ( 6328 A ) is incident normally on a slit having a width of ( 0.2 m m . ) The angular width of the central maximum measured from minimum to minimum of diffraction pattern on a screen 9.0 meters away will be about A. 0.36 degree B. 0.18 degree c. 0.72 degree D. 0.09 degree |
12 |

708 | Monochromatic light is incident on a pair of narrow slits a distance of ( 0.1 mathrm{mm} ) apart. A series of bright and dark fringes are observed on a screen a distance of ( 2.0 mathrm{m} ) away. The distance between adjacent bright fringes is ( 8.0 mathrm{mm} ) What is the path difference between the light waves from the two slits that meet at the second order dark fringe? A ( cdot 2.0 times 10^{-7} mathrm{m} ) В. ( 4.0 times 10^{-7} mathrm{m} ) ( mathbf{c} cdot 6.0 times 10^{-7} m ) 7 |
12 |

709 | A parallel beam of monochromatic light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of the slit is : A. zero в. ( frac{pi}{2} ) ( c ) D. ( 2 pi ) |
12 |

710 | Which theory of light proposed the presence of ether medium for propogation of light? | 12 |

711 | 115410 monochromatic point source emitting light of wavelength ( lambda=500 ) nm. A thin lens of circular shape of focal length ( 0.10 m ) is cut into two identical halves ( L_{1} ) and ( L_{2} ) by a plane passing through a diameter. The two halves are placed symmetrically about the central axis SO with a gap of 0.5 mm. The distance along the axis from ( S ) to ( L_{1} ) and ( L_{2} ) is ( 0.15 m, ) while that from ( L_{1} ) and ( L_{2} ) to ( O ) is 1.30 m. The screen at ( O ) is normal to ( boldsymbol{S O} ) If the third intensity maximum occurs at point ( A ) on the screen, find distance OA in mm. |
12 |

712 | Two identical sound waves each of loudness ( beta ) interfere constructively at a point to produce a sound level of ( mathbf{A} cdot 6 beta ) B. ( 3 beta ) ( mathbf{c} cdot beta+3 ) ( mathbf{D} cdot beta+6 ) |
12 |

713 | The de Broglie wave present in fifth Bohr orbit is ( A ) в. ( c ) D. |
12 |

714 | If one of the two slits of Young’s doubleslit experiment is painted so that it transmits half the light intensity as the second slit, then A. fringe system will altogether disappear B. bright fringes will become brighter and the dark fringes will become darker c. both dark and bright fringes will become darker D. dark fringes will become less dark and bright fringes will become less bright |
12 |

715 | 12. Following transverse waves, y = 2sin (100 – 5.3x), y = 212 sin(100 – 5.3x+5) and y3 = sin (100t – 5.3x) superpose in a homogenous medium. Find the resultant amplitude at x = 0. (a) 1 unit (b) 4 unit (c) 5 unit (d) 2 unit |
12 |

716 | Light waves travel in a vacuum, along the ( X ) -axis. Which of the following may represent the wave fronts? ( mathbf{A} cdot x=c ) В. ( y=c ) ( mathbf{c} cdot z=c ) D. ( x+y+z=c ) |
12 |

717 | In Young’s double slit experiment, the two slits act as coherent sources of equal amplitude ( A ) and wavelength ( lambda ). In another experiment with the same set up the two slits are same of equal amplitude of wavelength ( lambda ) but are incoherent. The ratio of intensity of light at the mid point of the screen in the first to the second case is? A . 4: 1 B . 2: 1 ( c cdot 1: 1 ) D. 1: 2 |
12 |

718 | 8. If 1, is the intensity of the principal maximum in the single-slit diffraction pattern, then what will be its intensity when the slit width is doubled? 10 0 (b) 10 (c) 41 (d) 21 (AIEEE 2005) (a) 2 |
12 |

719 | The frequencies of two sound sources are ( 256 mathrm{Hz} ) and ( 260 mathrm{Hz}, ) At ( mathrm{t}=0, ) the intensity of sound is maximum. Then the phase differance at the time ( t=1 / 16 ) sec will be A. zero в. ( pi ) c. ( pi / 2 ) D. ( pi / 4 ) |
12 |

720 | ( M_{1} ) and ( M_{2} ) are plane mirrors and kept parallel to each other. At point 0 , there will be a maxima for wavelength ( lambda ). Light from a monochromatic source ( boldsymbol{S} ) of wavelength ( lambda ) is not reaching directly on the screen. Then, ( lambda ) is: ( ^{A} cdot frac{3 d^{2}}{D} ) B. ( frac{3 d^{2}}{text { on }} ) ( 2 D ) ( c cdot underline{d^{2}} ) ( bar{D} ) D. ( 2 d^{d} ) |
12 |

721 | Name any two characteristics of light explained by Huygens wave theory? | 12 |

722 | The intensity of the light coming from one of the slits in a Young’s double slit experiment is double the intensity from the other slit. Find the ratio of the maximum intensity to the minimum intensity in the interference fringe pattern observed. |
12 |

723 | 29. In a two-slit experiment with white light, a white fringe is observed on a screen kept behind the slits. When the screen in moved away by 0.05 m, this white fringe (a) does not move at all (b) gets displaced from its earlier position (c) becomes colored (d) disappears |
12 |

724 | A Young’s double slit experiment is conducted with slit separation ( 10 mathrm{mm} ) where the screen is ( 2 mathrm{m} ) away from the slits. If wavelength of light used is ( 6000 AA, ) then fringe width in ‘mm’ is A . 0.12 B. 0.24 c. 0.36 D. 0.48 |
12 |

725 | Two identical coherent sources of wavelength ( lambda ) are placed at ( (100 lambda, 0) ) and ( (-50 lambda, 0) ) respectively. A detector moves slowly from the origin to ( (50 lambda, 0) ) along x-axis. The number of maxima and minima detected are, respectively [include origin and ( (50 lambda, 0)] ) A. 51 and 50 B. 101 and 100 c. 49 and 50 D. 50 and 49 |
12 |

726 | 65. In a standard Young’s double-slit experiment with coherent light of wavelength 600 nm, the fringe width of the fringes in the central region (near the central fringe, Po) is observed to be 3 mm. An extremely thin glass plate is introduced in front of the 2= 600 nm first slit, and the fringes are observed to be displaced by 11 mm. Another thin plate is placed before the second slit and it is observed that the fringes are now displaced by an additional 12 mm. If the additional optical path lengths introduced are A, and A2, then (a) 1141 = 1242 (b) 124, = 1142 (c) 114, >1242 (d) none of the above |
12 |

727 | Two waves having the intensities in the ratio 9: 1 produce interference. The ratio of maximum to minimum intensity is equal to ( A cdot 4: 1 ) B. 9: 1 ( c cdot 2: ) D. 10: 8 |
12 |

728 | Green light is incident at the polarising angle on a certain transparent medium. The angle of refraction is ( 30^{circ} . ) Find (i) polarising angle, and (ii) refractive index of the medium. |
12 |

729 | An un-publicized beam of intensity ( 2 a^{2} ) passes through a thin Polaroid. Assuming zero absorption in the Polaroid the intensity of emergent planes polarized light is ( mathbf{A} cdot 2 a^{2} ) в. ( a^{2} ) c. ( sqrt{2} a^{2} ) D. ( frac{a^{2}}{2} ) |
12 |

730 | In YDSE ratio of width of slit is 4: 1 then ratio of maximum to minimum intensity ( mathbf{A} cdot mathbf{9} ) B . 27 ( c .3 ) D. 81 |
12 |

731 | 52. Unpolarized light falls on two polarizing sheets placed one on top of the other. What must be the angle between the characteristic directions of the sheets if the intensity of the final transmitted light is one-third the maximum intensity of the first transmitted beam (a) 75° (b) 55° (c) 35° d) 15° |
12 |

732 | If the angle between the pass axis of the polarizer and the analyzer is 45 the ratio of the intensities of original light and the transmitted light after passing through the analyzer is A ( cdot frac{I}{2} ) B. ( frac{1}{3} ) ( c ) D. ( frac{I}{4} ) |
12 |

733 | Two Nicols is oriented with their principal planes making an angle of ( 60^{circ} ) The percentage of incidents unpolarized light which passes through the system are ( A cdot 50 % ) B. ( 100 % ) c. ( 12.5 % ) D. 37.5% |
12 |

734 | To observe diffraction, the size of an obstacle: A. should be of the same order as wave length B. should be much larger than the wave length c. has no relation to wave length D. may be greater or smaller than the wave length |
12 |

735 | In Young’s double slit experiment the separation between the slits is halved and the distance between the slits and screen is doubled. The fringe width is: A. unchanged B. halvedd c. doubled D. quadrupled |
12 |

736 | Identify which of the following should be used for polarised light waves? I. Sunglasses Il. Remove ultraviolet light III. Reveal stress patterns A. I only B. II only c. I and III only D. II and III only E. I, II, and III |
12 |

737 | In Young’s double slit experiment if the slit widths are in the ratio ( 1: 9 . ) The ratio of the intensity at minima to that at maxima will be : A . в. ( frac{1}{9} ) ( c cdot frac{1}{4} ) D. ( frac{1}{3} ) |
12 |

738 | The wave front due to a source situated at infinity is : A. spherical B. cylindrical c. planar D. none of these |
12 |

739 | Two radio stations broadcast their program at the same amplitude ( A ) but at slightly different frequencies ( n_{1} ) and ( n_{2} ) such that ( left(n_{1}-n_{2}right)=10^{3} H z . ) detector receives signals from both the stations simultaneously but only when intensity of signal is greater than ( 2 A^{2} ) The time interval between two successive maxima will be : в. ( 10^{-2} ) s ( mathrm{c} cdot 10^{-3} s ) D. ( 10^{circ} ) |
12 |

740 | 68. In YDSE, light of wavelength 2 = 5000 Å is used, which emerges in phase from two slits a distance d = 3 x 10- m apart. A transparent sheets, 19 d sin of thickness t = 1.5 x 10-‘m, refractive index n = 1.17, is placed over one of the slits. Where does the central maxima of the interference now appear from the center of the screen? (Find the value of y?) D(u – 1) 2D (u – 1) (a) – 2d d D(u + 1) D(u – 1) d d |
12 |

741 | The radius of a wavefront as the waves propagate A. decreases B. increases c. becomes zero D. sometimes decreases and sometimes increases |
12 |

742 | Slit 1 of Young’s double-slit experiment is wider than slit ( 2, ) so that the light from slits are given as ( A_{1}=A_{0} sin omega t ) and ( A_{2}=A_{0} sin left(omega t+frac{pi}{3}right) . ) The resultant amplitude and intensity, at a point where the path difference between them is zero, are ( A ) and ( I ) respectively. Then This question has multiple correct options A ( cdot A=sqrt{3} A_{0} ) B ( cdot A=4 A_{0} ) ( mathbf{c} cdot I propto 16 A_{0}^{2} ) D. ( I propto 3 A_{0}^{2} ) |
12 |

743 | 1. The wavelengths of light used in an optical instrument are 2, = 4000 Å and is = 5000 Å, then the ratio of their respective resolving powers (corresponding to 2, and 2) (a) 16:25 (b) 9:1 (d) 5:4 (c) 4:5 (AIEEE 2002) |
12 |

744 | In Young’s experiment, the fringe width was found to be ( 0.4 m m ). If the whole apparatus is immersed in water of refractive index ( frac{4}{3}, ) the new fringe width in mm is : A. 0.25 B. 0.30 ( c cdot 0.40 ) D. 2.00 |
12 |

745 | State the conditions to get constructive and destructive interference of light. | 12 |

746 | Four light waves are represented by (i) ( y=a_{1} sin omega t ) (ii) ( y=a_{2} sin (omega t+varepsilon) ) (iii) ( y=a_{1} sin 2 omega t(text { iv }) y=a_{2} sin 2(omega t+ ) ( varepsilon ) We obtain sustained interference due to super-position of This question has multiple correct options ( A cdot ) (i) and (ii) B. (i) and (iii) c. (ii) and (iv) D. (iii) and (iv) |
12 |

747 | A satisfactory photographic print is obtained at a distance of ( 2 mathrm{m} ) from a 60 Cd lamp when the exposure time is 10 s. The time of exposure required for the same quality print at a distance ( 4 mathrm{m} ) from a 120 Cd lamp is: A. 5 s B. 10 s ( c cdot 20 s ) D. 25 s |
12 |

748 | 44. What will be the angular width of central maxima in Fraunhofer diffraction when light of wavelength 6000 Å is used and slit width is 12 x 10 cm. (a) 2 rad (b) 3 rad (c) 1 rad (d) 8 rad |
12 |

749 | In case of theory of light nature of light match the following: List – I List – II a) Light is a collection of e) Newton’s theory photons b) Light is a form of f) Huygen’s theory electromagnetic wave g) Maxwell’s c) Light is a wave d) Light is a stream of h) Max planck’s corpuscles theory ( mathbf{A} cdot mathrm{a}-mathrm{h} ; mathrm{b}-mathrm{g} ; mathrm{c}-mathrm{f} ; mathrm{d}-mathrm{e} ) B. ( a-e ; b-f ; c-g ; d-h ) C. ( a-g ; b-h ; c-g ; d-f ) D. ( a-h ; b-g ; c-e ; d-f ) |
12 |

750 | Two coherent light sources each of wavelength ( lambda ) are separated by a distance ( 3 lambda ). The maximum number of minima formed on line AB which runs from ( -infty ) to ( +infty ) is |
12 |

751 | In double-slit experiment using light wavelength ( 600 n m ), the angular width of a fringe formed on a distant screen is ( 0.1^{circ} . ) What is the spacing between the two slits? |
12 |

752 | Two coherent sources of intensity ratio 9: 4 produce interference. The intensity ratio of maxima and minima of the interference pattern is: ( mathbf{A} cdot 13: 5 ) B. 5: 1 c. 25: 1 D. 3: 2 |
12 |

753 | Blue light of wavelength 480 nm is most strongly reflected off a thin film of oil on a glass slab when viewed near normal incidence. Assuming that the index of refraction of the oil is 1.2 and that of the glass is ( 1.6, ) what is the minimum thickness of the oil film (other than zero)? This question has multiple correct options A . ( 100 n m ) B. 200nm c. 300 nm D. None |
12 |

754 | In Young’s double-slit experiment, the angular width of a fringe formed on a distant screen is ( 1^{circ} . ) The slit separation is ( 0.01 mathrm{mm} . ) The wavelength of the light is A. ( 0.174 mathrm{nm} ) в. 0.174 А c. ( 0.174 mu m ) D. ( 0.174 times 10^{-4} mathrm{m} ) |
12 |

755 | The light of wavelength ( 6328 A^{circ} ) is incident on a slit of width 0.2 mm perpendicularly, the angular fringe width will be: A ( cdot 0.36^{circ} ) B. ( 0.18^{circ} ) ( c cdot 0.72^{circ} ) D. ( 0.09^{circ} ) |
12 |

756 | Instead of using two slits, if we use two separate identical sodium lamps in Young’s experiment, which of the following will occur? A. General illumination B. Widely separate interference c. very bright maxima D. Very dark minima |
12 |

757 | The helical structures of nucleic acids can be studied by using: A. Interference phenomenon B. Diffraction pattern C. Polarised light D. Photoelectric effect |
12 |

758 | White light is used to illuminate the two slits b distance apart and the screen is placed at a distance directly in front of one of the slits on the screen. It is found that certain wavelength are missing then find the wavelength if ( (b<<d) ) |
12 |

759 | Two small loud speakers ( A ) and ( B ) are driven by the same amplifier as shown in Fig and emit pure sinusoidal waves in phase. Speaker ( A ) is ( 1 mathrm{m} ) away as shown and speaker ( B ) is 2 m away from the amplifier. The microphone is ( 4 mathrm{m} ) away from the amplifier in transverse direction as indicated in the Figure. For what frequencies destructive interference will occur at ( P: ) A. 500 HZ, 1500 нZ, 2500 Hz,… B. 500 Нz, 1000 Нz, 1500 Нz,… c. 1250 Нz, 1750 Нz, 2250 Нz,.. D. 1000 Hz, 2000 Hz |
12 |

760 | wavelength ( 6000 A ) is placed at a very small height h above a flat reflecting surface ( M N ) as shown in the figure. The intensity of the reflected light is ( 36 % ) of the incident intensity. Inference fringes are observed on a screen placed paralle to the reflecting surface at a very large distance ( D ) from it. If the intensity at ( p ) be maximum, then the minimum distance through which the reflecting surface ( M N ) should be displaced so that at ( P ) again becomes maximum? ( A cdot 3 times 10^{-7} mathrm{m} ) B . ( 6 times 10^{-7} mathrm{m} ) C. ( 1.5 times 10^{-7} mathrm{m} ) D. ( 12 times 10^{-7} mathrm{m} ) |
12 |

761 | In a YDSE apparatus, if we use while light then : A. the fringe next to the central will be red B. the central fringe will be white c. the fringe next to the central will be violet D. there will not be a completely dark fringe |
12 |

762 | At the first minimum adjacent to the central maximum of a single – slit diffraction pattern, the phase difference between the Huygen’s wavelet form the edge of the slit and the wavelet from the midpoint of the slit is: A ( cdot frac{pi}{8} ) radian B . ( frac{pi}{4} ) radian c. ( frac{pi}{2} ) radian D. ( pi ) radian |
12 |

763 | A Young’s interference experiment is performed with monochromatic light. The separation between the slits is ( 0.5 m m, ) and the interference pattern on a screen is ( 3.5 m ) away, shows the first order maximum at ( 3.6 m m ) from the centre of the pattern. The wavelength is A ( .515 n m ) B. ( 315 mathrm{mm} ) c. 215 cm D. ( 15 m ) |
12 |

764 | A light of wavelength ( lambda ) is incident on an object of size b. If a screen is at a distance D from the object. Identify the correct condition for the observation of different phenomenon: a) if ( b^{2}=D lambda ), Fresnel diffraction is observed b) if ( b^{2}>>D lambda ), Fraunhoffer diffraction is observed c) if ( b^{2}<<D lambda ), Fraunhoffer diffraction is observed d) if ( b^{2}=D lambda, ) Fraunhoffer diffraction is observed A. a, b and d are true B. a,c and d are true ( c cdot ) a and c are true D. a and d are true |
12 |

765 | What change, if any, is observed in frequency and wavelength when light travels fro air to glass? |
12 |

766 | Which of the following undergo maximum diffraction? A. ( alpha- )rays B . ( gamma- ) rays c. radio waves D. light waves |
12 |

767 | Two sound sources of sound are placed along the diameter of a circle of radius ( boldsymbol{R}(boldsymbol{R}>>mathbf{4} boldsymbol{lambda}) ) How many minima will be heard as one moves along the perimeter of circle? ( A cdot 16 ) В. 12 ( c cdot 4 ) ( D ) |
12 |

768 | ( A ) is singing a note and at the same time ( B ) is also singing a note with 1 / 8 the frequency of ( A ). The energies of the two sounds are equal. The disparagement amplitude of the note if ( boldsymbol{B} ) is: A. same as that of ( A ) B. Twice that of ( A ) c. four times that of ( A ) D. eigth times that of ( A ) |
12 |

769 | How does the angular separation between fringes in single slit diffraction experiment change when the distance of separation between the slit and screen is doubled? | 12 |

770 | Give the essential conditions (any two) for the source to be Coherent. (b) In Young’s double slit experiment, using monochromatic light of wavelength ( lambda ) the intensity of light at a point on the screen where path difference is I, is ( 2 K ) units. Find out the intensity of light at a point where path difference is ( lambda / 6 ) |
12 |

771 | State Huygen’s principle, Using this principle draw a diagram to show how a plane wave front incident at the interface of the two media gets refracted when it propagates from a rarer to a denser medium.Hence verify Snell’s law of refraction |
12 |

772 | In Young’s double-slit experiment ( boldsymbol{d} / boldsymbol{D}=mathbf{1 0}^{-4}(boldsymbol{d}= ) distance between slits, ( D= ) distance of screen from the slits). At point ( P ) on the screen resulting intensity is equal to the intensity due to the individual slit ( boldsymbol{I}_{0} ) Then, the distance of point ( P ) from the central maximum is ( (boldsymbol{lambda}=mathbf{6 0 0 0} boldsymbol{boldsymbol { A }}) ) ( mathbf{A} cdot 2 m m ) B. ( 1 mathrm{mm} ) ( mathrm{c} .0 .5 mathrm{mm} ) D. ( 4 mathrm{mm} ) |
12 |

773 | A sound source emits two sinusoidal sound waves. both of wavelength ( lambda ) along paths ( A ) and ( B ) as shown in figure The sound travelling along path ( B ) is reflected from five surfaces as shown and then merges at point ( Q ), producing minimum intensity at that point. Find the minimum value of ( d ) in terms of ( lambda ) |
12 |

774 | Which of the following phenomena can be demonstrated by light. But not with sound waves in an air column? A . Reflection B. Diffraction c. Refraction D. Polarization |
12 |

775 | The transverse nature of light is shown by A. interference of light B. refraction of light c. polarization of light D. dispersion of light |
12 |

776 | A beam of light of wavelength 600 nm from a distance source falls on a single slit 1 mm wide and a resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of central bright fringe is ( mathbf{A} cdot 1.2 mathrm{cm} ) B. ( 1.2 m m ) c. ( 2.4 c m ) D. ( 2.4 m m ) |
12 |

777 | Explain the construction of plane wavefront using Huygen’s principle. | 12 |

778 | A thin sheet of glass ( (mu=1.5) ) of thickness 6 micron introduced in the path of one of the interfering beams in a double slit experiment shifts the central fringe to a position previously occupied by fifth bright fringe. The the wavelength of light used is A ( cdot 6000 stackrel{circ}{A} ) в. 3000 , ( c cdot 4500 stackrel{circ}{A} ) D・7500 ( stackrel{circ}{A} ) |
12 |

779 | If in a Young’s double slit experiment, the slit width is ( 3 mathrm{cm}, ) the separation between slits and screen is ( 70 mathrm{cm} ) and wavelength of light is ( 1000 mathrm{A} ), then fringe width will be ( (mu=1.5) ) A ( .2 .3 times 10^{-3} mathrm{cm} ) В. ( 2.3 times 10^{-4} m ) ( mathbf{c} cdot 2.3 times 10^{-5} mathrm{cm} ) D . ( 2.3 times 10^{-6} mathrm{m} ) |
12 |

780 | Two slits separated by a distance of 1 ( m m ) are illuminated by light of wavelength ( 6.5 times 10^{-7} ) m. Interference fringes are oberved on a screen placed at a distance of 1 from the slits. Calculate the distance between the third dark fringe and fifth bright fringe. |
12 |

781 | State whether true or false: During destructive interference, the crest of one wave meets the trough of the other wave. A. True B. False |
12 |

782 | Two waves are propagating along a taut string that coincides with the ( x ) -axis. The first wave has the wave function ( boldsymbol{y}_{1}=boldsymbol{A} cos [boldsymbol{k}(boldsymbol{x}-boldsymbol{v} boldsymbol{t})] ) and the second has the wave function ( y_{2}=A cos [k(x+ ) ( boldsymbol{v} boldsymbol{t})+boldsymbol{phi}] ) A. For constructive interference at ( x=0, phi=pi ) B. For constructive interference at ( x=0, phi=3 pi ) c. For destructive interference at ( x=0, phi=pi ) D. For destructive interference at ( x=0, phi=2 pi ) |
12 |

783 | State brewsters law. The value of brewster’s angle for a transparent medium is different for light of different colours. give reason? |
12 |

784 | At the centre ( (t=0) ) of Newton’s ring arrangement, we observe a A. dark spot B. bright spot c. coloured spot D. None of these |
12 |

785 | You are provided with a narrow and parallel beam of light. State how you will determine experimentally, whether it is a beam of ordinary(unpolarised) light, partially polarised light or completely polarised light. | 12 |

786 | A ray of light travelling in impure water is incident on a glass plate immersed in it. When the angle of incidence is ( 51^{circ} ) the reflected ray is totally plane polarized. Given that refractive index of impure water if ( 1.4 . ) The refractive index of glass should be ( left(tan 51^{circ}=1.235right) ) A . 1.64 в. 1.34 c. 1.53 D. 1.73 |
12 |

787 | Electron microscope, the biggest innovation in microscopy was built on principle of A. wave nature of electrons B. total internal reflection of light c. thin film optical interference D. light amplification by stimulated emission of radiation |
12 |

788 | 53. Two polaroids are placed in the path of unpolarized beam of intensity Isuch that no light is emitted from the second polaroid. If a third polaroid whose polarization axis makes an angle with the polarization axis of first polaroid, is placed between these polaroids then the intensity of light emerging from the last polaroid will be (c) (1 cosa 20 (d) 1, cosa e |
12 |

789 | 12. The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index n) is (a) sin (n) (b) sin-‘ (1/n) (c) tan-(1/n) (d) tan-‘(n) (AIEEE 2004) |
12 |

790 | Fill in the blanks with suitable words: Light has and nature. |
12 |

791 | In Young’s double slit experiment with monochromatic source of light of wavelength ( 6000 A^{circ} ), if the path difference is ( 1.5 times 10^{-6} m, ) the point becomes: A. bright band B. dark band c. sometimes bright and sometimes dark D. data insufficient |
12 |

792 | A parallel beam of diameter ( d ) is incident on air-glass interface as shown in figure. The diameter of refracted light beam is: ( left(boldsymbol{d}=mathbf{3} boldsymbol{m} boldsymbol{m}, boldsymbol{theta}=mathbf{4} mathbf{5}^{mathbf{0}} text { and } frac{boldsymbol{n}_{boldsymbol{g} operatorname{lass}}}{boldsymbol{n}_{boldsymbol{a} i boldsymbol{r}}}=frac{boldsymbol{3}}{boldsymbol{2}}right) ) ( A cdot sqrt{12} m m ) В. ( sqrt{14} ) тт ( c cdot sqrt{6} m m ) D. ( 4.5 mathrm{mm} ) |
12 |

793 | Newton postulated his corpuscular theory of light on the basis of A. Newton’s rings B. Rectilinear propagation of light c. colour through thin flims D. Dispersion of white light into columns |
12 |

794 | A glass of refractive index 1.5 is coated with a thin layer of thickness of ( t ) of refractive index 1.8 light of wavelength ( lambda ) tavelling at the upper and the lower surfaes of the layer and the two reflected rays interfere. If ( boldsymbol{lambda}=mathbf{6 4 8 n m} ) obtain the least value of ( tleft(operatorname{in} 10^{-8} mright) ) for which the rays interfere constructively. |
12 |

795 | In a biprism experiment the distance between the two virtual images of the slit is ( 0.1 mathrm{cm} ) and the distance between the slit and screen is ( 1 mathrm{m} ). If the band width is ( 0.058 mathrm{cm} . ) Calculate the wavelength of light. |
12 |

796 | Consider a light beam incident from air to a glass slab at Brewster’s angle as shown in figure. A polaroid is placed in the path of the emergent ray at point ( mathrm{P} ) and rotated about an axis passing through the centre and perpendicular to the plane of the polaroid. A. For a particular orientation there shall be darkness as observed through the polaroid B. The intensity of light as seen through the polaroid shall be independent of the rotation c. The intensity of light as seen through the polaroid shall go through a minimum but not zero for two orientations of the polaroid D. The intensity of light as seen through the polaroid shall go through a minimum for four orientations of the polaroid. |
12 |

797 | thickness as shown in figure. One is made pf material ( boldsymbol{A} ) of refractive index 1.5. The other is made of two materials ( B ) and ( C ) with thickness in the ratio 1: 2 The refractive index of ( C ) is ( 1.6 . ) If a monochromatic parallel beam passing through the slabs has the same number of wavelengths inside both, the refractive index of ( boldsymbol{B} ) is ( mathbf{A} cdot 1.1 ) B. 1.2 c. 1.3 D . 1.4. |
12 |

798 | Fill in the blanks: According to Newton, different colors of light are due to the difference in of the corpuscles. A. mass B. nature c. shape D. size |
12 |

799 | Photoelectric effect supports quantum nature of light because This question has multiple correct options A. there is a maximum frequency of light below which no photoelectrons are emitted B. the maximum kinetic energy of photoelectrons depends only on the frequency of light and not on its intensity C. even when the metal surface is faintly illuminated, the photoelectrons leave the surface immediately D. electric charge of the photoelectrons is quantized |
12 |

800 | A plane wave front falls on a convex lens The emergent wave front is : A. plane B. cylindrical c. spherical diverging D. spherical converging |
12 |

801 | The polarising angle for glass is: A. same for different kinds of glass B. different for different kinds of glass C. same for lights of all colours D. varies with time |
12 |

802 | Find the ( x ) -coordinates on the ( x ) -axis. (excluding ( boldsymbol{x}=mathbf{0} ) and ( boldsymbol{x}=infty ) This question has multiple correct options A. ( x=4 lambda ) B . ( x=7 lambda / 4 ) c. ( x=5 lambda / 4 ) D. ( x=3 lambda ) |
12 |

803 | For what distance ray optics a good approximation when the aperture is 4 ( mathrm{mm} ) wide and the wavelength is ( 500 n m ? ) A . ( 32 m ) B. ( 69 m ) ( c .16 m ) D. ( 8 m ) |
12 |

804 | If in Young’s double slit experiment, the distance between the two slits is halved and the distance between the slit and screen id doubled, then the fringe width will become A . half B. double c. four times D. unchanged |
12 |

805 | 9. Laser beams are used to measure long distances because (a) They are monochromatic (b) They are highly polarised (c) They are coherent (d) They have high degree of parallelism |
12 |

806 | Light travels faster in air than that in glass. This is accordance with A. wave theory of light B. corpuscular theory of light c. neither (a) nor (b) D. Both (a) and (b) |
12 |

807 | Light, like sound, cannot pass through vacuum. State whether true or false A. True B. False |
12 |

808 | Which of the following statements about the behaviour of light is not correct? A. Interference patterns are evident for light behaving as rays. B. Ray properties of light are useful for understanding how images are formed by optical devices such as eyes. C. Wave properties are important for observing the behaviour of light at a fine scale. D. Both wave and particle theories of light can be related to the colour sensations produced by light. |
12 |

809 | The box of a pinhole camera of length ( L ) has a hole of radius a. It is assumed that when the hole is illuminated by a parallel beam of light of wavelength ( lambda ) the spread of the spot (obtained on the opposite wall of the camera) is the sum of its geometrical spread and the spread due to diffraction. The spot would then have its minimum size say ( boldsymbol{b}_{m i n} ) when: ( ^{mathrm{A}} cdot_{a}=frac{lambda^{2}}{L} ) and ( b_{min }=frac{2 lambda^{2}}{L} ) B. ( a=sqrt{lambda L} ) and ( b_{min }=frac{2 lambda^{2}}{L} ) C ( . a=sqrt{lambda L} ) and ( b_{min }=sqrt{4 lambda L} ) D. ( a=frac{lambda^{2}}{L} ) and ( b_{m i n}=sqrt{4 lambda L} ) |
12 |

810 | If the width of slit is gradually increased, it will be observed experimentally that : A. bright fringes become reduced in intensity B. bright fringes become increased in intensity c. the intensity of minima is strictly zero D. the fringes become more distinct |
12 |

811 | Angular width of principal maximum in Fraunhoffer single slit diffraction is 0.1 radian. Angular width of secondary maxima is then A . 0.05 radian B. 0.1 radian c. 0.5 radian D. 0.25 radian |
12 |

812 | What is not an essential condition for an observable interference pattern to occur between the waves two sources? A. The frequencies of the two sources must be equal B. The sources must be coherent c. The sources must emit waves of equal amplitide D. The waves from the two sources must overlap |
12 |

813 | In young’s experiment, the fringe width at a distance of ( 50 mathrm{cm} ) from the slits, of light of wavelength ( 6000 AA ) is ( 0.048 mathrm{cm} ) The fringe width at the same distance for ( lambda=5000 AA ) will be : A . ( 0.04 mathrm{cm} ) B. ( 0.4 mathrm{cm} ) ( c .0 .14 c m ) D. ( 0.45 mathrm{cm} ) |
12 |

814 | Consider a tank made of glass(refractive index 1.5 ) with a thick bottom. It is filled with a liquid of refractive index ( mu . ) A student finds that, irrespective of what the incident angle (see figure) is for a beam of light entering the liquid, the light reflected from the liquid glass interface is never completely polarized. For this to happen the minimum value of ( mu ) is : A ( cdot frac{3}{sqrt{5}} ) в. ( frac{5}{sqrt{3}} ) c. ( sqrt{frac{5}{3}} ) ( D ) |
12 |

815 | In Young’s double slit experiment with sodium vapour lamp of wavelength 589 tun and the slits 0.689 min apart, the half angular width of the central maximum is A ( cdot sin ^{-1}(0.01) ) B. ( sin ^{-1}(0.0001) ) c. ( sin ^{-1}(0.001) ) D. ( sin ^{-1}(0.1) ) |
12 |

816 | Visible light of wavelength ( 6000 times ) ( 10^{-8} mathrm{cm} ) falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at ( 60^{0} ) from the central maximum. if the first minimum is produced at ( theta_{1} ) then ( theta_{1} ) is close to : A ( cdot 25^{circ} ) B. ( 30^{circ} ) ( c cdot 20^{0} ) D. ( 45^{circ} ) |
12 |

817 | To demonstrate the phenomenon of interference we require two soruces which emit radiation of A. nearly the same frequency B. the same frequency c. different wavelength D. the same frequency and having a definite phase relationship. |
12 |

818 | A plane polarized light is incident normally on the tourmaline plate. Its ( overrightarrow{boldsymbol{E}} ) vectors, make an angle of ( 60^{circ} ) with the optic axis of the plate. Find the ( % ) difference between initial and final maximum values of ( overrightarrow{boldsymbol{E}} ) vectors. |
12 |

819 | Ray optics is valid when characteristic dimensions are A. of the same order as the wavelength of light B. much smaller than the wavelength of light c. much larger than the wavelength of light D. of the order of ( 1 mathrm{mm} ) |
12 |

820 | A parallel beam of light of 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen ( 1 mathrm{m} ) away. It is observed that the first minimum is at a distance of 2.5 ( mathrm{mm} ) from the centre of the screen. Calculate the width of the slit. |
12 |

821 | 21. In Young’s double-slit experiment dID= 104 (d = distan between slits, D = distance of screen from the slits At point P on the screen, resulting intensity is equal to the intensity due to the individual slit Io. Then, the distance of point P from the central maximum is (a = 6000 Å) (a) 2 mm (b) 1 mm (c) 0.5 mm (d) 4 mm |
12 |

822 | si St 2 m 10. Two point sources separated by 2.0 m are radiating in phase with a = 0.50 m. A detector moves in a circular path around the two sources in a plane containing them. How many maxima are detected? (a) 16 (b) 20 (c) 24 (d) 32 |
12 |

823 | Light of wave length ( lambda ) air enters into two medium of refractive indices ( mu ) and ( mu / 2 . ) Two points ( P_{1} ) and ( P_{2} ) lying along the path of this light as shown in the figure. The phase difference between these two point is ( k frac{left(pi mu X_{0}right)}{lambda} . ) Then find the value of ( mathrm{k} ) ( A ) B. ( c .5 ) D. E. None of thes |
12 |

824 | 50. When an unpolarized light of intensity 1 is incident on a polarizing sheet, the intensity of the light which does not get transmitted is (a) Zero (b) 10 (C) 40 (c) -10 |
12 |

825 | A screen is placed ( 2 mathrm{m} ) away from a single narrow slit. The slit width if the first minimum lies ( 5 mathrm{mm} ) on either side of the central maximum is: (wave length ( =5000 A^{circ} ) ) A . ( 0.01 mathrm{cm} ) B. ( 0.02 mathrm{cm} ) ( c .0 .03 c m ) D. ( 0.04 mathrm{cm} ) |
12 |

826 | 8. Microwaves from a transmitter are directed toward a plane reflector. A detector moves along the normal to the reflector. Between positions of 14 successive maxima, the detector travels a distance of 0.14 m. What is the frequency of transmitter? (a) 1.5 x100 Hz (b) 3.0 x100 Hz (c) 1.5 x100 Hz (d) 3.0 x10° Hz TIL. 11 |
12 |

827 | P u) 2 unit 13. Two coherent narrow slits emitting light of wavelength 2 in the same phase are placed parallel to each other at a small separation of 32. The light is collected on a screen S which is placed at a distance D (>>2) from the slits. The smallest distance x such that the P is a maxima. (a) √30 gan (b) √80 (c) √50 (d) 75 N |
12 |

828 | Which theory explains all the characteristics of light? | 12 |

829 | Monochromatic green light of wavelength 550 nm illuminates two parallel narrow slits ( 7.7 mu mathrm{m} ) apart. The angular deviation ( theta ) of third order (for ( m ) ( =3 ) ) bright fringe in radian and in degrees respectively are: A ( .21 .6,12.4^{circ} ) в. ( 0.216,1.24^{circ} ) c. ( 0.216,12.4^{circ} ) D. ( 216,1.24^{circ} ) |
12 |

830 | A polarizer and an analyzer are oriented so that the maximum amount of lights is transmitted. Fraction of its maximum value is the intensity of the transmitted light reduced when the analyzer is rotated through (intensity of incident light ( =boldsymbol{I}_{boldsymbol{o}} boldsymbol{)} ) a) ( 30^{circ} ) b) ( 45^{circ} ) c) ( 60^{circ} ) A ( .0 .375 I_{0}, 0.25 I_{0}, 0.125 I_{0} ) B. ( 0.25 I_{0}, 0.375 I_{0}, 0.125 I_{0} ) C ( cdot 0.125 I_{0}, 0.25 I_{0}, 0.0375 I_{0} ) D. ( 0.125 I_{0}, 0.375 I_{0}, 0.25 I_{0} ) |
12 |

831 | Why don’t we have interference when two candles are placed close to each other and the intensity is seen at a distant screen? What happens if the candles are replaced by laser sources? |
12 |

832 | 19. Two beams, A and B. of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity) a rotation of polaroid through 300 makes the two beams appear equally bright. If the initial intensities of the two beams are 1A and Ig respectively, then I ll, equals (b) 1/3 (C) 3 (d) 3/2 (JEE Main 2014) (a) 1 |
12 |

833 | A beam of light containing two wavelengths ( 5200 A ) and ( 6500 A ) is used in Young’s experiment to obtain interference fringes. What is the least distance from the central maximum on the screen where the bright fringes due to both wavelengths concide? (Given distance between slits is 2 ( mathrm{mm} ) and distance of screen from slits is 120 ( mathrm{mm} ) A. ( 0.156 mathrm{mm} ) B. ( 0.312 mathrm{mm} ) ( c .0 .78 mathrm{mm} ) D. ( 1.1 mathrm{mm} ) |
12 |

834 | If ( theta ) is the polarizing angle for a medium in which the speed of light is ( v ), then according to Brewster’s Law: ( mathbf{A} cdot theta=sin ^{-1}(c / v) ) B ( cdot theta=tan ^{-1}(c / v) ) ( mathbf{c} cdot theta=cos ^{-1}(c / v) ) D. ( theta=sin ^{-1}(v / c) ) |
12 |

835 | Resolving power of a telescope increases with: A. increase in focal length of eyepiece B. increase in focal length of objective C. increase in aperture of eyepiece D. increase in aperture of objective |
12 |

836 | The phenomenon of rotation of plane polarized light is called A. Kerr effect B. Double refraction c. optical activity D. Dichroism |
12 |

837 | Thin film interference happens with This question has multiple correct options A. point or spherical source B. board source C. film thickness of the order of 10,000 A D. very thick transparent slabs |
12 |

838 | a) Using the phenomenon of polarization, show how transverse nature of light can be demonstrated. b) Two polaroids ( P_{1} ) and ( P_{2} ) are placed with their pass axes perpendicular to each other. Unpolarised light of intensity ( I_{0} ) is incident on ( P_{1} . ) A third Polaroid ( P_{3} ) is kept in between ( P_{1} ) and ( P_{2} ) such that its pass axis makes an angle of ( 30^{circ} ) with that of ( P_{1} ). Determine the intensity of light transmitted through ( P_{1}, P_{2} ) and ( P_{3} ) |
12 |

839 | A beam of light of wavelength 600 nm from a distant source falls on a single slit ( 1 mathrm{mm} ) wide and the resulting diffraction pattern is observed on a screen ( 2 mathrm{m} ) away. The distance between the first dark fringes on either side of the central bright fringe is? A . ( 1.2 mathrm{cm} ) B. ( 1.2 mathrm{mm} ) ( c .2 .4 mathrm{cm} ) D. ( 2.4 mathrm{mm} ) |
12 |

840 | The maximum intensity in Young’s double slit experiment is ( I_{0} . ) Distance between the slits is ( d=5 lambda ), where ( lambda ) is the wavelength of monochromatic light used in the experiment. What will be the intensity of light in front of one of the slits on a screen at a distance ( D=10 d ) ( ? ) A ( . I_{0} ) в. ( I_{0} / 4 ) c. ( _{overline{4}_{l_{0}}^{I_{0}}} ) D. ( I_{0} / 2 ) |
12 |

841 | In double refraction: A. the velocity of the E-ray varies with direction B. e-ray does not obey Snell’s law C ( . mu ) of E-ray is constant D. both ( A ) and ( B ) |
12 |

842 | 2. Figure shows wavefront P passing through two systems A and B, and emerging as Q and then as R. The systems A and B could, respectively, be (a) a prism and a convergent lens / (b) a convergent lens and a prism (c) a divergent lens and a prism (d) a convergent lens and a P A divergent lens Oі В |
12 |

843 | Assertion ( (A): ) Microwaves are better carries of signals than optical waves Reason ( (boldsymbol{R}): ) Microwaves move faster than optical waves A. Both ( A ) and ( R ) are true and ( R ) is correct explanation of ( A ) B. Both ( A ) and ( R ) are true and ( R ) is not the correct explanation of c. ( A ) is true but ( R ) is false D. ( A ) is false but ( R ) is true |
12 |

844 | 1: Primary waves can travel in all directions in an ether 2: Secondary waves can travel only in backward in an ether A ( . ) 1 is true, 2 is false B. Both 1 and 2 are true c. 1 is false, 2 is true D. Both 1 and 2 are false |
12 |

845 | Distinguish between interference and diffraction. | 12 |

846 | Wavefront is the locus of all points, where the particles of the medium vibrate with the same. A . phase B. amplitude c. frequency D. period |
12 |

847 | are drawn on light rays to show the direction in which light travels. | 12 |

848 | Explain how an unpolarised light gets polarised when incident on the interface separating the two transparent media. | 12 |

849 | Bichromatic light is used in YDSE having wavelengths ( lambda_{1}=400 n m ) and ( lambda_{2}=700 n m . ) Find the minimum order of ( lambda_{1} ) which overlaps with ( lambda_{2} ) |
12 |

850 | a parallel glass slab at a point ( A, ) as shown in the given figure. It undergoes partial reflection and refraction. At each reflection ( 25 % ) of incident energy is reflected. The rays ( A B ) and ( A^{prime} B^{prime} ) undergo interference. The 1 max ratio ( frac{text { nunce is }}{text { : }} ) is ( boldsymbol{I}_{m i} ) ( A cdot 4: 1 ) B. 8: 1 c. 7: 29 |
12 |

851 | In Young’s double slit experiment with monochromatic source of light of wavelength ( 6000 A^{circ}, ) if the path difference at a point on the screen is 6 ( times 10^{-6} m ) the number of the bright band formed at that point is: ( A cdot 2 ) B. 4 ( c cdot 6 ) D. 10 |
12 |

852 | In a fresnel’s bi-prism experiment, the refracting angles of the prism were ( 2.5^{circ} ) and the refracting index of the glass was ( 1.5 . ) With the single slit ( 10 mathrm{cm} ) from the bi-prism ,fringes were formed on a screen ( 1 mathrm{m} ) from the single slit. The fringe width is ( 0.1375 mathrm{mm} ). The wavelength of light is A. 600 nm B. 1200 nm c. ( 60 A^{circ} ) D. 120 A |
12 |

853 | Calculate the wave number and frequency of radiation having wavelength ( 5800 lambda ) ( left(172400 c m^{-1}, 5.172 times 10^{14} c y operatorname{cles} s^{-1}right) ) |
12 |

854 | If yellow light emitted by sodium lamp in Young’s double slit experiment is replaced by monochromatic blue light of same intensity keeping other parameters constant the new fringe width will : A. Remain unchanged B. Increase c. Decrease D. Can’t be predicted |
12 |

855 | In Fraunhofer diffraction pattern, slit width is ( 0.2 m m ) and screen is at ( 2 m ) away from the lens. If wavelength of light used in ( 5000 A ) then the distance between the first minimum on either side of the central maximum is ( (boldsymbol{theta} ) is small and measure in radian): A ( cdot 10^{-1} m ) B. ( 10^{-2} ) m c. ( 2 times 10^{-2} m ) D. ( 2 times 10^{-1} m ) |
12 |

856 | Newton postulated his corpuscular theory of light on the basis of: A. Newton’s rings. B. rectilinear propagation of light c. colour through thin films. D. Dispersion of white light into colours. |
12 |

857 | State Brewster’s law of polarisation of light. The polarising angle for a transparent medium is ( 60^{circ} . ) What will be the refractive index and angle of refraction of the medium? ( tan 60^{circ}=sqrt{3} ) |
12 |

858 | In an experiment, the amplitude of intensity variation of two sources is focused to be ( 3 % ) of the avg. intensity. Find the ratio of intensity of two interfering sources. |
12 |

859 | Two coherent point sources ( S_{1} ) and ( S_{2} ) vibrating in phase emit light of wavelength ( lambda ). The separation between the sources is ( 2 lambda ). Consider a line passing through ( S_{2} ) and perpendicular to the line ( S_{1} S_{2} ). What is the smallest distance from ( S_{2} ) where a minimum of intensity occurs? |
12 |

860 | Two wave-fronts are emitted from coherent sources of path difference between them is 2.1 micron. Phase difference between the wave-fronts at that point is ( 7.692 pi . ) Wavelength of light emitted by sources will be : в. 5400 月 c. ( 5460 hat{h} ) D. 5892 月 |
12 |

861 | Distinguish between linearly polarised and unpolarised light. | 12 |

862 | 46. Angular width of central maxima in the Fraunhofer diffraction pattern of a slit is measured. The slit is illuminated by light of wavelength 6000 A. When the slit is illuminated by light of another wavelength, the angular width decreases by 30%. The wavelength of this light will be (a) 6000 Å (b) 4200 Å (c) 3000 Å (d) 1800 Å |
12 |

863 | Name the phenomenon which is responsible for bending of light around sharp corners of an obstacle. Under what conditions does this phenomenon take place? | 12 |

864 | Unpolarized red light is incident on the surface of a lake at incident angle ( boldsymbol{theta}_{boldsymbol{R}} ) An observer seeing the light reflected from the water surface through a polarizer notices that on rotating the polarizer, the intensity of light drops to zero at a certain orientation. The red light is replaced by unpolarized blue light. The observer sees the same effect with reflected blue light at incident angle ( theta_{s} . ) Then : A ( cdot theta_{B}<theta_{R}theta_{R}>45^{circ} ) ( mathbf{D} cdot theta_{R}>theta_{B}>45^{circ} ) |
12 |

865 | Thin films like soap bubbles and oil floating on water can create colorful patterns. Which of the following explanations most accurately describes why this happens? A. Thin films contain many different colored chemicals B. Thin films diffract and refract light so that it sets up interference patterns c. Thin films provide reflection from the front and back surfaces, and this creates interference patterns D. Thin films polarize light which interferes with the unpolarized light to create colors E. Thin films absorb some colors and allow others to reflect |
12 |

866 | varv VC vuuduleury using suurcos Jud 7. Two light waves having the same wavelength 2 in vacuum are in phase initially. Then the first ray travels a path of length L, through a medium of refractive index u,. The second ray travels a path of length L, through a medium of refractive index Uly. The two waves are then combined to observe interference effects. The phase difference between the two, when they interfere, is 27 (a) (L,-1) 14 – My L2) 27 (c) 24 (UsL – 44L) (a) 2 |
12 |

867 | For which colour is the fringe width minimum? A . violet B. red c. green D. yellow |
12 |

868 | If the wavelength of light used is 6000 A. The angular resolution of telescope of objective lens having diameter ( 10 mathrm{cm} ) is rad A ( cdot 7.52 times 10^{-6} ) в. ( 6.10 times 10^{-6} ) c. ( 6.55 times 10^{-6} ) D. ( 7.32 times 10^{-6} ) |
12 |

869 | Light waves can be polarised because they A. have high frequencies B. have short wavelength c. are transverse D. can be reflected |
12 |

870 | Two waves of amplitudes ( A ) and ( 3 A ) are superposed and they have a phase difference of ( 2 pi . ) What kind of interference is possible A. constructive interference B. Destructive interference c. Interference depends on wavelength difference D. Interference depends on frequency difference |
12 |

871 | A slit of width ( a ) is illuminated by white light. The first minimum for red light ( (lambda ) ( =6500 A) ) will fall at ( theta=30^{circ} ) when ( a ) will be A ( cdot ) з250 ( stackrel{circ}{A} ) B. ( 6.5 times 10^{-4} ) c. 1.3 micron D. ( 2.6 times 10^{-4} ) |
12 |

872 | In a Young’s double slit experiment, the fringes are displaced by a distance ( x ) when a glass plate of refractive index 1.5 is introduced in the path of one of the beams. Then this plate is replaced by another plate of the same thickness, the shift of fringes is ( frac{3}{2} x . ) The refractive index of the second plate is : A . 2.25 в. 2.0 c. 1.75 D. 1.25 |
12 |

873 | The young’s duble slit experiment is performed with blue and green light of wavelength ( 4360 AA ) and ( 5460 dot{A} ) respectively. if ( x ) is the distance of ( 4 t h ) maxima from central one, then A. ( x(b l u e)=x(g text { reen }) ) в. ( x(b l u e)>x(text { green }) ) c. ( x(b l u e)<x(text { gree } n) ) D. ( frac{x(b l u e)}{x(g r e e n)}=frac{5460}{4360} ) |
12 |

874 | Microwaves from a transmitter are directed normally toward a plane reflector. A detector moves along the normal to the reflector. Between positions of 14 successive maxima the detector travels a distance 0.14 m. The frequency of the transmitter is ( (c= ) ( 3 times 10^{8} m s^{-1} ) A. ( 1.5 times 10^{10} mathrm{Hz} ) в. ( 10^{10} mathrm{Hz} ) c. ( 3 times 10^{10} H z ) D. ( 6 times 10^{10} mathrm{Hz} ) |
12 |

875 | Sound waves are passing through two routes-one in straight path and the other along a semicircular path of radius ( r ) and are again combined into one pipe and superposed as shown in the figure. If the velocity of sound waves in the pipe is ( v, ) then frequencies of resultant waves of maximum amplitude will be integral multiples of: ( A ) в. ( frac{v}{r(pi-1)} ) c. ( frac{2 v}{r(pi-1)} ) D. ( frac{v}{r(pi+1)} ) |
12 |

876 | A wave travelling in air falls on a glass plate, It is partly reflected and partly refracted. The phase difference between the reflected and refracted waves is A. zero в. ( frac{pi}{2} ) ( c ) D. ( 2 pi ) |
12 |

877 | The size of corpuscles are for different colours. A. same B. different c. either (a) or (b) D. None of these |
12 |

878 | Two stereo speakers are separated by a distance of ( 2.4 mathrm{m} . ) A person stands at a distance of ( 3.2 mathrm{m} ) as shown directly in front of one of the speakers. Find the frequencies in audible range for which the listener will hear a minimum sound intensity: Speed of the sound in air is ( 320 m s^{-1} ) |
12 |

879 | The oil layer on the surface of water appears coloured, due to interference. For this effect to be visible the thickness of oil layers will be A . ( 1 m m ) B. ( 1 c m ) c. ( 100 A^{circ} ) D. ( 1000 A^{circ} ) |
12 |

880 | A source ( S ) is kept directly behind the slit ( S, ) in a double-slit apparatus. Find the phase difference at a point ( O w h i c h ) is equidistant from ( s 18 ) s2 What will be the phase difference at ( P ) if a liquid of refraction index ( mu ) is filled. (wavelength of light in air is / due to the source) ( (lambda<<d, d<>d) ) A. between the screen and the slits B. between the slits ( & ) the source S. In this case find the minimum distance between the points on the screer where the intensity is half the maximum intensity on the screen c. Beyond the slits D. None of these |
12 |

881 | In a double-slit experiment, the distance between the two slits is 1 m ( m ) and the screen is placed ( 1 m ) away. What should be the width of each slit to obtain 20 maxima of double slit pattern within the central maximum of the single slit pattern? A . ( 0.05 mathrm{cm} ) B. ( 0.02 mathrm{cm} ) c. ( 0.01 mathrm{cm} ) D. ( 0.08 mathrm{cm} ) |
12 |

882 | With what type of source of light are cylindrical wave fronts associated? | 12 |

883 | The distance of ( n^{t h} ) bright band on the screen from the central bright band on either sides of central bright band is A ( cdot x_{n}=frac{n lambda D}{d} ) B・ ( _{x_{n}}=(2 n-1) frac{lambda D}{d} ) c. ( _{x_{n}}=frac{n lambda d}{D} ) D. ( x_{n}=(2 n-1) frac{lambda D}{2 d} ) |
12 |

884 | Light of wavelength ( 5880 A^{circ} ) is incidents on a thin glass plate ( (mu=1.5) ) such that the angle of refraction in the plate is ( 60^{0} ). The minimum thickness of the plate, so that it appears dark in the reflected light will be A ( .3920 A^{circ} ) ( ^{circ} ) B. ( 4372 A^{circ} ) ( c .5840 A^{circ} ) D. ( 6312 A^{circ} ) |
12 |

885 | The maximum number of possible interference maxima for slit separation equal to twice the wavelength in Young’s double slit experiment is : A . infinite B. five c. three D. zero |
12 |

886 | An unpolarised beam of intensity ( boldsymbol{I}_{mathbf{0}} ) falls on a polaroid at an angle of ( 45^{0} . ) The intensity of the emergent light is A ( cdot frac{I_{0}}{2} ) в. ( I_{0} ) c. ( frac{I_{0}}{4} ) D. zero |
12 |

887 | In a modified ( Y D S ) the two slits ( S_{3} ) and ( S_{4} ) are placed in front of the slits ( S_{1} ) and ( S_{2}, ) calculate the ratio of ( m a x^{m} ) intensity to minimum intensity produced in the screen if |
12 |

888 | Consider the arrangement shown in figure (17-E4). The distance ( D ) is large compared to the separation ( d ) between the slits (a) Find the minimum value of ( d ) so that there is a dark fringe at ( O .(b) ) Suppose ( d ) has this value. Find the distance ( x ) at which the bright fringe is formed. (c) Find the fringe-width. |
12 |

889 | 14. Due to interference L P Screen between direct and reflected light from mirror, maxima is Mirror formed at point P. By what minimum distance mirror is shifted downward to find minima at point P. (Assume that, wavelength of light is 600 mm) (a) 100 nm (b) 200 nm (c) 300 nm (d) 400 nm |
12 |

890 | A thin slice is cut out of a glass cylinder along a plane parallel to its axis. The slice is placed on a flat glass plae as shown in figure. The observed interference fringes from this combination shall be A. straight B. circular c. equally spaced D. having fringe spacing which increases as we go outward |
12 |

891 | Figure shows two coherent sources ( S_{1} ) and ( S_{2} ) emitting wavelength ( lambda ). The separation ( S_{1} S_{2}=1.5 lambda ) and ( S_{1} ) is ahead in phase by ( pi / 2 ) relative ( S_{2} ). Then the maxima occur in direction ( theta ) given by ( sin ^{-1} ) of ( (i) 0 ;(i i) 1 / 2 ;(i i i)-1 / 6 ;(i v)-5 / 6 ) Correct options are: A. ( (i i),(i i i),(i v) ) B. (i),( ( (i i),(i i i) ) c. ( (i),(i i i),(i v) ) D. all of the above |
12 |

892 | When the angle of incidence on a material is ( 60^{circ} ), the reflected light is completely polarised. The velocity of the refracted ray inside the material is A . ( 3 times 10^{8} ) B. ( frac{3}{sqrt{2}} times 10^{8} ) c. ( sqrt{3} times 10^{8} ) D. ( 0.5 times 10^{8} ) |
12 |

893 | 61. A plane wave of monochromatic light falls normally on a uniform thin film of oil which covers a glass plate. The wavelength of source can be varied continuously. Complete destructive interference is observed for a = 5000 Å and 1 = 1000 Å and for no other wavelength in between. If u of oil is 1.3 and that of glass is 1.5, the thickness of the film will be (a) 6.738 x10 cm (b) 5.7 x 10 cm (c) 4 x 10 cm (d) 2.8 x 10 cm |
12 |

894 | Amplitudes of two light waves of the same frequency are in the ratio 4: 3 What will be the ratio of maximum and minimum intensities if the two wave interfere? |
12 |

895 | Match the following: Column I A. ( mu=tan i_{p} ) P. Snell’s law B. ( mu=frac{1}{sin i_{c}} ) Q. Brewster’s law C. ( mu=frac{sin i}{sin r} ) R. Prism D. ( mu= ) ( frac{sin left(frac{A+D_{m}}{2}right)}{sin frac{A}{2}} begin{array}{l}text { S. Total internal } \ text { reflection }end{array} ) |
12 |

896 | What is the shape of the wavefront in each of the following cases: (a) Light diverging from a point source. (b) Light emerging out of a convex lens when a point source is placed at its focus.(c) The portion of the wavefront of light from a distant star intercepted by the Earth. |
12 |

897 | A light wave can travel This question has multiple correct options A. In vacuum B. In vacuum only C . In a material medium D. In a material medium only |
12 |

898 | The condition for constructive interference is path difference should be equal to : A. odd integral multiple of wavelength B. Integral multiple of wavelength c. odd integral multiple of half wavelength D. Integral multiple of half wavelength |
12 |

899 | Light is incident at an angle ( phi ) with the normal to a plane containing two slits of separation ( d . ) Select the expression that correctly describes the positions of the interference maxima in terms of the incoming angle ( phi ) and outgoing angle ( theta ) ( ^{mathbf{A}} cdot sin phi+sin theta=left(m+frac{1}{2}right) frac{lambda}{d} ) ( mathbf{B} cdot d sin theta=m lambda ) ( mathrm{c} cdot sin phi-sin theta=(m+1) frac{lambda}{d} ) ” ( sin phi+sin theta=m frac{lambda}{d} ) |
12 |

900 | In a biprism experiment, the distance of 20 th bright bandfrom the center of the interference pattern is ( 8 mathrm{mm} . ) The distance of 30 th bright band from the center is A . ( 11.8 mathrm{mm} ) B. 12mm c. ( 14 mathrm{mm} ) D. ( 16 mathrm{mm} ) |
12 |

901 | The intensity of the central maximum in Youngs double-slit experiment is ( 4 I ) The intensity at the first minimum is zero and the distance between two consecutive maxima is ( boldsymbol{w} ). The distance from the central maximum to the position where the intensity falls to ( I ) is A ( frac{2}{3} omega ) в. ( frac{1}{4} omega ) c. ( frac{1}{2} omega ) D. ( frac{1}{3} ) |
12 |

902 | In Young’s double slit experiment, the two slits act as coherent sources of equal amplitude ‘a’ and of wavelength ( lambda ) In another experiment with the same set up, the two slits are sources of equal amplitude ‘a’ and wavelength ( lambda ), but have ( 90^{circ} ) phase difference. The ratio of intensity of light at the midpoint of the screen in the first case to that in the second case is ( mathbf{A} cdot 2: 1 ) B. 1: 2 c. 3: 4 D. 4: 3 |
12 |

903 | A ray of light from denser medium strikes a rarer medium at an angle of incidence i. The reflected and refracted rays make an angle of ( 90^{circ} ) with each other. Angle of reflection and refraction are r ( & r^{1} . ) The critical angle is a) ( sin ^{-1}(tan r) ) b) ( sin ^{-1}(cot r) ) c) ( sin ^{-1}left(tan r^{1}right) ) d) ( sin ^{-1}left(cot r^{1}right) ) A. only a is correct B. only b is correct c. a and b are correct D. a and d are correct |
12 |

904 | Determine the width of the region where the fringes will be visible ( A cdot 4 c m ) B. ( 6 mathrm{cm} ) ( c .2 c m ) D. 3 cm |
12 |

905 | The thinnest bubble film in air that can possibly strongly reflect red light because of constructive interference makes up a certain bubble. How could we create the thinnest bubble film that will strongly reflect purple light? A. Use a thicker film than the film used for the “red” bubble B. Use a film with a higher index of refraction than the film used for the “red” bubble C. Make a bubble larger than the “red” bubble D. Make a bubble smaller than the “red” bubble E. Use a thinner film than the film used for the “red” bubble |
12 |

906 | Huygen’s originally thought that for the propagation of light waves wavefront is required. A. True B. False |
12 |

907 | The wave nature of the electron was verified using A. Photo electric effect B. Compton effect c. The phenomenon of X-ray emission D. Diffraction of electron by a crystal |
12 |

908 | Use the mirror equation to show that an object placed between ( f ) and ( 2 f ) of ( a ) concave mirror produces a real image beyond ( 2 f ) OR Find an expression for intensity of transmitted light when a polaroid sheet is rotated between two crossed polaroids. In which position of the polaroid sheet will the transmitted intensity be maximum? |
12 |

909 | At the angle of polarisation, the angle of inclination between the reflected and refracted rays is ( A cdot frac{pi}{8} ) в. ( frac{pi}{6} ) ( c cdot frac{pi}{4} ) 0.5 |
12 |

910 | How will you identify with the help of an experiment whether a given beam of light is of polarized light or of unplolarised light? | 12 |

911 | slit separation dis ( 0.3 mathrm{mm} ) and the screen distance D is 1 m. A paralle beam of light of wavelength 600 nm is incident on the slits at angle ( alpha ) as shown in figure. On the screen, the point O is equidistant from the slits and distance PO is ( 11.0 mathrm{mm} ). Which of the following statement (s) is/are correct? A. For ( alpha=0 ), there will be constructive interference at point P. B. For ( alpha=frac{0.36}{pi} ) degree, there will be destructive interference at point P. C ( cdot_{text {Fro } alpha}=frac{0.36}{pi} ) degree, there will be destructive interference at point 0 D. Fringe spacing depends |
12 |

912 | If the incidence is at polarising angle, the angle between Reflected ray and the Refracted ray from a surface is |
12 |

913 | A travelling acoustic wave frequency ( 500 H z ) is moving along the positive ( x ) direction with a velocity of ( 300 m s^{-1} ) The phase difference between two points ( x_{1} ) and ( x_{2} ) is ( 60^{circ} . ) Then the minimum separation between the two points is: ( mathbf{A} cdot 1 m m ) в. ( 1 mathrm{cm} ) ( c cdot 10 mathrm{cm} ) D. ( 10 mathrm{mm} ) |
12 |

914 | incident on a coated glass plate. If ( 25 % ) of the incident light is reflected from the upper surface and ( 50 % ) of light is reflected from the lower surface of the glass plate, the ratio of maximum to minimum intensity in the interference region of the reflected light is ( A ) B. ( c cdot frac{5}{8} ) ( D cdot 8 ) ( overline{5} ) |
12 |

915 | Unpolarized light of intensity ( I ) is incident on a system of two polarizes, ( A ) followed by ( B ). The intensity of emergent light is ( I / 2 . ) If a third polarizer ( C ) is placed between ( A ) and ( B ), the intensity of emergent light is reduced to ( I / 3 . ) The angle between the polarizers ( A ) and ( C ) is ( theta . ) Then ( ^{mathrm{A}} cdot cos theta=left(frac{2}{3}right)^{1 / 4} ) в. ( cos theta=left(frac{1}{3}right)^{1 / 4} ) ( ^{mathrm{c}} cos theta=left(frac{1}{3}right)^{1 / 2} ) Des ( theta=left(frac{2}{3}right)^{1 / 2} ) |
12 |

916 | The y-coordinate of second order bright (maxima) formed on the screen is A ( .250 mu m ) B. ( 500 mu m ) ( mathbf{c} .-250 mu m ) ( mathbf{D} cdot-500 mu m ) |
12 |

917 | Light travels as a A. parallel beam in each medium B. convergent beam in each medium C. divergent beam in each medium D. divergent beam in one medium and convergent beam in the other medium |
12 |

918 | In Young’s double-slit experiment the spacing between the slits is ‘d and wavelength of light used is 6000 A. If the angular width of a fringe formed on a distant screen is ( 1^{0}, ) then value ( ^{prime} d^{prime} ) is : A . ( 1 m m ) B. ( 0.05 mathrm{mm} ) c. ( 0.03 m m ) D. ( 0.01 m m ) |
12 |

919 | The parallel rays of white light are made an incident normally on an air film of uniform thickness. 250 fringes are seen in the transmitted light between ( 4000 A^{circ} ) and ( 6500 A^{circ} . ) Thickness of air film is A . ( 1.3 m m ) в. ( 1.5 mathrm{mm} ) c. ( 0.13 m m ) D. ( 0.11 m m ) |
12 |

920 | The refractive index of a certain flint glass is ( 1.65 . ) Incident angle is the light reflected from the surface of the glass completely polarized if the glass is immersed in (a) air and (b) water is ( left(tan 58.8^{circ}=1.65right)left(tan 51.1^{circ}=1.24right) ) A. ( 60^{circ}, 50^{circ} ) B. 58.8′, 51.1 ( ^{circ} ) ( c cdot 65^{circ}, 52^{circ} ) D. ( 61^{circ}, 54^{circ} ) |
12 |

921 | The intensity of sound reduces by ( 20 % ) on passing through a glass slab. If sound of intensity 1 is made to cross through two such slabs, then the intensity of emergent sound will be A. 36 % B. 64% c. ( 40 % ) D. 80% |
12 |

922 | The phase difference between two waves from successive half period zones or strips is : A ( cdot frac{pi}{4} ) в. ( frac{pi}{2} ) ( c . pi ) D. zero |
12 |

923 | When two waves of almost equal frequency ( n_{1} ) and ( n_{2} ) are produced simultaneously, then the times interval between successive maxima is A ( cdot frac{1}{n_{1}+n_{2}} ) в. ( frac{1}{n_{1}}+frac{1}{n_{2}} ) c. ( frac{1}{n_{1}}-frac{1}{n_{2}} ) D. ( frac{1}{n_{1}-n_{2}} ) |
12 |

924 | Two independent monochromatic sodium lamps can not produce interference because A. The frequencies of the two sources are different B. The phase difference between the two sources changes will respect to time. c. The two sources become coherent. D. The amplitude of two sources is different |
12 |

925 | Two coherent light sources ( S_{1} ) and ( boldsymbol{S}_{2}(boldsymbol{lambda}=mathbf{6 0 0 0} boldsymbol{A}) ) are 1 mm apart from each other. The screen is placed at a distance of ( 25 mathrm{cm} ) from the sources. The width of the fringes on the screen should be A. ( 0.015 mathrm{cm} ) В. ( 0.013 mathrm{cm} ) c. ( 0.01 mathrm{cm} ) D. ( 0.10 mathrm{cm} ) |
12 |

926 | The width of one of the two slits in Young’s double slit experiment is double of the other slit. Assuming that the amplitude of the light coming from a slit is proportional to the slit width. Find the ratio of the maximum to the minimum intensity in the interference pattern |
12 |

927 | At what maximum width ( delta_{max }, ) of the slit are the interference fringes on the screen observed still sharp? ( mathbf{A} cdot 42 mu m ) B. ( 36 mu m ) ( mathrm{c} .64 mu mathrm{m} ) D. none of these |
12 |

928 | Bartholinus discovered: A. Interference by splitting the wave front B. Polarisation by reflection C. Polarisation by refraction D. Polarisation by double refraction |
12 |

929 | Who first proposed that the light exhibits wave nature and explained wave phenomenon? A. Max Planck B. James Clerk Maxwell c. Isaac Newton D. Christian Huygens |
12 |

930 | The bending of light about corners of an obstacle is called: A. Dispersion B. Refraction c. Deviation D. Diffraction |
12 |

931 | Let a beam of wavelength ( lambda ) fall on parallel reflecting planes with separation ( d ), then the angle ( theta ) that the beam should make with the planes so that reflected beams from successive planes may interfere constructive should be (where, ( boldsymbol{n}=mathbf{1}, mathbf{2}, dots . .) ) ( ^{text {A }} cdot cos ^{-1}left(frac{n lambda}{2 d}right) ) B ( cdot sin ^{-1}left(frac{n lambda}{2 d}right) ) ( ^{mathbf{c}} cdot sin ^{-1}left(frac{n lambda}{d}right) ) D. ( tan ^{-1}left(frac{n lambda}{d}right) ) |
12 |

932 | The waveforms of a light wave traveling in vacuum are given by ( boldsymbol{x}+boldsymbol{y}+boldsymbol{z}=boldsymbol{c} ) The angle made by the direction of propagation of light with the ( X ) -axis is A ( cdot 0^{circ} ) B ( cdot 45^{circ} ) ( c cdot 90^{circ} ) D. ( cos ^{-1} frac{1}{sqrt{3}} ) |
12 |

933 | State clearly how an unpolarised light gets linearly polarised when passed through a polaroid. (i) Unpolarised light of intensity ( I_{0} ) is incident on a polaroid ( P_{1} ) which is kept near another polaroid ( P_{2} ) whose pass axis is parallel to that of ( boldsymbol{P}_{1} ). How will the intensities of light, ( boldsymbol{I}_{1} ) and ( boldsymbol{I}_{2} ) transmitted by the polaroids ( P_{1} ) and ( P_{2} ) respectively, change on rotating ( boldsymbol{P}_{1} ) without disturbing ( P_{2} ? ) (ii) Write the relation between the intensities ( I_{2} ) and ( I_{1} ) |
12 |

934 | Unpolarised light of intensity I passes through an ideal polarizer A. Another identical polarizer B is placed behind A. The intensity of light beyond B is found to be ( frac{1}{2} . ) Now another identical polarizer ( mathrm{C} ) is placed between ( mathrm{A} ) and ( mathrm{B} ). The intensity beyond B is now found to be ( frac{1}{8} ) The angle between polarizer A and C is? A ( cdot 45^{circ} ) B. ( 60^{circ} ) ( c cdot 0^{circ} ) D. ( 30^{circ} ) |
12 |

935 | To reduce the light reflected by the glass surface of a camera lens, the surface is coated with a thin layer of another material which has an index of refraction ( (mu=7 / 4) ) smaller than that of glass. The least thickness of the layer to ensure that light falling perpendicularly on the surface and having wavelengths, ( lambda_{1}=700 mathrm{nm} ) and ( lambda_{2} ) ( =420 mathrm{nm} ) will be weekly reflected for both wavelengths is ( 10^{-7} mathrm{m} ). Find ( x ) ? |
12 |

936 | The path difference produced by two waves is ( 3.75 mu m ) and the wavelength is ( mathbf{5 0 0 0} boldsymbol{A} . ) The point is A. Uncertain B. Dark c. Partially bright D. Bright |
12 |

937 | State any one difference between interference of light and diffraction of light. |
12 |

938 | In a single slit diffraction with ( lambda= ) ( 500 n m ) and a lens of diameter ( 0.1 mathrm{mm} ) width of central maxima, obtain on screen at a distance of ( 1 mathrm{m} ) will be ( mathbf{A} cdot 5 m m ) B. ( 1 mathrm{mm} ) ( mathrm{c} .10 mathrm{mm} ) D. ( 2.5 m m ) |
12 |

939 | 71. In Young’s double-slit experiment using monochroma light, the light pattern shifts by a certain distans the screen when a mica sheet of refractive indexu thickness t microns is introduced in the path of one of the interfering waves. The mica sheet is then removed and the distance between the plane of slits and the screen i doubled. It is found that the distance between successive maxima (or minima) now is the same as the observed fringe shift upon the introduction of the mica sheet Calculate the wavelength of light? (a) (1/2)t (u – 1) (b) t (u – 1) (c) ut (d) 3ut |
12 |

940 | Unpolarized light of intensity ( boldsymbol{I}_{mathbf{0}} ) is incident on a polarizer and the emerging light strikes a second polarizing filter with its axis at ( 45^{circ} ) to that of the first. The intensity of the emerging beam: A ( cdot frac{I o}{2} ) в. ( frac{text { Io }}{4} ) ( c cdot I_{o} ) D. ( frac{text { Io }}{3} ) |
12 |

941 | The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index ( n ) ) is A ( cdot sin ^{-1}(n) ) B. ( sin ^{-1}left(frac{1}{n}right) ) ( ^{mathbf{c}} cdot tan ^{-1}left(frac{1}{n}right) ) ( mathbf{D} cdot tan ^{-1}(n) ) |
12 |

942 | Assertion Diffraction takes place for all types of waves mechanical or non-mechanical, transverse or longitudinal. Reason Diffraction’s effect are perceptible only if wavelength of wave is comparable to dimensions of diffracting device. A. Both Assertion are not correct and Reason is the correct B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect;Reason is not correct explanation for Assertion D. Both Assertion is correct and Reason are incorrect |
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943 | Assertion: The clouds in sky generally appear to be whitish.
Reason: Diffraction due to clouds is |
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944 | A microscope is used with sodium light and its resolving power is not sufficiently large.Higher resolution will be obtained by using wavelength of A. 20 micron B. 2 micron c. 1 micron D. ( 400 mathrm{A}^{circ} ) |
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945 | Indentify the correct statement from the following This question has multiple correct options A. Wave nature of light was proposed by Huygen. B. The direction of light ray and its wave front are opposite. C. Huygen’s wave theory could not explain phenomenon of reflection. D. A monochromatic ray of light after passing through the prism should be made of one colour only. |
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946 | In a diffraction(single slit experiment), the slit is exposed by white light. The fringe surrounding the central fringe is A. Red B. Yellow c. violet D. Green |
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947 | To ensure almost 100 per cent transmittivity, photographic lenses are often coated with a thin layer of dielectric material. The refractive index of this material is intermediated between that of air and glass (which makes the optical element of the lens) A typically used dielectric film is ( M g F_{2} ) ( (n=1.38) . ) What should the thickness of the film be so that at the center of the visible spectrum ( (5500 A) ) there is maximum transmission. A ( cdot 5000 ) a в. 2000 А c. 1000 a D. 3000 , |
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948 | When waves of same intensity from two coherent sources reach a point with zero path different the resulting intensity is ( mathrm{K} ). When the above path difference is ( lambda / 4 ) the intensity becomes ( A cdot K ) B. K/2 ( c cdot k / 4 ) D. K/8 |
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949 | When an unpolarised light is polarized, then the intensity of light of the polarized wave : A. remains the same B. gets doubled c. gets halved D. depends on the colour of the light. |
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