Q. No. 1 Newton postulated his corpuscular theory of light on the basis of

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1 Q. No. 1 Newton postulate his corpuscular theory of light on the basis of Newton s rings Option Rectilinear propagation of light Colour through thin films Dispersion of white light into colours. Correct Answer Rectilinear propagation of light Q. No. In Huygen s wave theory, the loucs of all points in the same state of vibrations is calle A half perio zone Option A wavefront A ray Vibrator Correct Answer A wavefront Q. No. 3 Huygen s concept of seconary wave Allows us to fin the focal length of a thick lens Option Is a geometrical metho to fin a wavefront Is use to etermine the velocity of light Is use to explain polarisation Correct Answer Is a geometrical metho to fin a wavefront Q. No. 4 Light waves are Electromagnetic waves in nature Option Cosmic rays Infra re rays Invisible in atmosphere Electromagnetic waves in nature Q. No. 5 The electromagnetic waves travel with a velocity Equal to the velocity of soun Option Equal to the velocity of light Less than the velocity of light Greater than the velocity of light Correct Answer Equal to the velocity of light Q. No. 6 Maxwell s electromagnetic theory of light suggests that the light consists of oscillation of Magnetic vector alone Option Electric vector alone Electric an magnetic vectors perpenicular to each other Parallel electric an magnetic vectors Electric an magnetic vectors perpenicular to each other

2 Q. No. 7 Quantum nature of light is not supporte by the phenomenon of Compton effect Option Photoelectric effect Emission or absorption spectrum inter Interference of light Interference of light Q. No. 8 Though quantum theory of light can explain a number of phenomenon observe with light, it is necessary to retain the wave nature of light of explain the phenomenon of Photoelectric effect Option Diffraction Compton effect Black boy raiation Correct Answer Diffraction Q. No. 9 In young s ouble slit experiment, the interference pattern is foun to have an intensity ratio between bright an ark fringes, as 9. This implies that The intensities at the screen ue to the two slits are 5 units an 4 units respectively Option The intensities at the screen ue to the two slits are 4 units an 1 units respectively The amplitue ratio is 3 The amplitue ratio is IB Intensity of bright fringe 9 I Intensity of ark fringe 1 D Two slits of I 1 an I I + I 9 I + I 3 1 I I I1 I 1 I1 +1 I 3 I1 I I1 1 I I 1 I I1 4 I1 I 1 I 1 I 1 4 A ani A 1 I 1 A 1 Q. No. 1 In young s ouble slit experiment, the separation between the slit is halve an the istance between the slits an screen is ouble. The fringe with is Unchange Option Halve Double Quaruple

3 Fringe with D D D 4 / Q. No. 11 In young s experiment the wavelength of re light is cm an that of blue light 5. 1 cm. The value of n for which (n + 1)th blue bright ban coincies with n th re ban is 4 Option 3 1 x +1 bd n red y, y x +1 bd n red n 5 Q. No. 1 We shift young s ouble slit experiment from air to water. Assuming that water is still an clear, it can be preicte that the fringe pattern will Remain unchange Option Disappear Shrink Be enlarge D Since fringe with In water, ' M, Hence fringe with, So pattern strinks. Q. No. 13 In young s ouble slit interference experiment, the istance between two sources is.1 mm. The istance of the screen from the sources is cm. Wavelength of light use is 546 A. Then the angular position of the first ark fringe is.8 Option Correct Answer.16 Q. No. 14 The intensity ratio of the two interfering beams of light is. What is the value of I I max min I +I max min Option 1+?

4 1+ 1+ Correct Answer I1 B, I I + I I max 1 I I I min 1 I I I + I I I max min Then 1 1 I +I max min I + I + I I 1 1 I 1. I I 1. I B I + I I 1 1 I+B I +1 I Q. No. 15 In the Young s ouble slit experiment, the two equality bright slits are coherent, but of I Option I phase ifference 3. If the maximum intensity on the screen is I, the intensity at the point on the screen equiistant from the slits is I 4 I 3 4 I R 4Icos (I Intensity of any two equally bright source) max 1 an I I + I I I 1I I (As two same bright coherent sources) I I max I II 4 I So I R4.cos as I 3 3I Q. No. 16 In an interference pattern prouce by two inentical slits, the intensity at the sie of the central maximum is I. The intensity at the same spot when either of the two slits us close is I. Therefore I I Option I I I 4I

5 I an I are not relate to each other. I 1 I I, I min I1 I max I I I I4I Q. No. 17 Two waves of same wavelength an amplitue interfere to give a minimum when phase ifference is Option 3 n 1 When path ifference is an phase ifference n+1 Q. No. 18 In a ouble slit experiment, the first minimum on either sie of the central maximum occurs where the path ifference between the two paths is Option 4 Correct Answer n 1 path ifference (for a minimum) So n 1, (per first minimum) Q. No. 19 Two light rays having the same wavelength in vacumm are in phase initially. Then the first ray travels a path of length L, through a meium of refractive inex n 1 while the secon ray travels a path of length L through a meium of refractive inex n. The two waves are then combine to observe interference. The phase ifference between the two waves is L L 1 Option n L n L 1 1 n L n L 1 1 L L n n 1 1

6 Correct Answer Path ifference optical path of first Ray optical path of secon Ray x x1l1 xl Phase ifference x Q. No. In Young s ouble slit interference experiment if the slit separation is mae 3 fols the fringe with becomes 1 fol 3 Option 3 fol 3 fol 6 6 fol D Fringe with, if 3 Q. No. 1 Two slits separate by a istance of 1 mm are illuminate with re light of wavelength 6.51 m. The interference fringes are observe on a screen place 1 m from the slits. The istance between thir ark fringe an the fifth bright fringe is equal to.65 mm Option 3.5 mm 1.63 mm 4.88 mm Correct Answer Require Distance y 5th maximum y 3r minimum D 5D mm 3 1 Q. No. In a ouble slit interference experiment the istance between the slits is.5 cm an screen is m away from the slits. The wavelength of light is 6. 1 cm. The istance between the fringe is.4 cm Option.1 cm 1.8 cm.1 cm 5 D cm 1.4 cm 5

7 Q. No. 3 Two waves originating from sources S 1 an S having zero phase ifference an common wavelength will show completely estructive interference at a point P if (S 1 P S P) is 5 Option Where path ifference is Put x6 n 1 Q. No. 4 In Young s ouble slit experiment is the slit withs are in the ratio 1 : 9, the ratio of the intensity at minima to that at maxima will be 1 Option Slit withs 1 an 1 1 I I I I 3 I I I I 3 I min I max I + I 3 I + I Q. No. 5 Two waves having the intensities in the ratio of 9 :1 prouce interference. The ratio of maximum to minimum intensity is equal to 1 : 8 Option 9 : 1 4 : 1 : 1 I I + I max 1 an I 1 9 I min I I I 1 I 4 I 1 max min 1 Q. No. 6 Two coherent monochromatic light beams of intensities an 4 I are superpose. The maximum an minimum possible intensities in the resulting beam are 5 I an I

8 Option 5 I an 3 I 9 I an I 9 I an 3 I 9 I an I Q. No. 7 In the Young s ouble slit experiment, the intensity on the screen at a point where path ifference is is K. What will be the intensity at the point where path ifference is 4? K 4 Option K K Zero Correct Answer x x 1 1 An x 4 So, I 4I cos R1 K4I cos I 4I cos R K 4 Q. No. 8 In the Young s ouble slit experiment using soium light 5898A, 9 friges are seen. If given colour 5461A is use, how many fringes will be seen? 6 Option D 1 Fringe with 1 So, y 9 1 D A An 9 x 1

9 Q. No. 9 D D A x 5461A x99 The isplacement of the interfering light waves are y 1 4sint an y 3sin t+ What is the amplitue of resultant wave? 5 Option 7 1 Zero A A RA 1+A +A1Acos A R 5 Q. No. 3 In the two separate set ups of the Young s ouble slit experiment, fringes of equal with are observe when lights of wavelengths in the ratio 1 : are use. If the ratio of the slit separation in the two cases is : 1, the ratio of the istances between the plane of the slits an the screen, in the two set ups in 4 : 1 Option 1 : 1 1 : 4 : 1 D1 1 D 1, 1 D1 1 1 D 4 1 D 1 D Q. No. 31 What is the path ifference for estructive interference? n Option n +1 n+1 n 1 n 1 Q. No. 3 If an interference pattern has maximum an minimum intensities in the ratio of 36 : 1 then what will be the ration of amplitues 5 : 7 Option 7 : 4 4 : 7

10 7 : 5 I I + I max 1 36 I min I I 1 1 A 1+A 6 A A 1 1 A1 7 A 5 As I A Q. No. 33 When viewe in white light, soap bubbles show colours because of Interference Option Scattering iffraction isperscion Interference Q. No. 34 Oil floating on water looks coloure ue to interference of light. The approximate thickness of oil such effect to be visible 1A Option 1,A 1 mm 1 cm Correct Answer Average path ifference will be (if ignore ) Then for interference n Then acc. to option, (light) 9 95 A Q. No. 35 When light wave suffers reflection at the interface between air an glass, the change of phase of the reflecte wave is equal to Zero Option When wave goes from rarer to enser meium, reflecte waves suffers a path ifference of OR phase ifference Q. No. 36 To observe iffraction, the size of an obstacle Shoul be of the same orer as wavelength Option Shoul be much larger than the wavelength Have no relation to wavelength

11 Shoul be exactly Shoul be of the same orer as wavelength Q. No. 37 A iffraction pattern is obtaine using a beam of re light. What happens if the re light is replace by blue light No change Option Diffraction bans become narrower an crowe together Bans becomes broaer an farther apart Bans isappear Correct Answer As asin n, fringe with Q. No. 38 Diffraction an interference inicate Wave nature Option Particle nature Both a an b None of the above Wave nature Q. No. 39 The conition for observing Fraunhofer iffraction from a single slit is that the light wavefront incient on the slit shoul be Spherical Option Cylinrical Plane Elliptical Plane Q. No. 4 The main ifference in the phenomenon of interference an iffraction is that Diffraction is ue to interaction of light from the same wavefront whereas interference is the interaction of waves from two isolate sources Option Diffraction is ue to interaction of light from same wavefront, whereas interference is the interaction of two waves erive from the same source. Diffraction is ue to interaction of waves erive from the same sources, whereas the interference is the bening of light from the same wavefront. Diffraction is cause by reflecte waves from a source whereas interference cause is ue to refraction of waves from a surface. Correct Answer Diffraction is ue to interaction of light from same wavefront, whereas interference is the interaction of two waves erive from the same source.

12 Q. No. 41 The first iffraction minima ue to a single iffraction is at 3 for a light of wavelength 5 A. The with of the slit is 51 cm Option cm.51 cm 1.51 cm Correct Answer asin n, n1 asin3 1 5 A 4 a1 cm Q. No. 4 A slit of with a is illuminate by white light. The first minimum forre light 65A will fall at 3 when a will be 35A Option cm 1.3 micron 4.61 cm asin n, 1 a 65 A 6 13A 1.31 m 1.3 micron Q. No. 43 Light of wavelength is incient on a slit of with. The resulting iffraction pattern is observe on a screen at a istance D. The linear with of the principal maximum is then equal to the with of the slit if D equals Option In case of iffraction, with of principal. (Central maxima) Distance between 1 st minima below an above center point. asin n (for minima) For small y D a n y Above centre 1 D 1 a

13 D an y (below centre) a D So, Total with ad a Q. No. 44 Soun waves o not exhibit Refraction Option Interference Diffraction polarization As longituinal waves, so no polarization. Q. No. 45 Polarisation of light proves the Corpuscular nature of light Option Quantum nature of light Transverse nature of light Longituinal wave nature of light Transverse nature of light Q. No. 46 Light waves can be polarize because they Have high frequencies Option Have short frequencies Are transverse Can be reflecte Are transverse Q. No. 47 Light transmitte by a Nicol crystal is Plane polarize Option Unpolarise Circularly polarize Elliptically polarise Plane polarize Q. No. 48 Polaroi glass is use in sum glasses because It reuces the light intensity to half on account of polarisation Option It is fashionable It has goo colour It is cheaper It reuces the light intensity to half on account of polarisation Q. No. 49 If the light is polarise by reflection, then the angle between reflecte an refracte light is

14 Option 4 Correct Answer In case of polarization, Q. No. 5 A ray light strikes a glass plate at an angle of 6. If the reflecte an refracte rays are perpenicular to each other, the inex of refraction of glass is 3 Option n 1 sin6 n sin n n 3 Q. No. 51 A ray of light is incient on the surface of a glass plate of refractive inex 1.55 at the polarizing angle. The angle of refraction is 57 11' Option 3 49' '

15 Correct Answer sin p sin r p r cosr tan r.66 sin 155 r r 3 49' Q. No. 5 From Brewster s law for polarisation, it follows that the angle of polarisation epens upon The wavelength of light Option Plane of polarisation s orientation Plane of vibration s orientation None of the above The wavelength of light Q. No. 53 A beam of light AO is incient on a glass slab 1.54 in a irection as shown in figure. The reflecte ray OB is passe through a nicol prism on viewing through a Nicol prism, we fin a roatating the prism that Option The intensity is reuce own to zero an remains zero The intensity is reuces own somewhat an rises again There is no change The intensity graually reuces to zero an then again increases. Nicol prism is a polarizer, its plane of polarization rotates, Hence II cos, Intensity changes accoring to this Q. No. 54 Choose the correct statement The Brewster s angle is inepenent of wavelength of light Option The Brewster s angle is inepenent of nature of reflecting surface The Brewster s angle is ifferent for ifferent wavelength Brewster s angle epens on wavelength but not on the nature of reflecting surface. As Refractive inex changes with wavelength, so epens on p

16 Q. No. 55 A ray of light is incient on the surface of a glass plate an angle of incience equal to Brewster s angle. If represents the refractive inex of glass with respect to air, then the angle between reflecte an refracte rays is 9 + Option 1 sin cos sin sin Angle between Reflecte refracte Ray is 9 Q. No. 56 When unpolarise light is incient on a plane glass plate at Brewster s (polarising) angle, then which of the following statements is correct Reflecte an refracte rays are completely polarise with their planes of polarisation parallel to each other. Option Reflecte an refracte rays are completely polarise with their planes of polarisation perpenicular to each other The reflecte light is plane polarise but transmitte light is partially polarise The reflecte light is partially polarise but refracte light is plane polarise.