MCQ Geomtric AND Optics PDF

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Physics MCQs for Class 12 with Answers Chapter 10 Wave Optics by Veerendra Free PDF Download of CBSE Physics Multiple Choice Questions for Class 12 with Answers Chapter 10 Wave Optics. Physics MCQs for Class 12 Chapter Wise with Answers PDF Download was Prepared Based on Latest Exam Pattern. Students can solve NCERT Class 12 Physics Wave Optics MCQs Pdf with Answers to know their preparation level.

Wave Optics Class 12 Physics MCQs Pdf MCQ on Wave Optics Class 12 Question 1. Resolving power of telescope can be increased by increasing (a) the wavelength (b) the diameter of objective (c) the diameter of eyepiece (d) the focal length of eyepiece Answer/Explanation Answer: b Explaination: (b) The diameter of objective as R.P. of a telescope = D1.22λ R.P. is proportional 1.22 A to diameter of objective (D).

Wave Optics MCQ Question 2. Polarisation of light proves (a) corpuscular nature of light. (b) quantum nature of light. (c) transverse wave nature of light. (d) longitudinal wave nature of light. Answer/Explanation Answer: c Explaination: (c) transverse wave nature of light.

Wave Optics Class 12 MCQ Question 3. The wavefront due to a source situated at infinity is (a) spherical (b) cylindrical (c) planar (d) circular Answer/Explanation

Answer: c Explaination: (c) The wavefront due to any source situated at infinity is planar.

4. A laser beam is coherent because it contains (р) waves of several wavelengths. (b) incoherent waves of a single wavelength. (c) coherent waves of several wavelengths (d) coherent waves of a single wavelength. Answer/Explanation Answer: d Explaination: (d) coherent waves of a single wavelength.

MCQ on Wave Optics Pdf Question 5. If two sources have a randomly varying phase difference Φ(t), the resultant intensity will be given by

Answer/Explanation Answer: c Explaination: (c) 2I0, For two incoherent sources, the resultant intensity at every point is just twice of the two individual intensities.

6. According to Huygens’ principle, light is a form of (a) particle (b) rays (c) wave (d) radiation Answer/Explanation Answer: c Explaination: (c) According to Huygens’ principle, light travels in the form of a longitudinal wave.

Optics MCQ 14 Question 7. Two coherent monochromatic light beams of intensities I and 41 superimpose. The maximum and minimum possible intensities in the resulting beam are: (a) 5I and I

(b) 5I and 3I (c) 3I and I (d) 9I and I Answer/Explanation Answer: d Explaination:

Wave Optics Questions with Answers Pdf Question 8. What is path difference for destructive interference? (a) nλ (b) n(λ +1) (c) (2n + 1)λ2 (d) (n +1)λ2 Answer/Explanation Answer: c Explaination: (c) (2n + 1)λ2 For destructive interference, the path difference is an odd multiple of λ/2.

9. When exposed to sunlight, thin films of oil on water of ten exhibit brilliant colours due to the phenomenon of (a) interference (b) diffraction (c) dispersion (d) polarisation Answer/Explanation Answer: a Explaination: (a) interference

10. What happens, if the monochromatic light used in Young’s double slit experiment is replaced by white light? (a) No fringes are observed. (b) All bright fringes become while. (c) All bright fringes have colour between violet and red.

(d) Only the central fringe is white and all other fringes are coloured. Answer/Explanation Answer: d Explaination: (d) At central bright fringes of all wavelength overlap to produce white central fringe.

11. When compact disk is illuminated by a source of white light, coloured lines are observed. This is due to (a) dispersion (b) diffraction (c) interference (d) refraction Answer/Explanation Answer: b Explaination: (b) The small ripples on the compact disc split white light into the constituent colours.

12. An unpolarised beam of intensity I0 is incident on a pair of nicols making angle of 60° with each other. The intensity of right emerging from the pair is

Answer/Explanation Answer: d Explaination:

13. When unpolarised light beam is incident from air onto glass (n = 1.5) at the polarising angle. (a) Reflected beam is polarised completely (b) Reflected and refracted beams are partially polarised (c) Refracted beam is plane polarised (d) Whole beam of light is refracted Answer/Explanation Answer: b Explaination: (b) The reflected fight is completely polarised.

14. Resolving power of microscope depends upon (a) wavelength of light used (directly proportional) (b) wavelength of light used (inversely proportional) (c) frequency of light used (d) focal length of objective Answer/Explanation Answer: b Explaination:

15. The phenomenon of interference is based on (a) conservation of momentum. (b) conservation of energy. (c) conservation of momentum and energy. (d) quantum nature of light. Answer/Explanation Answer: b Explaination: (b) conservation of energy

16. A double slit interference experiment is carried out in air and the entire arrangement is dipped in water. The fringe width (a) increases (b) decreases (c) remains unchanged. (d) fringe pattern disappears. Answer/Explanation Answer: b Explaination: (b) Decreases

17. In Young’s double slit experiment, if the monochromatic source of yellow light is replaced by

red light, the fringe width (a) increases (b) decreases. (c) remains unchanged. (d) the fringes disappear Answer/Explanation Answer: a Explaination: (a) Increases, as fringe width β ∝ λ(λyellow < λed)

18. In Young’s double-slit experiment, the intensity at the central maximum is I0 if one of the slit is covered, then the intensity at the central maximum become:

Answer/Explanation Answer: c Explaination:

19. The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index n) is

Answer/Explanation Answer: d Explaination: (d) Polarising angle, i = tan-1 (n), (Brewster’s law)

20. In Young’s double-slit experiment, the intensity is I at a point, where the path difference is λ6 (λ – wavelength of light used). If I0 denotes the maximum intensity then II0 is equal to

Answer/Explanation Answer: c Explaination: (c) As path difference,

21. The idea of secondary wavelets for the. propagation of a wave was first given by (a) Newton (b) Huygens (c) Maxwell (d) Fresnel Answer Answer: b

22. Light propagates rectilinearly, due to (a) wave nature (b) wavelengths (c) velocity (d) frequency Answer Answer: a

23. Which of the following is correct for light diverging from a point source? (a) The intensity decreases in proportion with the distance squared. (b) The wavefront is parabolic.

(c) The intensity at the wavelength does not depend on the distance. (d) None of these. Answer Answer: a

24. The refractive index of glass is 1.5 for light waves of X = 6000 A in vacuum. Its wavelength in glass is (a) 2000 Å (b) 4000 Å (c) 1000 Å (d) 3000 Å Answer Answer: b

25. The phenomena which is not explained by Huygen’s construction of wavefront (a) reflection (b) diffraction (c) refraction (d) origin of spectra Answer Answer: d

26. A laser beam is used for locating distant objects because (a) it is monochromatic (b) it is not chromatic (c) it is not observed (d) it has small angular spread. Answer Answer: d

27. Two slits in Young’s double slit experiment have widths in the ratio 81 :1. The ratio of the amplitudes of light waves is (a) 3 :1 (b) 3 : 2 (c) 9 :1 (d) 6:1 Answer

Answer: c

28. When interference of light takes place (a) energy is created in the region of maximum intensity (b) energy is destroyed in the region of maximum intensity (c) conservation of energy holds good and energy is redistributed (d) conservation of energy does not hold good Answer Answer: c

29. In a double slit interference pattern, the first maxima for infrared light would be (a) at the same place as the first maxima for green light (b) closer to the centre than the first maxima for green light (c) farther from the centre than the first maxima for green light (d) infrared light does not produce an interference pattern Answer Answer: c

30. To observe diffraction, the size of the obstacle (a) should beX/2, where X 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. Answer Answer: b

31. The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 A is of the order of (a) 106 rad (b) 10-2 rad (c) 10-4 rad (d) 10-6 rad Answer Answer: d

32. The velocity of light in air is 3 * 108 ms-1 and that in water is 2.2 * 108 ms” . The polarising

angle of incidence is (a) 45° (b) 50° (c) 53.74° (d) 63 Answer Answer: c

33. An optically active compound (a) rotates the plane of polarised light (b) changes the direction of polarised light (c) does not allow plane polarised light to pass through (d) none of these Answer Answer: a

34. 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 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. [NCERT Exemplar] Answer Answer: c

35. Consider sunlight incident on a slit of width 104 A. The image seen through the slit shall (a) be a fine sharp slit white in colour at the centre.

(b) a bright slit white at the centre diffusing to zero intensities at the edges. (c) a bright slit white at the centre diffusing to regions of different colours. (d) only be a diffused slit white in colour. [NCERT Exemplar] Answer Answer: a

36. In a Young’s double slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case (a) there shall be alternate interference patterns of red and blue. (b) there shall be an interference pattern for red distinct from that for blue. (c) there shall be no interference fringes. (d) there shall be an interference pattern for red mixing with one for blue. [NCERT Exemplar] Answer Answer: c

37. Figure shows a standard two slit arrangement with slits S1 S2. P1 P2 are the two minima points on either side of P (Figure). At P2 on the screen, there is a hole and behind P2 is a second 2- slit arrangement with slits S3, S4 and a second screen behind them. [NCERT Exemplar]

(a) There would be no interference pattern on the second screen but it would be lighted. (b) The second screen would be totally dark. (c) There would be a single bright point on the second screen. (d) There would be a regular two slit pattern on the second screen. Answer Answer: d

38. Consider the diffraction pattern for a small pinhole. As the size of the hole is increased (a) the size decreases.

(b) the intensity decreases. (c) the size increases. (d) the intensity decreases. [NCERT Exemplar] Answer Answer: a

39. For light diverging from a point source (a) the wavefront is spherical. (b) the intensity increases in proportion to the distance squared. (c) the wavefront is parabolic. (d) the intensity at the wavefront does not depend on the distance. Answer Answer: a...