Tiêu đề 29. Wave optics Easy.pdf ✅

1. By corpuscular theory of light, the phenomenon which can be explained is (a) Refraction (b) Interference (c) Diffraction (d) Polarisation 2. According to corpuscular theory of light, the different colours of light are due to (a) Different electromagnetic waves (b) Different force of attraction among the corpuscles (c) Different size of the corpuscles (d) None of the above 3. Huygen's conception of secondary waves (a) Allow us to find the focal length of a thick lens (b) Is a geometrical method to find a wavefront (c) Is used to determine the velocity of light (d) Is used to explain polarisation 4. The idea of the quantum nature of light has emerged in an attempt to explain (a) Interference (b) Diffraction (c) Radiation spectrum of a black body (d) Polarisation 5. Two coherent sources of light can be obtained by (a) Two different lamps (b) Two different lamps but of the same power (c) Two different lamps of same power and having the same colour (d) None of the above 6. By Huygen's wave theory of light, we cannot explain the phenomenon of (a) Interference (b) Diffraction (c) Photoelectric effect (d) Polarisation 7. The phenomenon of interference is shown by (a) Longitudinal mechanical waves only (b) Transverse mechanical waves only (c) Electromagnetic waves only (d) All the above types of waves 8. Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are (a) 5I and I (b) 5I and 3I (c) 9I and I (d) 9I and 3I 9. Light appears to travel in straight lines since (a) It is not absorbed by the atmosphere (b) It is reflected by the atmosphere (c) Its wavelength is very small (d) Its velocity is very large 10. The idea of secondary wavelets for the propagation of a wave was first given by (a) Newton (b) Huygen (c) Maxwell (d) Fresnel 11. By a monochromatic wave, we mean (a) A single ray (b) A single ray of a single colour (c) Wave having a single wavelength (d) Many rays of a single colour 12. The similarity between the sound waves and light waves is (a) Both are electromagnetic waves (b) Both are longitudinal waves (c) Both have the same speed in a medium (d) They can produce interference 13. The ratio of intensities of two waves is 9 : 1. They are producing interference. The ratio of maximum and minimum intensities will be (a) 10 : 8 (b) 9 : 1 (c) 4 : 1 (d) 2 : 1 14. A wave can transmit ...... from one place to another (a) Energy (b) Amplitude (c) Wavelength (d) Matter 15. If the ratio of intensities of two waves is 1 : 25, then the ratio of their amplitudes will be (a) 1 : 25 (b) 5 : 1 (c) 26 : 24 (d) 1 : 5 16. Two identical light sources S1 and S2 emit light of same wavelength . These light rays will exhibit interference if (a) Their phase differences remain constant (b) Their phases are distributed randomly (c) Their light intensities remain constant (d) Their light intensities change randomly 17. Wave nature of light follows because (a) Light rays travel in a straight line (b) Light exhibits the phenomena of reflection and refraction (c) Light exhibits the phenomenon of interference (d) Light causes the phenomenon of photoelectric effect
18. If L is the coherence length and c the velocity of light, the coherent time is (a) cL (b) c L (c) L c (d) Lc 1 19. If the amplitude ratio of two sources producing interference is 3 : 5, the ratio of intensities at maxima and minima is (a) 25 : 16 (b) 5 : 3 (c) 16 : 1 (d) 25 : 9 20. For constructive interference to take place between two monochromatic light waves of wavelength , the path difference should be (a) 4 (2 1)  n − (b) 2 (2 1)  n − (c) n (d) 2 (2 1)  n + 21. Two sources of waves are called coherent if (a) Both have the same amplitude of vibrations (b) Both produce waves of the same wavelength (c) Both produce waves of the same wavelength having constant phase difference (d) Both produce waves having the same velocity 22. Soap bubble appears coloured due to the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Reflection 23. Which of the following statements indicates that light waves are transverse (a) Light waves can travel in vacuum (b) Light waves show interference (c) Light waves can be polarized (d) Light waves can be diffracted 24. If two light waves having same frequency have intensity ratio 4 : 1 and they interfere, the ratio of maximum to minimum intensity in the pattern will be (a) 9 : 1 (b) 3 : 1 (c) 25 : 9 (d) 16 : 25 25. Evidence for the wave nature of light cannot be obtained from (a) Reflection (b) Doppler effect (c) Interference (d) Diffraction 26. Two light sources are said to be coherent if they are obtained from (a) Two independent point sources emitting light of the same wavelength (b) A single point source (c) A wide source (d) Two ordinary bulbs emitting light of different wavelengths 27. Wavelength of light of frequency 100Hz (a) m 6 2 10 (b) m 6 3 10 (c) m 6 4  10 (d) m 6 5 10 28. Two waves having intensity in the ratio 25 : 4 produce interference. The ratio of the maximum to the minimum intensity is (a) 5 : 2 (b) 7 : 3 (c) 49 : 9 (d) 9 : 49 29. Wavefront means (a) All particles in it have same phase (b) All particles have opposite phase of vibrations (c) Few particles are in same phase, rest are in opposite phase (d) None of these 30. Wavefront of a wave has direction with wave motion (a) Parallel (b) Perpendicular (c) Opposite (d) At an angle of  31. Which one of the following phenomena is not explained by Huygen's construction of wavefront (a) Refraction (b) Reflection (c) Diffraction (d) Origin of spectra 32. Interference was observed in interference chamber when air was present, now the chamber is evacuated and if the same light is used, a careful observer will see (a) No interference (b) Interference with bright bands (c) Interference with dark bands (d) Interference in which width of the fringe will be slightly increased 33. The ratio of intensities of two waves are given by 4 : 1. The ratio of the amplitudes of the two waves is (a) 2 : 1 (b) 1 : 2 (c) 4 : 1 (d) 1 : 4 34. For the sustained interference of light, the necessary condition is that the two sources should (a) Have constant phase difference (b) Be narrow
(c) Be close to each other (d) Of same amplitude 35. If the ratio of amplitude of two waves is 4 : 3, then the ratio of maximum and minimum intensity is (a) 16 : 18 (b) 18 : 16 (c) 49 : 1 (d) 94 : 1 36. Which of the following is conserved when light waves interfere (a) Intensity (b) Energy (c) Amplitude (d) Momentum 37. Intensity of light depends upon (a) Velocity (b) Wavelength (c) Amplitude (d) Frequency 38. Ray diverging from a point source from a wave front that is (a) Cylindrical (b) Spherical (c) Plane (d) Cubical 39. Ratio of amplitude of interfering waves is 3 : 4. Now ratio of their intensities will be (a) 9 16 (b) 49 : 1 (c) 16 9 (d) None of these 40. Two coherent sources have intensity in the ratio of 1 100 . Ratio of (intensity) max/(intensity) min is (a) 100 1 (b) 10 1 (c) 1 10 (d) 2 3 41. If two waves represented by y 4 sint 1 = and       = + 3 2 3 sin  y t interfere at a point, the amplitude of the resulting wave will be about (a) 7 (b) 6 (c) 5 (d) 3.5 42. The two waves represented by y1 = a sin(t) and cos( ) 2 y = b t have a phase difference of (a) 0 (b) 2  (c)  (d) 4  43. In a wave, the path difference corresponding to a phase difference of  is (a)    2 (b)    (c)    2 (d)    44. Two coherent sources of intensities, I1 and I2 produce an interference pattern. The maximum intensity in the interference pattern will be (a) I1 + I2 (b) 2 2 2 1 I + I (c) (I1 + I2) 2 (d) 2 1 2 ( I + I ) 45. Newton postulated his corpuscular theory on the basis of (a) Newton’s rings (b) Colours of thin films (c) Rectilinear propagation of light (d) Dispersion of white light 46. The dual nature of light is exhibited by (a) Photoelectric effect (b) Refraction and interference (c) Diffraction and reflection (d) Diffraction and photoelectric effect 47. Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is 2  at point A and  at point B. Then the difference between the resultant intensities at A and B is (a) 2I (b) 4I (c) 5I (d) 7I 48. Coherent sources are those sources for which (a) Phase difference remain constant (b) Frequency remains constant (c) Both phase difference and frequency remains constant (d) None of these 49. Wave nature of light is verified by (a) Interference (b) Photoelectric effect (c) Reflection (d) Refraction 50. Two waves are represented by the equations y a sint 1 = and cos . 2 y = a t The first wave (a) Leads the second by  (b) Lags the second by  (c) Leads the second by 2 
(d) Lags the second by 2  51. Light waves producing interference have their amplitudes in the ratio 3 : 2. The intensity ratio of maximum and minimum of interference fringes is (a) 36 : 1 (b) 9 : 4 (c) 25 : 1 (d) 6 : 4 52. Laser beams are used to measure long distance because (a) They are monochromatic (b) They are highly polarised (c) They are coherent (d) They have high degree of parallelism 53. Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio (a) 25 : 1 (b) 5 : 1 (c) 9 : 4 (d) 25 : 16 54. The frequency of light ray having the wavelength 3000 Å is (a) 9  1013 cycles/sec (b) 1015 cycles/sec (c) 90 cycles/sec (d) 3000 cycles/sec 55. Two waves have their amplitudes in the ratio 1 : 9. The maximum and minimum intensities when they interfere are in the ratio (a) 16 25 (b) 26 16 (c) 9 1 (d) 1 9 56. Huygen’s principle of secondary wavelets may be used to (a) Find the velocity of light in vacuum (b) Explain the particle behaviour of light (c) Find the new position of the wavefront (d) Explain photoelectric effect 57. What is the path difference of destructive interference (a) n (b) n( + 1) (c) 2 (n + 1) (d) 2 (2n + 1) 58. If an interference pattern have maximum and minimum intensities in 36 : 1 ratio then what will be the ratio of amplitudes (a) 5 : 7 (b) 7 : 4 (c) 4 : 7 (d) 7 : 5 59. Intensities of the two waves of light are I and 4I. The maximum intensity of the resultant wave after superposition is (a) 5 I (b) 9 I (c) 16 I (d) 25 I 60. As a result of interference of two coherent sources of light, energy is (a) Increased (b) Redistributed and the distribution does not vary with time (c) Decreased (d) Redistributed and the distribution changes with time 61. To demonstrate the phenomenon of interference, we require two sources which emit radiation (a) Of the same frequency and having a define phase relationship (b) Of nearly the same frequency (c) Of the same frequency (d) Of different wavelengths 62. When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is (a) Polarised (b) Of longer wavelength (c) Of shorter wavelength (d) Of high intensity 63. If the distance between a point source and screen is doubled, then intensity of light on the screen will become (a) Four times (b) Double (c) Half (d) One-fourth 64. Huygen wave theory allows us to know (a) The wavelength of the wave (b) The velocity of the wave (c) The amplitude of the wave (d) The propagation of wave fronts 65. The wave theory of light was given by (a) Maxwell (b) Planck (c) Huygen (d) Young 66. The phase difference between incident wave and reflected wave is 180° when light ray (a) Enters into glass from air (b) Enters into air from glass (c) Enters into glass from diamond (d) Enters into water from glass 67. Which of the following phenomena can explain quantum nature of light