Interference and Diffraction Objective Question and Answer
Interference and Diffraction MCQ Multiple Choice Questions - Page 3 for Practice
61. The angle of incidence for a wave
Correct Answer is: all of the above
62. The characteristic that distinguishes a laser beam from an ordinary light beam is
Correct Answer is: The coherence of the laser beam
63. The conditions for the production of constructive and destructive interference are reversed due to the fact that on striking the thin film
Correct Answer is: Two rays of splitted light undergo phase change of 180 degree
64. The critical angle for a beam of light passing from water into air is 48.8 degree. This means that all light rays with an angle of incidence greater than this angle will be
Correct Answer is: Partially reflected and partially transmitted
65. The dark lines constituting the absorption spectrum exhibited by sunlight are frequently called
Correct Answer is: Fraunhofer lines
66. The diffraction observed by diffraction grating can also be termed as
Correct Answer is: Single slit diffraction
67. The first reflecting telescope was built by
Correct Answer is: Isaac Newton
68. The grating used to observe, diffraction of visible light can have approximately
Correct Answer is: 15000 lines per cm
69. The interference in thin films is because
Correct Answer is: All of above
70. The number of lines on plane gratings is 5000. If it is illuminated by a wavelength of light 6000 Ao, how many orders will be visible?
Correct Answer is: 3
71. The phenomenon of diffraction can be understood using
Correct Answer is: Huygens principle
72. The phenomenon of Newtons rings can be used to check the
Correct Answer is: Wavelength of monochromatic light
73. The points of constructive interference of light are
Correct Answer is: Always bright
74. The principle on which fiber optics is based is
Correct Answer is: Total internal reflection
75. The Radius (or diameter) of bright rings in Newtons rings is
Correct Answer is: Directly proportional to the square root of odd numbers
76. The Radius (or diameter) of dark rings in Newtons rings is
Correct Answer is: Directly proportional to the square root of natural numbers
77. The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called
Correct Answer is: Ultra-Violet
78. The speed of any mechanical wave as it propagates through a medium is dependent mainly on the
Correct Answer is: type of medium through which the wave travels
79. The speed of light in material A is 1.25 times as large as it is in material. What is the ratio of the refractive indices, µA /µB of these materials?
Correct Answer is: 1.25
80. The wave nature of light is demonstrated by which of the following?
Correct Answer is: Diffraction
81. There are two types of diffraction Fresnel and ..........
Correct Answer is: Fraunhofer
82. To find prominent diffraction, the size of diffraction object should be
Correct Answer is: comparable to order of wavelength of light
83. Two sources of light are said to be coherent if
Correct Answer is: they produce waves of the same amplitude
84. What is the effect of increasing the number of slits on the intensity of Central maxima of diffraction pattern of a diffraction grating?
Correct Answer is: Intensity of central maxima will increase
85. What is the highest order spectrum which may be seen with monochromatic light of wavelength 5000 Ao by means of diffraction grating with 5000 lines/cm?
Correct Answer is: 4
86. What is the name of the process whereby waves travel around corners and obstacles in their paths?
Correct Answer is: Diffraction
87. What is the nature of interference pattern at the contact edge of wedge shaped film
Correct Answer is: Always dark
88. What is the nature of interference pattern for thin film of wedge shaped
Correct Answer is: Convex outside
89. What is the nature of interference pattern for thin film of wedge shaped
Correct Answer is: Convex outside
90. What is the speed of light in glycerin (n = 1.47) expressed in terms of the speed of light in a vacuum?
