Interference and Diffraction Objective Question and Answer
Interference and Diffraction MCQ Multiple Choice Questions - Page 3 for Practice
61. Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced. What will be the effect on bandwidth?
Correct Answer is: Bandwidth increases
62. Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the thin film is replaced by the film of higher refractive index. What will be the effect on bandwidth?
Correct Answer is: Bandwidth decreases
63. Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern?
Correct Answer is: It will be a mixture of all colors
64. Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern?
Correct Answer is: It will be a mixture of all colors
65. Light enters air from water. The angle of refraction will be
Correct Answer is: Less than the angle of incidence.
66. Light is
Correct Answer is: all of the above
67. Light travels fastest
Correct Answer is: In a vacuum
68. Newtons light illustrate the phenomenon of
Correct Answer is: Interference
69. Newtons light illustrate the phenomenon of
Correct Answer is: Interference
70. Newtons rings are formed because of interference between the light Reflected from
Correct Answer is: Lower surface of Plano-convex lens and upper surface of plane glass plate
71. Newtons rings experiment is performed and radius (or diameter) is calculated. Now Plano-convex lens is replaced with another Plano-convex lens of greater Radius of curvature. What will be effect on radius (or diameter)?
Correct Answer is: Radius (or diameter) will increase
72. Newtons rings experiment is performed with air gap between lens and plate. Now that gap is filled with water. What will be effect on radius (or diameter)?
Correct Answer is: Radius (or diameter) will decrease
73. On a rainy day, small oil films on water show brilliant colors. This is due to
Correct Answer is: interference
74. Optical fiber works on the
Correct Answer is: total internal reflection
75. Radio telescopes are better than optical telescopes because
Correct Answer is: All of the above
76. Rainbow is due to
Correct Answer is: refraction and reflection of sunlight by water droplets
77. Second glass plate in Michelson s Interferometer is known as
Correct Answer is: Compensating glass plate
78. significant diffraction of X ray can be obtained
Correct Answer is: By a single slit
79. The angle of incidence for a wave
Correct Answer is: all of the above
80. The characteristic that distinguishes a laser beam from an ordinary light beam is
Correct Answer is: The coherence of the laser beam
81. 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
82. 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
83. The dark lines constituting the absorption spectrum exhibited by sunlight are frequently called
Correct Answer is: Fraunhofer lines
84. The diffraction observed by diffraction grating can also be termed as
Correct Answer is: Single slit diffraction
85. The first reflecting telescope was built by
Correct Answer is: Isaac Newton
86. The grating used to observe, diffraction of visible light can have approximately
Correct Answer is: 15000 lines per cm
87. The interference in thin films is because
Correct Answer is: All of above
88. 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
89. The phenomenon of diffraction can be understood using
Correct Answer is: Huygens principle
90. The phenomenon of Newtons rings can be used to check the
Correct Answer is: Wavelength of monochromatic light
