Interference and Diffraction Objective Question and Answer
Interference and Diffraction MCQ Multiple Choice Questions - Page 4 for Practice
91. What is true for intensity of scattered light according to Rayleighs law?
Correct Answer is: The light of smallest wavelength will be scattered more
92. When a light ray travelling in glass is incident on an air surface
Correct Answer is: all of A, B, and C
93. When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to
Correct Answer is: pi
94. When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to
Correct Answer is: pi
95. When electromagnetic waves strike the boundary of denser medium they are
Correct Answer is: Reflected out of phase by 180 degree
96. When light passes from air into water, the frequency of the light remains the same. What happens to the speed? And the wavelength of light as it crosses the boundary in going from air into water? Speed Wavelength
Correct Answer is: Decreases Decreases
97. When Newtons rings interference pattern is viewed from above by means of reflected light, the central spot is
Correct Answer is: Dark
98. Which of the following condition is essential for observing Fraunhofer diffraction?
Correct Answer is: Both source and screen must be at infinity
99. Which of the following does not support the wave nature of light
Correct Answer is: Compton effect
100. Which of the following does NOT travel in a vacuum?
Correct Answer is: Sound waves
101. Which of the following phenomenon cannot be explained on the particle nature of light
Correct Answer is: Photo Electric Effect
102. Which of the following phenomenon produces colors in soap bubble?
Correct Answer is: Interference
103. Whose principle or law states that each point on a wave front may be considered a new wave source? Is it
Correct Answer is: Huygenss Principle
104. Why in Newtons rings setup, the beam splitter (mirror) is kept at 450?
Correct Answer is: It allows light rays to incident at 900 over the top surface of Planoconvex lens
105. Why in Newtons rings the center spot is always dark?
Correct Answer is: All of above
106. X-ray diffraction can be observed by using
Correct Answer is: Diffraction Grating
107. A beam of light is incident on a large block of glass. The index of refraction of the glass is greater than one. Is the wavelength of the light in the glass?
Correct Answer is: Shorter than
108. A beam of white light is passed through a diffraction grating and the resulting spectrum is allowed to fall on a screen. Which one of the following is the color of light that undergoes the greatest deviation from its original direction? Is it
Correct Answer is: Red
109. A color with a wavelength longer than that of yellow is
Correct Answer is: Red
110. A diffraction grating is optically equivalent to a multiple slit system in which the number of slit, N is typically
Correct Answer is: 5000/cm
111. A film is said to be thin if its thickness is
Correct Answer is: Comparable with one wavelength of light
112. A grating has 6000 lines per cm. How many orders of light of wavelength 4500 Ao can be seen?
Correct Answer is: 3
113. A monochromatic (single frequency, single wavelength) light ray in air (n = 1) enters a glass prism (n = 1.5). In the glass prism
Correct Answer is: The frequency is the same, but the wavelength is greater than in air
114. A slit of width a is illuminated by white light. For what value of a will the first minimum for red light fall at an angle of 300 wavelength of red light is 6500 Ao
Correct Answer is: 1.3 X 10-4cm
115. A thin film is observed in white light. The color of the film seen at a particular point depends upon
Correct Answer is: Location of observer
116. A wavelength is commonly measured in which one of the following units?
Correct Answer is: Angstroms
117. A wedge shaped thin has
Correct Answer is: Zero thickness at one end and it increasing towards other end
118. A wedge shaped thin has
Correct Answer is: Zero thickness at one end and it increasing towards other end
119. An index of refraction less than one for a medium would imply
Correct Answer is: That the speed of light in the medium is greater than the speed of light in vacuum
120. An index of refraction less than one for a medium would imply
Correct Answer is: That the speed of light in the medium is greater than the speed of light in vacuum
