Interference and Diffraction Multiple Choice Questions and Answers

91. The points of constructive interference of light are

1. Always bright
2. may be bright or dark
3. always dark
4. neither bright nor dark

92. The principle on which fiber optics is based is

1. refraction
2. polarization
3. Dispersion.
4. Total internal reflection

93. The Radius (or diameter) of bright rings in Newtons rings is

1. Directly proportional to the square root of odd numbers
2. Inversely proportional to the square root of natural numbers
3. Directly proportional to the square root of even numbers
4. Directly proportional to the square root of natural numbers

94. The Radius (or diameter) of dark rings in Newtons rings is

1. Directly proportional to the square root of odd numbers
2. Inversely proportional to the square root of natural numbers
3. Directly proportional to the square root of even numbers
4. Directly proportional to the square root of natural numbers

95. The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called

1. IR
2. Ultra-Violet
3. RF
4. Gamma ray

96. The speed of any mechanical wave as it propagates through a medium is dependent mainly on the

1. frequency of the wave source
2. wavelength
3. period of the wave
4. type of medium through which the wave travels

97. 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?

1. 1.5
2. 1
3. 0.8
4. 1.25

98. The wave nature of light is demonstrated by which of the following?

1. The photoelectric effect
2. Color
3. The speed of light
4. Diffraction

99. There are two types of diffraction Fresnel and ..........

1. Michelson
2. De Broglie
3. Fraunhofer
4. Huygens

100. To find prominent diffraction, the size of diffraction object should be

1. greater than wavelength of light used
2. comparable to order of wavelength of light
3. less than wavelength of light used
4. none of these