Interference and Diffraction Multiple Choice Questions and Answers

81. The conditions for the production of constructive and destructive interference are reversed due to the fact that on striking the thin film

1. Two rays of splitted light undergo phase change of 180 degree
2. One of two rays of splitted light undergo phase change of 180 degree
3. Light is diffracted, light is polarized

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

1. absorbed
2. totally reflected
3. Partially reflected and partially transmitted
4. Totally transmitted

83. The dark lines constituting the absorption spectrum exhibited by sunlight are frequently called

1. Fresnel lines
2. Fraunhofer lines
3. Fermi lines
4. Franklin lines

84. The diffraction observed by diffraction grating can also be termed as

1. Single slit diffraction
2. double slit Diffraction
3. multiple Slit Diffraction
4. Fresnels Diffraction

85. The first reflecting telescope was built by

1. Galileo
2. Copernicus
3. Tyco Brahe
4. Isaac Newton

86. The grating used to observe, diffraction of visible light can have approximately

1. 300 lines per cm
2. 3000 lines per cm
3. 15000 lines per cm
4. 30 lines per cm

87. The interference in thin films is because

1. The film reflects some light
2. The film is thin enough so that refracted ray is close to reflected ray
3. All of above

88. The number of lines on plane gratings is 5000. If it is illuminated by a wavelength of light 6000 A^o, how many orders will be visible?

1. 3
2. 3.33
3. 4
4. 2

89. The phenomenon of diffraction can be understood using

1. Huygens principle
2. Fraunhofer
3. Uncertainty principle
4. Fresnel

90. The phenomenon of Newtons rings can be used to check the

1. Wavelength of monochromatic light
2. phase coherence of two sources
3. flatness of any glass surface
4. velocity of light