Theories of light and interference
1. The idea of quantum nature of light has emerged in an attempt to explain
(a) Interference
(b) Diffraction
(c) Radiation spectrum of black body
(d) Polarization
Ans: ( c)
2. According to Newton’s corpuscular theory, the velocity of light in rarer medium as compared to that in denser medium is:
(a) Less
(b) More
(c) Sometimes less, sometimes more
(d) Much less
Ans: (a)
3. A very thin film in reflected white light appears:
(a) Coloured
(b) White
(c) Black
(d) Red.
Ans: ( c)
4. Light appears to travel in straight lines since
(a) It is not absorbed by the atmosphere
(b) It is reflected by the atmosphere
(c) Its wavelength is very small
(d) Its velocity is very large.
Ans: (c)
5. Intensity of light depends on
(a) Amplitude
(b) Frequency
(c) Wavelength
(d) Velocity
Ans: ( a)
6. The colour of bright fringe nearest central achromatic fringe in the interference pattern with white light will be:
(a) Violet
(b) Red
(c) Green
(d) Yellow..
Ans: (a)
7. Pick out the longest wavelength from the following types of radiations:
(a) Blue light
(b) Gamma rays
(c) X-rays
(d) Red light.
Ans: (d)
8. Which out of following cannot produce two coherent sources?
(a) Liod’s mirror
(b) Fresnel biprism
(c) Young’s double slit
(d) Prism
Ans: (d)
9. When light passes from one medium into another medium, then the physical property which does not change, is:
(a) Velocity
(b) Wavelength
(c) Frequency
(d) Refractive index.
Ans: (c)
10. Two sources of light are said to be coherent, when they give light waves of same:
(a) Amplitude and phase
(b) Wavelength and constant phase difference
(c) Intensity and wavelength
(d) Phase and speed.
Ans: (b)