CBSE Class 12 Physics Wave Optics Quiz 1

1. What happens if one of the slits, say S₁ in Young's double , slit experiment-is covered with a glass plate which absorbs half the intensity of light from it?

A The bright fringes become less-bright and the dark fringes have a finite light intensity B The bright fringes become brighter and the dark fringes become darker C The fringe width decreases D No fringes will be observed

2. What happens to the interference pattern the two slits S₁ and S₂ in Young's double experiment are illuminated by two independent but identical sources?

A The intensity of the bright fringes doubled B The intensity of the bright fringes becomes four times C Two sets of interference fringes overlap D No interference pattern is observed

3. What is the reason for your answer to the above question?

A The two sources do not emit light of the same wavelength B The two sources emit waves which travel with different speeds C The two sources emit light waves of different amplitudes D There is not constant phase difference between the waves emitted by the two sources

4. A single slit diffraction pattern is obtained using a beam of red light What happened the red light is replaced by the blue light?

A There is no change in diffraction pattern B Diffraction fringes become narrower and crowded C Diffraction fringes become broader and farther apart D The diffraction pattern disappear

5. When a polaroid is rotated, the intensity of light varies but never reduces to zero. It shows that the incident light is:

A unpolarised B completely plane polarised C partially plane polarised D None of the above

6. When a polaroid is rotated, the intensity of light does not vary. The incident light may be:

A unpolarised B completely polarised C partially plane polarised D None of the above

7. In Young's double slit experiment, a maximum is obtained when the path difference between the interfering waves is (n ∈ l):

A nλ B n \(\frac{λ}{2}\) C (2n + 1) \(\frac{λ}{2}\) D (2n - 1) \(\frac{λ}{4}\)

8. For sustained interference, we need two sources which emit radiations :

A of the same intensity B of the same amplitude C having a constant phase difference D None of these

9. Two sources of light are said to be coherent when both give out light waves of the same:

A amplitude and phase B intensity and wavelength C speed D wavelength and a constant phase difference

10. The intensity of light emerging from the two slits, in Young's experiment is in the ratio 1 : 4. The ratio of,the intensity of the minimum to that of the consecutive maximum will be:

A 1 : 4 B 1 : 9 C 1 : 16 D 2 : 3