Multiple choice questions of Chapter 9 of Physics for First Year.

1. The locus of all points in a medium having the same phase of vibration is called
a) Crest
b) Trough
c) Wavelength
d) Wave front

2. The distance between two consecutive wave fronts is called:
a) Time period
b) Frequency
c) Wavelength
d) Displacement

3. Which one of the following is nearly monochromatic light?
a) Light form fluorescent tube
b) Light form sodium lamp
c) Light form neon lamp
d) Light form simple lamp

4. Two sources of light are coherent if they emit rays of
a) Same wavelength
b) Same amplitude of vibration
c) Same wave length with constant phase difference
d) Same amplitude and wavelength

5. Sodium chloride in a flame gives out pure:
a) Blue light
b) Yellow light
c) Red light
d) White light

6. When crest of one wave falls over the trough of the other wave, this phenomenon is known as
a) Polarization
b) Constructive interference
c) Destructive interference
d) Diffraction

7. The condition for constructive interference of two coherent beams is that the path difference should be
a) Integral multiple of λ/2
b) Integral multiple of λ
c) Odd Integral multiple of λ/2
d) Even integral multiple of λ

8. The condition for destructive interference of two coherent beams is that the path difference should be
a) Integral multiple of λ/2
b) Integral multiple of λ
c) Odd Integral multiple of λ/2
d) Even integral multiple of λ

9. In Young double slit experiment, if white light is used
a) Alternate dark and bright fringes will be seen
b) Colored fringes will be seen
c) No interference fringes will be seen
d) Impossible to predict

10. The center of Newton’s rings is_________ due to destructive interference:
a) Bright
b) Dark
c) Colorless
d) Red

11. When the Newton’s rings are observed with reflected light, the central spot is:
a) Red
b) Blue
c) Dark
d) Bright

12. When the Newton’s rings are observed with transmitted light, the central spot is:
a) Red
b) Blue
c) Dark
d) Bright

13. The appearance of Color in thin films is due to
a) Diffraction
b) Dispersion
c) Interference
d) Polarization

14. Soap film exhibit brilliant colors in sun light due to:
a) Dispersion of light
b) Interference of light
c) Diffraction of light
d) Scattering of light

15. 2𝑑sin𝜃 = 𝑚𝜆 is called:
a) Laplace’s equaiton
b) Reflection equation
c) Refraction equaion
d) Bragg’s equation

16. 𝑑sin𝜃 = 𝑚𝜆 is called:
a) Laplace’s equaiton
b) Slit Diffraction Condition
c) Refraction equaion
d) Bragg’s equation

17. Bending of light around the edges of an obstacle is known as:
a) Refraction
b) Polarization
c) Diffraction
d) Interference

18. The bending of a beam of light when it passes from one medium to another is known as:
a) Refraction
b) Reflection
c) Diffraction
d) Dispersion

19. The effective path difference between two reflected beams, in x-ray diffraction by crystal is:
a) 𝑑sin𝜃
b) 2𝑑sin𝜃
c) 𝑑sin𝜃 2
d) 𝑑sin2𝜃