Engineering Physics Multiple Choice Questions on “Nicol Prism”.
1. The working of Nicole prism is based on the phenomenon of ____________
a) Refraction
b) Reflection
c) Diffraction
d) Double Refraction
Answer: d
Clarification: The working of Nicol Prism is based on the phenomenon of Double Refraction. When a beam of unpolarized light passes through a doubly refracting crystal such as calcite, it splits into two plane-polarized beams.
2. In the O-ray is eliminated by ____________
a) Refraction
b) Total internal reflection
c) Dispersion
d) Transmission
Answer: b
Clarification: In a Nicol Prism, the O-ray is eliminated by total internal reflection while the E-ray is transmitted through the Nicol Prism. Thus, a plane polarized light with vibrations in the principal section of the crystal is obtained.
3. In the Nicol Prism experiment, the calcite crystal length is x times its breadth. What is x?
a) 2
b) 3
c) 1/2
d) 1/3
Answer: b
Clarification: In this experiment, a calcite crystal whose length is three times its breadth is taken. The calcite crystal is the doubly refracting crystal that splits the unpolarized light into two plane-polarized beams.
4. For E-ray, the Canada balsam layer is optically rarer.
a) True
b) False
Answer: b
Clarification: Canada Balsam is a transparent substance, whose refractive index lies between the refractive indices of O-ray and E-ray. Thus, for an E-ray, it is optically denser while for an O-ray it is optically rarer.
5. The critical angle for O-ray with respect to Canada balsam is ___________
a) 45.7°
b) 57°
c) 59°
d) 69°
Answer: d
Clarification: We know Canada balsam is optically denser than calcite for O-ray. The refractive index for O-ray is 1.069 while the critical angle turns out to be 69°.
6. The prism does not act as a polarizer when _____________
a) The angle of incidence is less than the critical angle for the O-ray
b) The angle of incidence is greater than the critical angle for the O-ray
c) The angle of incidence is less than the critical angle for the E-ray
d) The angle of incidence is greater than the critical angle for the E-ray
Answer: a
Clarification: If the angle of incidence is less than the critical angle for the O-ray, it is not reflected and is transmitted through the prism and so the prism does not act as a polarizer.
7. Nicol Prism can act as a polarizer as well as an analyzer.
a) True
b) False
Answer: a
Clarification: Nicol Prism can be used as a Polarizer as well as an analyzer. Thus, it can polarize an unpolarized light and also detect a plane-polarized light.
8. What should be the maximum angle between the extreme rays of the incident beam for the Nicol prism to work perfectly as a polarizer?
a) 25°
b) 28°
c) 34°
d) 43°
Answer: b
Clarification: The angle between the extreme rays of the incident beam should be less than 28o so as to avoid the total internal reflection of E-ray and the transmission of O-ray.
9. The combination as shown in the figure is called as _____________
a) Polarimeter
b) Polaroid
c) Polariscope
d) Polarizer and Analyzer