1. The refractive index of a material is 1.75. What is the polarizing angle?
a) 47.23°
b) 51.02°
c) 53.74°
d) 60.25°
Explanation: Using Brewster’s Law, Angle of incidence = tan-1μ
= tan-11.752
= 60.25.
2. A polarized light of Intensity 40 Wm2 is incident on the analyzer at a certain angle. If the transmitted beam has an Intensity of 20 Wm2, the angle made with the vertical is _____________
a) 30°
b) 45°
c) 60°
d) 75°
Explanation: Here, Io = 40 Wm-2, I = 20 Wm-2
Using Malus law, I = Iocos2θ
20 = 40 X cos2θ
cos2θ = 1⁄2
θ = 45°.
3. What angle should the beam made with the vertical, so that after passing through the analyzer, it’s intensity should become 0.86 times the initial intensity?
a) 30°
b) 45°
c) 60°
d) 75°
Explanation: Here, I = 0.86 Io
Using Malus law, I = Iocos2θ
0.86 Io = Io X cos2θ
cos2θ = 0.86
θ = 60°.
4. The sunlight as received by the observer is __________
a) Unpolarized
b) Partially Polarized
c) Polarized
d) Varying Polarizability
Explanation: The incident sunlight, when enters the earth’s atmosphere, is scattered by the particles present in the earth’s atmosphere. Due to this, the sunlight gets polarized.
5. The working of Nicole prism is based on the phenomenon of ____________
a) Refraction
b) Reflection
c) Diffraction
d) Double Refraction
Explanation: 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.
6. In the O-ray is eliminated by ____________
a) Refraction
b) Total internal reflection
c) Dispersion
d) Transmission
Explanation: 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
7. The critical angle for O-ray with respect to Canada balsam is ___________
a) 45.7°
b) 57°
c) 59°
d) 69°
Explanation: 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°.
8. 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
Explanation: 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.
9. Nicol Prism can act as a polarizer as well as an analyzer.
a) True
b) False
Explanation: 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.
10. 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°
Explanation: 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