Polarization and Brewster’s law - Question Bank

1. A linearly polarized light beam passes through a quarter-wave plate. The emergent light will be:
A) Linearly polarized
B) Circularly polarized
C) Unpolarized
D) Elliptically polarized
2. What is the primary application of polarization in photography?
A) To increase contrast
B) To reduce glare and reflections
C) To enhance colors
D) To achieve wide-angle effects
3. If the refractive index of a medium is 1.5, what is the angle of refraction when light is incident at Brewster's angle?
A) 33.7°
B) 45°
C) 56.3°
D) 90°
4. The E-ray in double refraction is:
A) Always travels along the optic axis
B) Follows Snell's law with a variable refractive index
C) Has a constant refractive index equal to the ordinary refractive index
D) Is always unpolarized
5. When light is passed through a Nicol prism, it is split into two rays. One ray is the O-ray and the other is the E-ray. The O-ray is:
A) Plane polarized in the direction of the optic axis
B) Plane polarized perpendicular to the optic axis
C) Unpolarized
D) Not affected by the crystal's refractive index
6. The intensity of light after passing through a polarizer is I₀/2. What can be said about the incident light?
A) It was unpolarized.
B) It was plane polarized.
C) It was circularly polarized.
D) It was elliptically polarized.
7. If the refractive index of a medium is n, and light is incident at Brewster's angle i_p, then the angle of refraction r satisfies:
A) i_p + r = 90°
B) i_p = r
C) i_p + r = 180°
D) i_p = 2r
8. What is the term for the angle of incidence at which the reflected ray is perpendicular to the refracted ray?
A) Critical angle
B) Brewster's angle
C) Angle of refraction
D) Angle of minimum deviation
9. A beam of light is incident on a transparent medium. The reflected and refracted rays are perpendicular. This implies that the angle of incidence is:
A) 0°
B) 45°
C) Equal to the critical angle
D) Brewster's angle
10. Which of the following statements about polarization is incorrect?
A) Light reflected from a rough surface is generally partially polarized.
B) Light transmitted through a Polaroid sheet is plane polarized.
C) Malus's law applies to unpolarized light.
D) At Brewster's angle, the reflected and refracted rays are perpendicular.
11. If the refractive index of glass is 1.6, what is Brewster's angle for light going from air to glass?
A) tan⁻¹(1.6)
B) tan⁻¹(0.6)
C) tan⁻¹(1/1.6)
D) tan⁻¹(0.4)
12. What is the minimum angle of incidence for total internal reflection to occur?
A) 0°
B) Brewster's angle
C) Critical angle
D) 90°
13. A Nicol prism separates a beam of light into two rays. These rays are:
A) Both unpolarized
B) One unpolarized and one polarized
C) Two plane-polarized rays vibrating at right angles to each other
D) Two circularly polarized rays
14. Consider two polarizers with their axes at 90° to each other. If unpolarized light of intensity I₀ is incident on the first polarizer, what is the intensity of light transmitted through the second polarizer?
A) I₀
B) I₀/2
C) 0
D) I₀/4
15. In the context of polarization by reflection, when the angle of incidence is Brewster's angle, the angle between the reflected ray and the refracted ray is:
A) 0°
B) 45°
C) 90°
D) 180°
16. If light is reflected from a surface such that the angle of incidence equals the angle of refraction, what is the state of the reflected light?
A) Unpolarized
B) Plane polarized
C) Circularly polarized
D) Partially polarized
17. What is the relationship between Brewster's angle (i_p) and the refractive index (n) for light traveling from vacuum to a medium?
A) tan(i_p) = n
B) n = tan(i_p)
C) tan(i_p) = 1/n
D) n = sin(i_p)
18. The phenomenon of polarization demonstrates that light is a wave of what nature?
A) Longitudinal
B) Transverse
C) Scalar
D) Electromagnetic with electric field parallel to propagation
19. When light is incident normally on a polarizing film, the transmitted light is:
A) Unpolarized
B) Linearly polarized
C) Circularly polarized
D) Elliptically polarized
20. Which of the following optical elements can be used to convert circularly polarized light into linearly polarized light?
A) A polarizer
B) An analyzer
C) A quarter-wave plate
D) A Nicol prism
21. A beam of light is incident on a liquid of refractive index n at an angle i. If the reflected beam is completely polarized, then:
A) tan(i) = n
B) tan(i) = 1/n
C) sin(i) = n
D) cos(i) = n
22. What is the state of polarization of light reflected from a surface when the angle of incidence is less than Brewster's angle?
A) Completely polarized
B) Unpolarized
C) Partially polarized
D) Circularly polarized
23. If the angle between the transmission axes of two polarizers is 45°, and the first polarizer transmits light of intensity I₁, what is the intensity transmitted by the second polarizer?
A) I₁ cos(45°)
B) I₁ sin²(45°)
C) I₁ cos²(45°)
D) I₁/2
24. When unpolarized light of intensity I₀ passes through a polarizer and then through an analyzer whose axis is at an angle θ with the polarizer's axis, the final transmitted intensity is:
A) I₀ cos(θ)
B) I₀ sin²(θ)
C) I₀ cos²(θ)
D) I₀/2
25. Polaroid sunglasses reduce glare because:
A) They absorb all wavelengths of light equally
B) They are coated with a reflective material
C) They block horizontally polarized light, which is dominant in glare
D) They increase the intensity of light
26. What is the optical phenomenon responsible for the blue color of the sky?
A) Interference
B) Diffraction
C) Polarization by scattering
D) Total internal reflection
27. If the refractive index of a medium is n, and light is incident at Brewster's angle i_p, then the angle of refraction r is given by:
A) r = 90° - i_p
B) r = i_p
C) r = 90° - tan⁻¹(n)
D) r = tan⁻¹(n)
28. When light is incident at Brewster's angle, the reflected and refracted rays are perpendicular. This means the sum of Brewster's angle (i_p) and the angle of refraction (r) is:
A) 45°
B) 90°
C) 135°
D) 180°
29. What is the condition for the reflected light to be completely polarized when unpolarized light is incident on a medium?
A) Angle of incidence = 0°
B) Angle of incidence = 90°
C) Angle of incidence = Brewster's angle
D) Angle of incidence = 45°
30. A half-wave plate is used to:
A) Change linearly polarized light to circularly polarized light
B) Rotate the plane of polarization of linearly polarized light by an angle 2θ, where θ is the angle between the polarization direction and the optic axis
C) Convert unpolarized light into polarized light
D) Produce circularly polarized light
31. What is a quarter-wave plate used for?
A) To produce linearly polarized light from circularly polarized light
B) To produce circularly polarized light from linearly polarized light
C) To reduce the intensity of light
D) To measure Brewster's angle
32. The ordinary ray in double refraction follows Snell's law, while the extraordinary ray:
A) Does not follow Snell's law
B) Follows Snell's law but with a different refractive index
C) Is always reflected
D) Undergoes diffraction
33. In a crystal exhibiting double refraction, the two rays produced are called the ordinary ray and the:
A) Refracted ray
B) Extraordinary ray
C) Diffracted ray
D) Incident ray
34. What is the phenomenon of double refraction?
A) Light splitting into two polarized beams when passing through certain crystals
B) Light bending at an interface
C) Light reflecting from two surfaces
D) Light diffracting through a narrow slit
35. When light is scattered by small particles in the atmosphere, the scattered light is:
A) Unpolarized
B) Partially polarized
C) Completely polarized
D) Linearly polarized in the vertical direction
36. Which of the following is NOT a method of producing polarized light?
A) Polarization by reflection
B) Polarization by scattering
C) Polarization by double refraction
D) Polarization by interference
37. If light is incident on a glass surface (n=1.5) at Brewster's angle, what is the approximate value of Brewster's angle?
A) 30°
B) 45°
C) 56.3°
D) 90°
38. What is the state of polarization of light reflected from a smooth water surface at Brewster's angle?
A) Unpolarized
B) Completely polarized vertically
C) Completely polarized horizontally
D) Partially polarized
39. At Brewster's angle, the reflected ray and the refracted ray are:
A) Parallel
B) Perpendicular
C) At an angle of 45°
D) Co-linear
40. If the refractive index of a medium is 'n', then Brewster's angle (i_p) is given by:
A) tan(i_p) = n
B) tan(i_p) = 1/n
C) sin(i_p) = n
D) cos(i_p) = n
41. Brewster's law states that the tangent of the polarizing angle (Brewster's angle) is equal to:
A) The refractive index of the reflecting medium
B) The reciprocal of the refractive index of the reflecting medium
C) The square of the refractive index of the reflecting medium
D) The sine of the refractive index of the reflecting medium
42. What is Brewster's angle?
A) The angle at which light is totally reflected
B) The angle of incidence at which reflected light is completely polarized
C) The angle at which light undergoes maximum diffraction
D) The angle for total internal reflection
43. When is the intensity of light transmitted through two crossed polarizers zero?
A) When the angle between their axes is 0°
B) When the angle between their axes is 45°
C) When the angle between their axes is 90°
D) When the angle between their axes is 180°
44. According to Malus's Law, if a polarizer is followed by an analyzer, and the angle between their transmission axes is θ, the transmitted intensity I is related to the initial intensity I₀ by:
A) I = I₀ cos(θ)
B) I = I₀ cos²(θ)
C) I = I₀ sin²(θ)
D) I = I₀ tan²(θ)
45. What is Malus's Law used to determine?
A) The intensity of light after passing through two polarizers
B) The angle of incidence for total internal reflection
C) The wavelength of light
D) The refractive index of a medium
46. When unpolarized light passes through a polarizing filter, what is the intensity of the transmitted light compared to the incident light?
A) It is halved
B) It remains the same
C) It increases by 50%
D) It becomes zero
47. A Nicol prism is a common type of:
A) Polarizer
B) Analyzer
C) Both polarizer and analyzer
D) Half-wave plate
48. What is the name of the device used to produce or analyze polarized light?
A) Spectrometer
B) Polarimeter
C) Interferometer
D) Diffractometer
49. Which type of light is naturally polarized?
A) Light emitted by a laser
B) Light reflected from a non-metallic surface
C) Light from the Sun
D) Light from an incandescent bulb
50. What phenomenon describes the process of restricting the vibrations of light waves to a particular plane?
A) Diffraction
B) Interference
C) Polarization
D) Refraction