If a reflected ray in air at an angle of reflection of 60° is totally polarized, what is the index of refraction of the reflecting material?
A) 1.50
B) 2.00
C) 1.73
D) 1.15
E) this angle is not possible for an incident ray in air

Question

Quizplus · Accepted Answer

When an unpolarized light is reflected at a certain angle (called Brewster's angle), the reflected light becomes totally polarized. At this angle, the reflected ray and the refracted ray are at right angles to each other. This angle is given by the formula:
tan θ = n,
where θ is the angle of incidence and n is the index of refraction of the reflecting material. Thus, for an incident ray at 60 degrees in air, we have:
tan 60 = n
n = √3 ≈ 1.73
Therefore, the correct answer is C.

If a Reflected Ray in Air at an Angle of Reflection