A clear sheet of polarizing material is placed on top of a second, similar sheet so that their polarizing axes make an angle of 30° with each other.The ratio of the intensity of emerging light to incident unpolarized light is:
A)1:4
B)1:3
C)1:2
D)3:4
E)3:8

Question

Quizplus · Accepted Answer

When two polarizing sheets are placed at an angle θ, the intensity of light emerging is given by Malus's Law: I = I₀ * cos²(θ). For unpolarized light, the first sheet reduces the intensity to half, I₀/2. The second sheet further reduces it by cos²(30°), so the final intensity is (I₀/2) * (3/4) = 3I₀/8. Thus, the ratio is 3:8.

A Clear Sheet of Polarizing Material Is Placed on Top