Unpolarized light is passed through polarizer 1.The light then goes though polarizer 2 with its plane of polarization at 30.0° to that of polarizer 1.Polarizer 3 is placed after polarizer 2.Polarizer 3 has its plane of polarization at 30.0° to the plane of polarization of polarizer 2 and at 60.0° to that of polarizer 1.What fraction of the intensity of the original light gets though the last polarizer?
A) 0.707
B) 0.125
C) 0.281
D) 0.553

Question

Quizplus · Accepted Answer

When unpolarized light passes through the first polarizer, its intensity is reduced by half. The intensity after the second polarizer is given by Malus's Law: I = I₀ * cos²(θ), where θ is the angle between the polarizers. For the second polarizer, θ = 30°, so the intensity is (1/2) * cos²(30°) = (1/2) * (3/4) = 3/8. For the third polarizer, θ = 30° again, so the intensity is (3/8) * cos²(30°) = (3/8) * (3/4) = 9/32, which is approximately 0.281.

Unpolarized Light Is Passed Through Polarizer 1