Question

Unpolarized light passes through two polarizers whose transmission axes are at an angle of 30.0 degrees with respect to each other. What fraction of the incident intensity is transmitted through the polarizers?a.) 0.750b.) 0.866c.) 0.375d.) 0.627

Answer 1

Answer:

a) 0.750

Explanation:

When the unpolarized light passes through the first polarizer, it becomes polarized along the axis of transmission of the polarizer itself.

Then, the light passes through the second polarizer, whose axis of transmission is inclined by an angle $\theta$ with respect to the direction of polarization of the light.

Calling $I_0$ the initial intensity of the light, the intensity of light passing through the second filter is

$I=I_0 cos^2 \theta$

where

$\theta=30^{\circ}$

Solving the formula for $\frac{I}{I_0}$, which is the fraction of the incident intensity transmitted through the second polarizer, we find

$\frac{I}{I_0}=cos^2 \theta = cos^2 30^{\circ}=0.750$