Question

Unpolarized light is sent through a linear polarizer. The intensity leaving the polarizer is 12.0 candelas. A second polarizer is placed after the first at an angle of 45.0°. What is the intensity after the second polarizer?

Answer 1

From. Malus's Law for Polarization ,

$$I=I_o\cos^2(\theta)$$

Now, we have given,$I_o=12\:candelas,\theta=45^{\circ}$

Thus,

$$I=12\cos^2(45^{\circ})=6\:candelas$$