Question

What angle is needed between the direction of polarized light and the axis of a polarizing filter to cut its intensity in half?

Answer 1

Answer:

45 degree

Explanation:

Let the initial intensity is Io and the angle between the polarizer and the axis of filter is θ.

The intensity of light passing after filter is 0.5 Io.

By using the law of Malus,

$I=I_{0} Cos^{2}\theta$

$0.5I_{0}=I_{0} Cos^{2}\theta$

$0.5= Cos^{2}\theta$

$0.707= Cos\theta$

θ = 45 degree