Question

Explain why the intensity of light coming out of a polaroid does not change

Answer 1

When unpolarized light passes through a polariser, vibrations perpendicular to the axis of the polaroid are blocked. Unpolarized light have vibrations in all directions.  Hence for all positions of polaroid, half of the incident light gets transmitted. Hence, the intensity of the light does not change.

Answer 2

Explanation:

the intensity of light does not change irrespective of the orientation of pass-axis of the polaroid. Light waves are transverse waves. So, they have electric vectors in all possible directions. ... the electric vectors which are parallel to the pass-axis of the polaroid pass through it.