Question

If unpolarized light passes through a filter, how does the intensity change?

Answer 1

here,

A light wave that is vibrating in more than one plane is referred to as unpolarized light

In general, it is helpful to picture unpolarized light as a wave that has an average of half its vibrations in a horizontal plane and half of its vibrations in a vertical plane.

It is possible to transform unpolarized light into polarized light. Polarized light waves are light waves in which the vibrations occur in a single plane.

so ,when an unpolarized light passes through a filter

for single plane

the intensity of light is Halved