Question

what is malus law ? ( in simple words)

Answer 1

When a perfect polarizer is placed in a polarized beam of the light I, that passes through it, dependent upon the angle between the lights initial polarization direction and the axis of polarizer I=10cos^2

Answer 2

According to law of malus when a plane polarized light is incident on analyser then the intensity of transmitted light(I) is directly propositional to square of cosine of angle between polariser and analyser.
Note;- Applied only at analyser
I directly cos²α
I=I₀ cos²α