JEE Main 2024 Physics question
A beam of unpolarised light of intensity I₀ is passed through a Polaroid A and then through another Polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of emergent light is:
Answer: (B)
Solution
After A the intensity is I₀/2. By Malus's law, I = (I₀/2)cos²45° = I₀/4.