MHT CET202616 April 2026Evening ShiftPhysicsWave OpticsActual
Three identical polaroids P₁ , P₂ and P₃ are placed one after another. The pass axis of P₂ and P₃ are inclined at angle of 60^ and 90^ with respect to axis of P₁ . The source has an intensity I₀ . The intensity of light finally coming out is
Options
- AI₀ 2 ^2 30^ ^2 90^
- BI₀ 2 ^2 60^ ^2 30^
- CI₀ ^2 60^ ^2 30^
- Dzero
Correct answer
B. I₀ 2 ^2 60^ ^2 30^
Step-by-step solution
Initial intensity of unpolarized light from the source is I₀ . After passing through the first polaroid P₁ , the intensity becomes I₁ = I₀ 2 . The angle between the pass axes of P₁ and P₂ is ₁ = 60^ . By Malus's law, the intensity after passing through P₂ is I₂ = I₁ ^2 ₁ = I₀ 2 ^2 60^ . The pass axis of P₃ is at an angle of 90^ with respect to P₁ . The angle between the pass axes of P₂ and P₃ is ₂ = 90^ - 60^ = 30^ . The intensity after passing through P₃ is I₃ = I₂ ^2 ₂ = I₀ 2 ^2 60^ ^2 30^ . Answer: I₀ 2 ^2 60^ ^