A plane-polarized beam falls on a polarizer rotating about the ray axis with angular velocity 21 rad/s. The incident energy flux is 4.0 mW. Find the energy transmitted in one complete revolution in mJ.
Physics · Wave Optics
JEE Mains Advanced

Question

A plane-polarized beam falls on a polarizer rotating about the ray axis with angular velocity 21 rad/s. The incident energy flux is 4.0 mW. Find the energy transmitted in one complete revolution in mJ.

Physics · Wave Optics

G1 Physics · Accepted Answer

Instantaneous transmitted power is P=P₀cos²ωt. Its average over one full revolution is P₀/2. The revolution time is T=2π/ω=2π/21 s. Thus energy=(P₀/2)T=(4.0 mW/2)(2π/21)≈0.60 mJ.