Practice question

**Polarization requires transverse waves** because only transverse can have orientation perpendicular to propagation, longitudinal cannot be polarized, wave theory requires light transverse to explain polarization, polaroids transmit only component along pass-axis, unpolarized has random transverse orientations, after polaroid polarized. Wavelength in a medium λ_m = (λvₐcuuₘ/n) . Given λvₐcuuₘ = 750 nm , n = 1.5 , λ_m = (750/1.5) = 500 nm . Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and A = 2a cos(φ/2), calculation gives 500 nm, illustrating interference, diffraction and polarization principles.