Question

Unpolarised light of intensity I₀ gets polarized emerges from a polarizer. It then passes through an analyzer. The intensity of light emerging from the analyzer is I₀/8 . The angle between the polarizing direction of the polarizer and analyzer is ……………. degree

Answer 1

Since, average of  cos² θ is 1/2 so if  I₀ is intensity of unpolarised light then intensity of polarized coming out from the polarizer is 1/2

Thus,   I₁ = 1/2 I₀  ...(i)

By Malaus law, the intensity of light coming out from the analyzer

  I₂ =  I_p cos²  θ . ...(ii)

By equation (i) & (ii), we get