Question

Light from a sodium lamp (S) passes through two polaroid sheets P₁ and P₂ as shown in fig. What will be the effect on the intensity of the light transmitted

1. by P₁ and
2. by P₂ 

on the rotating polaroid P₁ about the direction of propagation of light? Justify your answer in both cases.

Answer 1

i. Intensity of the light at the output of I₁ = `I_0/2`.

Since one component of light will be blocked.

ii. When this polarised light is passed through P₂, the intensity of light at its output (I₂) will vary (0 to `I_0/2` and again to 0) if P₁ is rotated.