Question

Two polarizers are oriented at 58° to one another. Light polarized at a 29° angle to each polarizer passes through both. What percent reduction in intensity takes place?
%

Answer 1

In accordance with Malus's law, the fraction of intensity gets through each is cos² θ     

Here, θ is the angle between the incidentlight and the polarizer.

.Due to first polarizer: θ = 58^o ; the  fraction = cos² 58^o = 0.2808

Due to second polarizer θ =29^o fraction = cos²29^o = 0.7649

.Therefore, the total fraction that gets through is product of the two fractions

= 0.2808 x 0.7649 = 0.2148

Therefore, the 0.2148% gets through, this means thelight is reduced by 100 - 21.48 = 78.5%