In a stack of three polarizing sheets the first and third are crossed while the middle one has its axis at 45° to the axes of the other two.The fraction of the intensity of an incident unpolarized beam of light that is transmitted by the stack is:
A)1/2
B)1/3
C)1/4
D)1/8
E)0

Question

Quizplus · Accepted Answer

When an unpolarized beam of light passes through the first polarizer, it becomes polarized and its intensity is reduced by half. The middle polarizer, oriented at 45 degrees to the first, further reduces the intensity by a factor of 1/2 (due to Malus's law). The third polarizer, being crossed with the first, again reduces the intensity by 1/2. Therefore, the total transmitted intensity is (1/2) * (1/2) * (1/2) = 1/8.

In a Stack of Three Polarizing Sheets the First and Third