An unpolarised beam of intensity `I_(0)` is incident on a pair of nicols making an angle of `60^(@)` with each other. The intensity of light emerging from the pair is

Options

A. `9`
B. `(1)/(4)`
C. `(1)/(8)`
D. `(3)/(8)`

Answer

B

Explanation

If `I_(0)` is the intensity of light incident on the first polarizer, then the intensity which comes out of it is `I_(1)=I_(0)//2`. This is the intensity incident on the second polarizer which is crossed at an angle of `60^(@)`. Therefore, the intensity thet comes out of this second polarizer is `I_(2)=I_(1)cos^(2)60^(@)=I_(0)//8` .