A beam of natural light falls on a system of 5 polaroids, which are arranged in succession such that the pass axis of each polaroid is turned through `60^(@)` with respect to the precending one. The friction of the incident light intensity that passes through the system is :

Options

A. `1//64`
B. `1//32`
C. `1//256`
D. `1//128`

Answer

D

Explanation

Intensity after 1st polaroid,
`I_(1)= (I_(0))/(2)`
Intensity after 2nd polaroid,
`I_(2)= I_(1) cos^(2)60^(@)= (I_(0))/(2) xx ((1)/(2))^(2)= (I_(0))/(8)`
Intensity after 3rd polaroid,
`I_(3)= I_(2) cos^(2)60^(@)= (I_(0))/(8) xx ((1)/(2))^(2)= (I_(0))/(32)`
Intensity after 4th polaroid,
`I_(4)= I_(3) cos^(2)60^(@)= (I_(0))/(32) xx ((1)/(2))^(2)= (I_(0))/(128)`
Intensity after 5th polaroid,
`I_(5)= I_(4) cos^(2)60^(@)= (I_(0))/(128) xx ((1)/(2))^(2)= (I_(0))/(512)`