Two polaroids are crossed. If now one of them is rotated through `30^(@)` and unpolarised light of intensity `l_(0)` is incident on the first polaroid, then the intensity of transmitted light will be

Options

A. `I_(0)/4`
B. `(3I_(0))/4`
C. `(3I_(0))/8`
D. `I_(0)/8`

Answer

D

Explanation

Intensity of transmit light from one polaroid, `I_(1) = I_(0)/2`, Therefore, intensity of light transmitted from second polaroid.
`I_(2) = I_(1) cos^(2)theta`
`= I_(0)/2 cos^(2)(90^(@) - 30^(@))`
`I_(0)/2 cos^(2)60^(@) = I_(0)/2 xx (1/2)^(2) = I_(0)/8`