A polarizer analyzer set is adjusted such that the intensity of ligth coming out of the analyzer is just 10% of the original intensity. Assuming that the polarizer analyzer set does not asorb any light, the angle by which the analyzer needs to be rotated further to reduce the output intensity to be zero is

Options

A. `60^(@)`
B. `45^(@)`
C. `18.4^(@)`
D. `71.6^(@)`

Answer

C

Explanation

From Malus. law,
`I=I_(0) cos^(2) theta`
`0.1 I_(0)=I_(0)cos^(2) theta [ :. I=10% of I_(0)]`
`:. cos^(@) theta =0.1`
`:.cos theta=sqrt(0.1)`
`=cos theta=0.3162`
`:. Theta=71.6^(@)`
Angle of rotation `=90^(@)-theta`
`=90^(@)-theta`
`=18.4^(@)`