question_answer

When an unpolarised light of intensity\[{{I}_{0}}\]is incident on a polarising sheet, the intensity of the light which does not get transmitted is -     AIEEE  Solved  Paper-2005

A) \[\frac{1}{2}{{l}_{0}}\]

B)        \[\frac{1}{4}{{l}_{0}}\]

C) zero      

D)        \[{{l}_{0}}\]

Correct Answer: A

Solution :

From Malus law, the intensity \[l={{l}_{0}}{{\cos }^{2}}\theta \] Intensity of polarised light \[=\frac{{{l}_{0}}}{2}\] Intensity of untransmitted light \[={{l}_{0}}-\frac{{{l}_{0}}}{2}\,=\frac{{{l}_{0}}}{2}\]