Q. An unpolarised beam of intensity $I_{0}$ is incident on a pair of nicols making an angle of $60{^\circ}$ with each other. The intensity of light emerging from the pair is
A) $I_{0}$
B) $I_{0}/2$
C) $I_{0}/4$
D) $I_{0}/8$
Explanation
(c) According to Malus’ law
$I = I_{0}\cos^{2}\theta = I_{0}\ \left( \cos^{2}{60{^\circ}} \right) = I_{0} \times \left( \frac{1}{2} \right)^{2} = \frac{I_{0}}{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.