Question

A polarized light of intensity $I_o$ is passed through another polarizer whose pass axis makes an angle of ${60}^o$ with the pass axis of the former. What is the intensity of emergent polarized light from second polarizer?

• A. $I=I_o$
• B. $I=I_o/6$
• C. $I=I_o/5$
• D. $I=I_o/4$

Answer 1

The correct option is D $I=I_o/4$

Given : $\theta ={60}^o$

From Malus's law, intensity of emergent polarised light $I=I_{o}co{s}^2\theta$

$\therefore$ $I=I_o{\cos }^2{60}^o$

$⟹$ $I=I_o/4$ $(\because \cos {60}^o=1/2)$