Question

A beam of unpolarized light of intensity $I_0$ is passed through a polaroid $A$ and then through another polaroid $B$ which is oriented so that its principal plane makes an angle of 45$^{\circ}$ relative to that of $A$. The intensity of the emergent light is

• A. $I_0$
• B. $\frac{I_0}{2}$
• C. $\frac{I_0}{4}$
• D. $\frac{I_0}{8}$

Answer 1

Answer: (C)

$\frac{I_0}{4}$

Answer 2

Relation between intensities is $I_R=\big(\frac{I_0}{2}\big)cos^2 (45^\circ)$

$=\frac{I_0}{2} \times \frac{1}{2}=\frac{I_0}{4}$

Therefore, The correct answer is (C) : $\frac{I_0}{4}$