Physics - Wave Optics Question with Solution | TestHub

As given here, the pass axis of polaroids $A$ and $B$ are inclined at angle of  $90º$ with each other. Another polaroid $C$is placed at angle of $45°$with respect to $A$ and $B$. 

Therefore, intensity of light after falling on polaroid $A, I_A=\frac{I_0}{2}$

Intensity of light after falling on polaroid $C, I_C=I_A{\cos }^{2}45°=\frac{I_0}{2}{\cos }^{2}45°=\frac{I_0}{4}$

Intensity of light after falling on polaroid $B, I_B=I_C{\cos }^{2}45°=\frac{I_0}{4}{\cos }^{2}45°=\frac{I_0}{8}$