Question

An unpolarized beam of light of intensity $I_0$ passes through two linear polarizers making an angle of ${30}^o$ with respect to each other. The emergent beam will have an intensity

• A. $\frac{3I_0}{4}$
• B. $\frac{\sqrt{3}{I}_0}{4}$
• C. $\frac{3I_0}{8}$
• D. $\frac{I_0}{8}$

Answer 1

The correct option is A $\frac{3I_0}{4}$

Angle between the polarizers $\theta ={30}^o$.

From Malus's law, intensity of emergent beam $I=I_o{\cos }^2\theta$

$\therefore$ $I=I_o\times (\frac{\sqrt{3}}{2}{)}^2$

$⟹$ $I=\frac{3I_o}{4}$