Find the final intensity of light $\left(I^{\prime \prime}\right)$, if the angle between the axes of

Question

Find the final intensity of light $\left(I^{\prime \prime}\right)$, if the angle between the axes of two polaroids is $60^{\circ}$.

Professor PC Thomas Classes · Answer

From first polaroid the unpolarised light will become polarized with half the intensity.
So, $I^{\prime}=\frac{I_0}{2}$
From second polaroid
$
I^{\prime \prime}=I^{\prime} \cos ^2 	heta=\frac{I_0}{2} \cos ^2(60)=\frac{I_0}{2} \quad \frac{1}{4}=\frac{I_0}{8}
$