Q 12-10-061JEE MainJEE Main 2024 (27 Jan, Shift 2)Easy
When a polaroid sheet is rotated between two crossed polaroids, then the transmitted light intensity will be maximum for a rotation of:
Answer: (D) $45^\circ$
If the middle sheet makes angle $\theta$ with the first polaroid, it makes $90^\circ - \theta$ with the second:
$$I = \frac{I_0}{2}\cos^2\theta\sin^2\theta = \frac{I_0}{8}\sin^2 2\theta$$
This is maximum when $2\theta = 90^\circ$, i.e. $\theta = 45^\circ$.
Solution by Sreeraj P, M.Sc Physics