A polaroid sheet is rotated between two crossed polarizers. The intensity of transmitted light would be maximum, when the angle between the axes of the first polarizer and the polaroid sheet is

π/4

The correct answer is Option (4) → π/4

For two crossed polarizers, the angle between their axes is $90^\circ$.

When a polaroid sheet is placed between them, the transmitted intensity is given by:

$I = I_0 \cos^2\theta \sin^2\theta = \frac{I_0}{4} \sin^2(2\theta)$

Intensity is maximum when, $\sin^2(2\theta) = 1$

⇒ $2\theta = 90^\circ$

⇒ $\theta = 45^\circ$

∴ The intensity of transmitted light is maximum when the angle between the axes of the first polarizer and the polaroid sheet is $45^\circ$.