Three identical polaroids P₁, P₂ and P₃ are placed one after another. The pass axis of P₂ and P₃ are inclined at angle of 60° and 90° with respect to axis of P₁. The source has an intensity I₀. The intensity of light finally coming out is (a) I₀/2cos ² 30° cos ² 90° (b) I₀/2cos ² 60° cos ² 30° (c) I₀cos ² 60° cos ² 30° (d) zero

Answer: (b). After P₁: I₀/2; P₂ is at 60° to P₁: I₀/2cos ² 60° P₃ is at 90° - 60° = 30° to P₂: multiply by cos ² 30°. I = I₀/2cos ² 60°cos ² 30° So the answer is (b).

Three identical polaroids P₁, P₂ and P₃ are placed one after another… | MHT CET 2026 (16 Apr, Shift 2)

Q6MHT CET 2026 · 16 APR · SHIFT 2Medium

Polarisation

Three identical polaroids $P_1, P_2$ and $P_3$ are placed one after another. The pass axis of $P_2$ and $P_3$ are inclined at angle of $60^\circ$ and $90^\circ$ with respect to axis of $P_1$ . The source has an intensity $I_0$ . The intensity of light finally coming out is

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Answer: (b)

After $P_1$ : $I_0/2$ ; $P_2$ is at $60^\circ$ to $P_1$ : $\frac{I_0}{2}\cos^2 60^\circ$
$P_3$ is at $90^\circ - 60^\circ = 30^\circ$ to $P_2$ : multiply by $\cos^2 30^\circ$ .
$I = \frac{I_0}{2}\cos^2 60^\circ\cos^2 30^\circ$
So the answer is (b).

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Polarisation question from MHT CET 2026 (16 Apr, Shift 2)

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