Two polaroids A and B are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now, another polaroid C is placed between A and B bisecting angle between them. If intensity of unpolarized light is I₀ then intensity of transmitted light after passing through polaroid B will be: (a) I₀/4 (b) I₀/8 (c) Zero (d) I₀/2

Answer: (b). C bisects the right angle between A and B, so it is at 45° to each. I = I₀/2cos ² 45°cos ² 45° = I₀/8 So the answer is (b) I₀/8.

Two polaroids A and B are placed in such a way that the pass-axis of… | JEE Main 2023 (31 Jan, Shift 1)

Q34JEE Main 2023 · 31 JAN · SHIFT 1Medium

Polarisation

Two polaroids $\mathrm{A}$ and $\mathrm{B}$ are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now, another polaroid $\mathrm{C}$ is placed between $\mathrm{A}$ and $\mathrm{B}$ bisecting angle between them. If intensity of unpolarized light is $\mathrm{I}_0$ then intensity of transmitted light after passing through polaroid $\mathrm{B}$ will be:

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Answer: (b)

C bisects the right angle between A and B, so it is at $45^\circ$ to each.
$I = \frac{I_0}{2}\cos^2 45^\circ\cos^2 45^\circ = \frac{I_0}{8}$
So the answer is (b) $\frac{I_0}{8}$ .

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Polarisation question from JEE Main 2023 (31 Jan, Shift 1)

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