NEET UGPhysicsModerateNEET 2025

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at 22.5° from the polarization axis of one of the polaroids, is ( $I_0$ is the intensity of polarised light after passing through the first polaroid):

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Sol. <image_1>

I_1 = I_0 \cos^2 \left(\frac{45}{2}\right)

I_2 = I_1 \cos^2 \left(90-\frac{45}{2}\right)

= I_0 \cos^2 \left(\frac{45}{2}\right) \sin^2 \left(\frac{45}{2}\right)

= \frac{I_0}{4} \left(4 \cos^2 \left(\frac{45}{2}\right) \sin^2 \left(\frac{45}{2}\right)\right)

= \frac{I_0}{4} \sin^2 45^\circ = \frac{I_0}{8}

Source: geekyrakshit/indian-exam-questions / neet2025-code45

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