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QJEEM21Ph09d8: JEE Main 2021 Physics - Class 12 JEEM21Ph09d8 Solution: An unpolarised light beam is incident on the polarizer of a…

An unpolarised light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging from the analyzer is measured as 100 Lumens. Now, if the analyzer is rotated around the horizontal axis (direction of light) by 30 ∘^\circ in clockwise direction, the intensity of emerging light will be _________ Lumens.

Step-by-Step Verified Solution

Given, I0 = 100 lumens

When analyser is rotated through an angle θ\theta , the intensity of light will becomes

I = I0 cos2 θ\theta = 100 ×\times cos230 ∘^\circ

= 100 ×\times (32)2{\left( {{{\sqrt 3 } \over 2}} \right)^2} = 75 lumens

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