JEE Mains · Physics · STD 12 - 10. Wave optics
A beam of plane polarised light of large cross sectional area and uniform intensity of \(3.3 \,Wm ^{-2}\) falls normally on a polariser (cross sectional area \(3 \times 10^{-4}\, m ^{2}\) ) which rotates about its axis with an angular speed of \(31.4\, rad/s.\) The energy of light passing through the polariser per revolution, is close to ........ \( \times 10^{-4} \,J\)
- A \(0.1\)
- B \(5\)
- C \(1\)
- D \(1.5\)
Answer & Solution
Correct Answer
(C) \(1\)
Step-by-step Solution
Detailed explanation
Intensity, \(I=3.3 Wm ^{-2}\) Area, \(A=3 \times 10^{-4} m ^{2}\) Angular speed, \(\omega=31.4 rad / s\) \(T=\frac{2 \pi}{\omega}\) \(I = I _{0} \cos ^{2} \omega t\) \(\because \cos ^{2} \theta =\frac{1}{2},\) in one time period \(I=\frac{E}{A\cdot t}\) \(\therefore\) Average…
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