JEE Mains · Physics · STD 12 - Wave optics
- JEE Mains 2023
- Medium
- Numerical
As shown in figures, 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 \(S\) has an intensity of \(256 \frac{ W }{ m ^2}\). The intensity of light at point \(O\) is \(...........\frac{ W }{ m ^2}\).
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(24\)
Step-by-step Solution
Detailed explanation
By first polaroid \(P_1\) intensity will be halved then \(P_2\) and \(P_3\) will make intensity \(\cos ^2\left(60^{\circ}\right)\) and \(\cos ^2\left(30^{\circ}\right)\) times respectively.
\(\text { Intensity out }=\frac{256}{2} \times \frac{1}{4} \times\left(\frac{\sqrt{3}}{2}\right)^2=\frac{256 \times 3}{2 \times 4 \times 4}= 2 4\)
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