\(32\,Wm ^{-2}\) તીવ્રતાનો અધ્રુવીભૂત પ્રકાશ ત્રણ પોલેરોઇડના સંયોજનમાંથી એવી રીતે પસાર થાય છે કે જેથી છેલ્લા પોલેરોઈડની દગ-અક્ષ પ્રથમ પોલેરોઈડની દગ-અક્ષને લંબ થાય. જો નિર્ગમન પામતા પ્રકાશની તીવ્રતા \(3\,Wm ^{-2}\) હોય, તો પ્રથમ બે પોલેરોઇડની દગ-અક્ષો વચ્યેનો કોણ ....... \(^{\circ}\) છે.

A \(20\)
B \(40\)
C \(90\)
D \(30\)

Verified Solution

Answer & Solution

Correct Answer

(D) \(30\)

Step-by-step Solution

Detailed explanation

\(I _{\text {net }}=3=\frac{32}{2} \cos ^2 \theta \cdot \sin ^2 \theta\) \(\frac{3}{4}=4 \sin ^2 \theta \cdot \cos ^2 \theta=(\sin 2 \theta)^2\) \(\frac{\sqrt{3}}{2}=\sin (2 \theta)\) Hence, \(\theta=30^{\circ}\) and \(60^{\circ}\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

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