JEE Mains · Physics · STD 12 - 10. Wave optics
The two light beams having intensities I and 9I interfere to produce a fringe pattern on a screen. The phase difference between the beams is \(\frac{\pi}{2}\) at point \(P\) and \(\pi\) at point \(Q\). Then the difference between the resultant intensities at \(P\) and \(Q\) will be.......\(I\)
- A \(2\)
- B \(6\)
- C \(5\)
- D \(7\)
Answer & Solution
Correct Answer
(B) \(6\)
Step-by-step Solution
Detailed explanation
\(I _{ P }= I +9 I +2 \sqrt{ I \times 9 I } \cos \frac{\pi}{2}\) \(I _{ P }=10\, I\) \(I _{ Q }= I +9 I +2 \sqrt{ I \times 9 I } \cos \pi\) \(=10 I -6 I =4 I\) \(\therefore I _{ P }- I _{ Q }=10 I -4 I =6 I\)
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