JEE Mains · Physics · STD 12 - Wave optics
- JEE Mains 2020
- Medium
- Numerical
A Young's doublc\(-\)slit experiment is performed using monochromatic light of wavelength \(\lambda\). The intensity of light at a point on the screen, where the path difference is \(\lambda,\) is \(K\) units. The intensity of light at a point where the path difference is A \(\frac{\lambda}{6}\) is given by \(\frac{n K}{12},\) where \(n\) is an integer. The value of \(n\) is\(......\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(9\)
Step-by-step Solution
Detailed explanation
\(I _{\max }= k\)
\(I _{1}= I _{2}= K / 4\)
\(\Delta x =\lambda / 6 \Rightarrow \Delta \phi=\pi / 3\)
\(I = I _{1}+ I _{2}+2 \sqrt{ I _{1} I _{2}} \cos \phi\)
\(I =\frac{ K }{4}+\frac{ K }{4}+2 \times \frac{ K }{4} \frac{1}{2}\)
\(=\frac{ K }{2}+\frac{ K }{4}=\frac{3 K }{4}=\frac{9 K }{12}\)
\(n =9\)
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