Optics Question 1150
Question: In Young double slit experiment, when two light waves form third minimum, they have
[RPMT 2003]
Options:
A) Phase difference of $ 3\pi $
B) Phase difference of $ \frac{5\pi }{2} $
C) Path difference of $ 3\lambda $
D) Path difference of $ \frac{5\lambda }{2} $
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Answer:
Correct Answer: D
Solution:
For minima, path difference $ \Delta =(2n-1)\frac{\lambda }{2} $
For third minima $ n=3\Rightarrow \Delta =(2\times 3-1)\frac{\lambda }{2}=\frac{5\lambda }{2} $