Find the intensity at a point on a screen in Young’s double slit experiment where the interfering waves of equal intensity have a path difference of (i) $\lambda/4$, and (ii) $\lambda/3$.
CBSE FOREIGN - SET 2 2017
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Path difference ?/4 ⟹ phase difference ?/2
Path difference ?/3 ⟹ phase difference (2?/3)
$I=4I_0\cos^2\Big(\frac{\theta}{2}\Big)$
  1. $I_1=4I_0\times\frac{1}{2}=2I_0$
  2. $I_2=4I_0\times\frac{1}{4}=I_0$
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