In Young's double slit experiment using monochromatic light of wavelength λ, the intensity of light at a point on the screen where path difference λ is K units. What is the intensity of light at a point where path difference is \(\frac{λ}{3}\)?

\(\frac{K}{4}\)

$\text{Path difference }= \lambda \Rightarrow \text{Phase difference } = 2\pi$

$ I =I_1 + I_1+2\sqrt{I_1 I_1}= 4I_1 = k$

$\text{Path difference }= \frac{\lambda}{3} \Rightarrow \text{Phase difference } = \frac{2\pi}{3} $

$I = I_1 + I_1 - \sqrt{I_1 I_1} = I_1 = \frac{k}{4}$