In Young's double slit experiment, distance between the slits $S_1$ and $S_2$ is d and the distance between slits and screen is D. Then first missing wavelength on the screen in front of $S_1$ is
Answer & explanation
Correct answer: option 1
Path difference, $Δx=\frac{d^2}{2D}$
For first missing wavelength,
$\frac{d^2}{2D}=\frac{λ}{2}$ or $λ=\frac{d^2}{D}$