Q 12-10-049JEE MainJEE Main 2025 (28 Jan, Shift 1)Easy
A double slit interference experiment performed with light of wavelength $600\ \text{nm}$ forms an interference fringe pattern on a screen with the $10^{\text{th}}$ bright fringe having its centre at a distance of $10\ \text{mm}$ from the central maximum. The distance of the centre of the same $10^{\text{th}}$ bright fringe from the central maximum when the source of light is replaced by another source of wavelength $660\ \text{nm}$ would be ______ mm.
Numerical value type. Enter your answer.
Answer: 11
The $n^{\text{th}}$ bright fringe is at $y_n = \dfrac{n\lambda D}{d} \propto \lambda$.
$$y' = 10\times\frac{660}{600} = 11\ \text{mm}$$
Solution by Sreeraj P, M.Sc Physics