Q 12-10-032JEE MainJEE Main 2026 (5 Apr, Shift 1)Easy
In Young's double slit experiment, the fringe width of the interference pattern produced on the screen is $2.4\,\mu$m. If the experiment is carried out in another medium having refractive index $1.2$, the fringe width will be ______ $\mu$m.
Answer: (B) $2$
Concept. In a medium $\lambda \to \dfrac{\lambda}{\mu}$, and $\beta \propto \lambda$.
Step 1. New width. $\dfrac{2.4}{1.2} = 2\ \mu$m.
Answer. $2$ (Option B).
Solution by Sreeraj P, M.Sc Physics
