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) $2$
In a medium the wavelength becomes $\lambda/\mu$, and fringe width $\beta = \dfrac{\lambda D}{d}$ scales the same way: $\beta' = \dfrac{2.4}{1.2} = 2\,\mu$m.
Solution by Sreeraj P, M.Sc Physics