Q 12-09-231JEE MainJEE Main 2025 (3 Apr, Shift 2)Easy
A monochromatic light of frequency $5\times10^{14}\ \text{Hz}$ travelling through air is incident on a medium of refractive index $2$. The wavelength of the refracted light will be:
Answer: (A) $300\ \text{nm}$
The frequency does not change on refraction; the speed becomes $c/\mu$.
$$\lambda = \frac{c}{\mu f} = \frac{3\times10^8}{2\times5\times10^{14}} = 3\times10^{-7}\ \text{m} = 300\ \text{nm}$$
Solution by Sreeraj P, M.Sc Physics