Q 12-08-184JEE MainJEE Main 2020 (8 Jan, Shift 1)Easy
The critical angle of a medium for a specific wavelength, if the medium has relative permittivity $3$ and relative permeability $\dfrac43$ for this wavelength, will be:
Answer: (B) $30^\circ$
Refractive index $n = \sqrt{\varepsilon_r\mu_r} = \sqrt{3\times\tfrac43} = 2$.
$$\sin C = \frac1n = \frac12 \Rightarrow C = 30^\circ$$
Solution by Sreeraj P, M.Sc Physics