Q 12-09-223NEETNEET 2022Top questionEasy
Two transparent media $A$ and $B$ are separated by a plane boundary. The speed of light in those media are $1.5 \times 10^8$ m/s and $2.0 \times 10^8$ m/s, respectively. The critical angle for a ray of light for these two media is
Answer: (C) $\sin^{-1}(0.750)$
Light is slower in $A$, so $A$ is the denser medium; total internal reflection happens for light going from $A$ to $B$.
$$\sin C = \frac{\mu_B}{\mu_A} = \frac{v_A}{v_B} = \frac{1.5 \times 10^8}{2.0 \times 10^8} = 0.75$$
$C = \sin^{-1}(0.750)$.
Solution by Sreeraj P, M.Sc Physics