A ray of light incident in a medium of refractive index $\mu_{1}$, is partially reflected and refrac

Question

A ray of light incident in a medium of refractive index $\mu_{1}$, is partially reflected and refracted at the boundary of another medium of refractive index $\mu_{2}$. If the reflected and refracted rays are perpendicular to each other, then the angle of incidence must be\

Professor PC Thomas Classes · Answer

$90-\mathrm{i}+90-\mathrm{r}=90^{\circ}$\ \ $\mathrm{i}+\mathrm{r}=90^{\circ}$\ or $r=\left(90^{\circ}-iight)$\ $	herefore \frac{\mu_{2}}{\mu_{1}}=\frac{\sin \mathrm{i}}{\sin \mathrm{r}}$\ $=\frac{\sin \mathrm{i}}{\sin \left(90^{\circ}-\mathrm{i}ight)}=\frac{\sin \mathrm{i}}{\cos \mathrm{i}}$\ $	herefore \frac{\mu_{2}}{\mu_{1}}=	an i \Rightarrow i=	an ^{-1} \frac{\mu_{2}}{\mu_{1}}$\ (This is Brewster's law)\