Question
Unpolarised light is incident on the boundary between two dielectric media, whose dielectric constants are $2.8$ (medium -1) and $6.8$ (medium $2)$, respectively. To satisfy the condition, so that the reflected and refracted rays are perpendicular to each other, the angle of incidence should be $\tan ^{-1}\left(1+\frac{10}{\theta}\right)^{\frac{1}{2}}$ the value of $\theta$ is $.............$ (Given for dielectric media, $\mu_{ r }=1$ )
