$A$ beam of light both reflects and refracts at the surface between air and glass. The refractive index of the glass is $1.4$. If the refracted and the reflected rays are perpendicular to each other,then the angle of incidence in the air is

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 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,$\mu_{r}=1$)

Light is incident at an angle $i$ on a glass slab. The reflected ray is completely polarised. The angle of refraction is

The angle of incidence at which reflected light is totally polarized for reflection from air to glass (refractive index $n$) is

$A$ beam of light $AO$ is incident on a glass slab $(\mu = 1.54)$ in a direction as shown in the figure. The reflected ray $OB$ is passed through a Nicol prism. On viewing through the rotating Nicol prism,we find that $(\tan 57^{\circ} = 1.54)$.

The refractive index of a medium is equal to the tangent of the polarizing angle. This is known as: