$A$ light ray is incident on a glass slab at an angle of incidence of $60^o$. If the angle between the reflected ray and the refracted ray is $90^o$,what is the refractive index of the glass slab?

Give the meaning of $n_{12}$.

The refractive indices of water and glass with respect to air are $1.2$ and $1.5$ respectively. The refractive index of glass with respect to water is

The speed of light in air is $3 \times 10^8 \, m/s$. What will be its speed in diamond,whose refractive index is $2.4$?

An initially parallel cylindrical beam travels in a medium of refractive index $\mu(I) = \mu_0 + \mu_2I$,where $\mu_0$ and $\mu_2$ are positive constants and $I$ is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius. As the beam enters the medium,it will:

$A$ light wave travels through three transparent materials of equal thickness. Rank in order,from the highest to lowest,the indices of refraction $n_1, n_2$ and $n_3$.