The absolute refractive indices of water,glass,and diamond are $1.33$,$1.50$,and $2.42$ respectively. Which medium is the most optically dense?

When does Snell's law fail?

Define absolute refractive index. Absolute refractive indices of medium $A$ and medium $B$ are $n_{a}$ and $n_{b}$ respectively. What is the refractive index of medium $B$ with respect to medium $A$? How does the velocity of light vary with change in the optical density of the media?

The refractive indices of medium $(1)$ and medium $(2)$ are $\eta_{1}$ and $\eta_{2}$ respectively,and the velocities of light in these media are $v_{1}$ and $v_{2}$ respectively. What is the formula to find the refractive index of medium $(2)$ with respect to medium $(1)$,denoted as $\eta_{21}$?

You are given water,mustard oil,glycerine,and kerosene. In which of these media would a ray of light incident obliquely at the same angle bend the most?

What will be the angle of refraction for a light ray incident normally at the surface (in $^{\circ}$)?