The distance travelled by light in glass (refractive index $= 1.5$) in a nanosecond will be.......$cm$.

The index of refraction of diamond is $2.0$. The velocity of light in diamond in $cm/s$ is approximately:

$A$ ray of light is incident at $30^{\circ}$ from a medium of refractive index $2$ into a medium of refractive index $1$. The angle of refraction is: (in $^{\circ}$)

$A$ ray of light travels from air to water to glass and again from glass to air. The refractive index of water with respect to air is $x$,glass with respect to water is $y$,and air with respect to glass is $z$. Which one of the following is correct?

When light travels from one medium to another with a different refractive index, which of the following will change?

The apparent depth of water in a cylindrical water tank of diameter $2R \ cm$ is reducing at the rate of $x \ cm/minute$ when water is being drained out at a constant rate. The amount of water drained in $c.c./minute$ is: ($n_1 =$ refractive index of air,$n_2 =$ refractive index of water)