$PQR$ is a right-angled prism with other angles as $60^o$ and $30^o$. The refractive index of the prism is $1.5$. $PQ$ has a thin layer of liquid. Light falls normally on the face $PR$. For total internal reflection at the face $PQ$,the maximum refractive index of the liquid is

Assertion: The refractive index of diamond is $\sqrt{6}$ and that of liquid is $\sqrt{3}$. If the light travels from diamond to the liquid,it will be totally internally reflected when the angle of incidence is $30^{\circ}$.
Reason: $\mu = \frac{1}{\sin C}$,where $\mu$ is the refractive index of diamond with respect to the liquid.

When a ray of light emerges from a block of glass,the critical angle is

Glass has refractive index $\mu$ with respect to air and the critical angle for a ray of light going from glass to air is $\theta$. If a ray of light is incident from air on the glass with angle of incidence $\theta$,the corresponding angle of refraction is:

The refractive index of glass is $\frac{3}{2}$ and that of water is $\frac{4}{3}$. The critical angle for a ray of light going from glass to water is

If light travels a distance $x$ in $t_1 \, s$ in air and $10x$ distance in $t_2 \, s$ in a medium,the critical angle of the medium will be