One of the necessary conditions for total internal reflection to take place is ($i =$ angle of incidence,$i_{c} =$ critical angle).

Light travels a distance $x$ in time $t_1$ in air and $10x$ in time $t_2$ in another denser medium. What is the critical angle for this medium?

$A$ glass prism of refractive index $1.5$ is immersed in water (refractive index $\frac{4}{3}$) as shown in the figure. $A$ light beam incident normally on the face $AB$ is totally internally reflected at the face $AC$ to reach the face $BC$,if:

Calculate the critical angle for a glass-air surface,if a ray of light incident in air on the glass surface is deviated by $15^{\circ}$ when the angle of incidence is $45^{\circ}$. (in $^{\circ}$)

The refractive indices of the material of the prism and the liquid are $1.56$ and $1.32$ respectively. Find the value of $\theta$ for total internal reflection at the interface.

The critical angle for total internal reflection of light going from medium $I$ to medium $II$ is given by the relation $\tan i_C = \frac{5}{9}$. The refractive index of medium $I$ with respect to medium $II$ is: