A ray of light enters a diamond (n=2) from air and is being internally reflected near the bottom as shown in the figure . Find the maximum value of angle `theta` possible.

A ray of light entering from air into a denser medium of refractive index (4)/(3) , as shown in figure The light ray suffers total internal reflection at the adjacent surface as shown. The maximum value of angle theta should be equal to :

A ray of light strikes an air-glass interface such that a part of it is reflected into air and the rest enters glass as shown in the figure below. If angle of refraction and refractive index of glass with respect to air is r and mu respectively,then value of alpha is

Find the angle theta_(a) made by the light ray when it gets refracted from water to air, as shown in figure.

A ray of light, travelling parallel to diameter of a sphere enters the sphere through a hole at point A as shown in the figure. The inner surface of the sphere is made perfectly reflecting. Find the number of reflections suffered by the ray before coming out of the sphere.