The angle of minimum deviation for a prism of refractive index $1.5$ is equal to the angle of the prism. The angle of the prism is . . . . . . . $(\sin 48^{\circ} 36^{\prime} = 0.75)$

$A$ deviation of $5^o$ is observed from a prism whose angle is small and whose refractive index is $1.5$. The angle of the prism is.......$^o$

The angle of a prism is $A$ and one of its refracting surfaces is silvered. Light rays falling at an angle of incidence '$2A$' on the first surface return back through the same path after suffering reflection at the silvered surface. The refractive index of the material of the prism is

$A$ ray of monochromatic light is passing through an equilateral prism $(ABC)$ as shown in the figure. The refracted ray $(QR)$ is parallel to its base $(BC)$ and the angle of incidence $(i)$ is $50^\circ$. Then the angle of deviation $(\delta)$ is: (in $^\circ$)

An isosceles glass prism with base angles $40^{\circ}$ is clamped over a tray of water in a position such that the base is just dipped in water. $A$ ray of light incident normally on the inclined face suffers total internal reflection at the base. If the refractive index of water is $1.33$,then the condition imposed on the refractive index $\mu$ of the glass is

$A$ prism has a refracting angle of $30^\circ$ and a refractive index of $\mu = \sqrt{2}$. One of its faces is silvered. $A$ ray of light incident on the other face retraces its path. What is the angle of incidence in degrees?