$A$ certain prism is found to produce a minimum deviation of $38^{\circ}$. It produces a deviation of $44^{\circ}$ when the angle of incidence is either $42^{\circ}$ or $62^{\circ}$. What is the angle of incidence when it is undergoing minimum deviation (in $^{\circ}$)?

The prism angle of a prism is $40^{\circ}$. $A$ light ray is incident at $38^{\circ}$ and undergoes minimum deviation. The angle of minimum deviation is ........$^{\circ}$.

$A$ ray of light passes through an equilateral prism $(\mu = 1.5)$ such that the angle of incidence is equal to the angle of emergence,and the latter is equal to $3/4$ of the prism angle. The angle of deviation is.......$^o$

$A$ ray of light is incident at an angle of $60^{\circ}$ on the first face of a prism. The angle of the prism is $30^{\circ}$ and its second face is silvered. If the light ray inside the prism retraces its path after reflection from the second face, then the refractive index of the material of the prism is

$A$ prism is made of glass of unknown refractive index. $A$ parallel beam of light is incident on a face of the prism. The angle of minimum deviation is measured to be $40^{\circ}$. What is the refractive index of the material of the prism? The refracting angle of the prism is $60^{\circ}$. If the prism is placed in water (refractive index $1.33$),predict the new angle of minimum deviation of a parallel beam of light.

Derive the expression $\delta = i + e - A$ for a prism.