$A$ ray of light passing through an equilateral prism has a velocity of $2.12 \times 10^8 \text{ m/s}$ in the prism material. The minimum angle of deviation is . . . . . . degrees.

The figure shows the graph of the angle of deviation $\delta$ versus the angle of incidence $i$ for a light ray striking a prism. The prism angle $A$ is: (in $^{\circ}$)

The critical angle between an equilateral prism and air is $45^o$. If the incident ray is perpendicular to the refracting surface,then

$A$ 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.

For refraction through a small angled prism,the angle of deviation:

$A$ ray falls on a prism $ABC$ $(AB = BC)$ and travels as shown in the figure. The minimum refractive index of the prism material should be