Which of the following prisms is used to see the infrared spectrum of light?

$A$ plot between the angle of deviation and angle of incidence is shown in the figure. From the graph,one can say that the prism angle is ....... (in $^{\circ}$)

$A$ ray of light is incident normally on one of the faces of a prism of angle $30^\circ$ and refractive index $\sqrt{2}$. The angle of deviation will be.....$^\circ$

$A$ beam of monochromatic light is incident at $i = 50^{\circ}$ on one face of an equilateral prism. If the angle of emergence is $e = 40^{\circ}$,then the angle of minimum deviation $\delta_m$ is:

$A$ light ray is incident on a prism at an angle of $60^{\circ}$ and the refracting angle of the prism is $30^{\circ}$. The emergent ray makes an angle of $30^{\circ}$ with the incident ray. The refractive index of the prism is ...

The refracting angle of a prism is $A,$ and the refractive index of the material of the prism is $\cot(A/2).$ The angle of minimum deviation is: