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 $^{\circ}$)

$A$ light ray enters through a right-angled prism at point $P$ with an angle of incidence of $30^{\circ}$ as shown in the figure. It travels through the prism parallel to its base $BC$ and emerges along the face $AC$. The refractive index of the prism is:

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

For a thin prism,if the angle of prism is $4^{\circ}$ and the refractive index is $1.6$,then the angle of minimum deviation will be . . . . . . . (in $^{\circ}$)

$A$ thin prism $P_{1}$ with angle $4^{\circ}$ and made from glass of refractive index $1.54$ is combined with another thin prism $P_{2}$ made from glass of refractive index $1.72$ to produce dispersion without deviation. The angle of prism for $P_{2}$ is (in $^{\circ}$)

$A$ ray of light is incident on an equilateral glass prism placed on a horizontal table. For minimum deviation,which of the following is true?