The angle of the prism is $30^o$. The rays incident at an angle of $60^o$ at one refracting face suffer a deviation of $30^o$. Then the angle of emergence is......$^o$

The angle of a prism is $60^{\circ}$ and the angle of minimum deviation is $30^{\circ}$. The angle of incidence is ........$^{\circ}$.

$A$ light ray is incident at an angle of $60^o$ on a prism of angle $45^o$. When the light ray emerges from the other surface at $90^o$ to the surface,the refractive index of the material of the prism $\mu$ and the angle of deviation $\delta$ are given by:

The glass prisms $P_{1}$ and $P_{2}$ are to be combined together to produce dispersion without deviation. The angles of the prisms $P_{1}$ and $P_{2}$ are selected as $4^{\circ}$ and $3^{\circ}$ respectively. If the refractive index of prism $P_{1}$ is $1.54,$ then that of $P_{2}$ will be

The refractive index of the material of a glass prism is $\sqrt{3}$. If the angle of minimum deviation is equal to the angle of the prism,then the angle of the prism is:
$\left(\cos 30^{\circ} = \frac{\sqrt{3}}{2} = \sin 60^{\circ}, \sin 30^{\circ} = \frac{1}{2} = \cos 60^{\circ}\right)$ (in $^{\circ}$)

$A$ thin prism $P_1$ with an angle $6^{\circ}$ and made of glass of refractive index $1.54$ is combined with another prism $P_2$ made from glass of refractive index $1.72$ to produce dispersion without average deviation. The angle of prism $P_2$ is $........{}^{\circ}$