$A$ ray of light is incident at an angle of $9.3^{\circ}$ on one face of a small-angle prism with a refracting angle of $6^{\circ}$. If the ray of light emerges normally from the second face, the refractive index of the material of the prism is:

One of the refractive surfaces of a prism of angle $30^{\circ}$ is silvered. $A$ ray of light incident at an angle of $60^{\circ}$ retraces its path. The refractive index of the material of the prism is:

$A$ prism of angle $A=1^{\circ}$ has a refractive index $\mu=1.5$. $A$ good estimate for the minimum angle of deviation (in degrees) is close to $N/10$. The value of $N$ is......

$A$ light ray is incident by grazing one of the faces of a prism. After refraction,the ray does not emerge out from the other face. What should be the angle of the prism if the critical angle is $C$?

The angle of minimum deviation for a prism of refractive index $1.5$ is equal to the angle of the prism. The angle of the prism is.......$^o$ (Given: $\cos 41^o = 0.75$)

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