In the diagram,the ray passing through the prism is parallel to the base. The refractive index of the material of the prism is:

For a prism with a prism angle of $60^\circ$ and a refractive index of $\mu = \sqrt{2}$,the angle of minimum deviation is .......... $^\circ$.

One face of the glass prism is silver polished. $A$ light ray falls at an angle of $45^{\circ}$ on the other face. After refraction,it is subsequently reflected from the silvered face and then retraces its path. The refracting angle of the prism is $30^{\circ}$. The refractive index of the prism is

$A$ ray of light is incident at an angle of $60^{\circ}$ on the first face of a prism. The angle of the prism is $30^{\circ}$ and its second face is silvered. If the light ray inside the prism retraces its path after reflection from the second face, then the refractive index of the material of the prism is

An isosceles prism of angle $A=30^{\circ}$ has one of its surfaces silvered. Light rays falling at an angle of incidence $60^{\circ}$ on the other surface retrace their path after reflection from the silvered surface. The refractive index of the prism material is

The minimum deviation produced by a hollow prism filled with a certain liquid is found to be $30^{\circ}$. The light ray is also found to be refracted at an angle of $30^{\circ}$. Then the refractive index of the liquid is