The refractive index of the material of a prism is sqrt2 and the angle of the prism is 30^@. One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface ) if its angle of incidence on the prism is

The refractive index of the material of a prism is sqrt2 and the angle

1.	The refractive index of the material of a prism is sqrt2 and the angle of the prism is 30^@. One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface ) if its angle of incidence on the prism is
Answer» `60^@` `45^@` zero `30^@` ANSWER :B