The maximum refractive index of a material, of a prism of apex angle $90º$, for which light may be transmitted is:

A prism having an apex angle of $4°$ and refractive index of $1.50$ is located in front of a vertical plane mirror as shown in the figure. A horizontal ray of light is incident on the prism. The total angle through which the ray is deviated is: 

The image for the converging beam after refraction through the curved surface (in the given figure) is formed at:

In the given figure, a plano-concave lens is placed on a paper on which a flower is drawn. How far above its actual position does the flower appear to be?

A beam of diameter $d$ is incident on a glass hemisphere as shown in the figure. If the radius of curvature of the hemisphere is very large in comparison to $d$, then the diameter of the beam at the base of the hemisphere will be: