The relation governing refraction of light from rarer to denser medium at a spherical refracting surface is

Discuss briefly refraction from rarer to denser medium at a concave spherical refracting surface.

Discuss refraction from denser to rerer medium at a convex spherical refracting surface.

Prove that (-mu_1)/(u)+(mu_2)/(v) = (mu_2 - mu_1)/( R) when refraction occurs from rarer to denser medium at a concave spherical refracting surface.

When light is refracted into a denser medium

When light passes from a denser medium to a rarer medium

When light travels from rarer to denser medium, the refracted ray is _______ the normal.