Question

What do you understand by refraction of light ?

Answer 1

Refraction is the bending of light as it passes from one substance to another. Here the light ray passes from air to glass and back to air. The bending is caused by the differences in density between the two substance.

Answer 2

Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends thelight ray toward the normal to the boundary between the two media.