Question

Explain how will the power of a lens change when its surrounding medium is changed from air to water. Give the condition under which a convex lens will start working as a diverging lens by changing its surrounding medium. Show this phenomenon by drawing a ray diagram.

Answer 1

If the refractive index of a liquid can be greater than the lens then the concave lens would turn into the convex and vice versa.

The refractive index is referred as the ratio of velocity of the light in any vacuum to the velocity in any specified medium.

The refractive index can be termed as a dimensionless number which describes the speed of propagation of light.