Chapter 18.2, Problem 32SSC

To determine

To Sketch:the effect of the air lens on parallel light rays that are incident on the lens.

Explanation of Solution

Introduction:

When a light rays travels from one medium to another medium, the light ray bends either towards or away from the interface of the two mediums. This measure of the bending of light ray when it enters from one medium to another is called as index of refraction.

Greater the value of index of refraction of a material, higher will be bending of light entering the material.

The index of refraction for air is $n=1.0$ and water is $n=1.3$ .

Greater the refractive index of the entering medium of light, slower will be speed of the light in that medium resulting in lesser bending of the light.

On the other hand, lesser the refractive index of the entering medium of light, quicker will be speed of the light in that medium resulting in more bending of the light.

When the light enters from the water into the air lens, the bending of light will be lesser in the air lens as the refractive index of the air lens is lesser than that of the surrounding water.

When the light enters from the air lens enters into the water, the bending of light will be more in the water medium as the refractive index of the water medium is more than that of the air lens.

Sketch the effect of air lens on parallel light rays incident on the lens as follows: