Chapter 12, Problem 20STP

To determine

To explain: if the direction of light is reversed from air to water, under what circumstances will total internal reflection occur.

Explanation of Solution

Introduction:

Total internal reflection occurs if the light travels from a denser medium to a rarer medium. Again for total internal reflection to occur the angle of incidence should be greater than the critical angle.

When a light wave travels from air to water, a rarer to a denser medium then it does not fulfill the condition for total internal reflection. Total internal reflection will occur for light travelling from water to air but not from air to water.

Conclusion:

Thus, total internal reflections will not occur when light travels from air to water.