Chapter 12, Problem 21STP

To determine

To explain: if the light travels from water to glass under what condition 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.

Total internal reflection will not take place unless the incident light is travelling from denser medium to a rarer medium. The refractive index of glass is 1.52 and that of water is 1.33. The only way for the angle of refraction to be greater than angle of incidence is for light to bend away from the normal and light bends from normal while travelling from denser to rarer medium. Hence, total internal reflection will not occur for light travelling from water to glass.

Conclusion:

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