Chapter 24, Problem 26Q

To determine

To explain: The index of refraction of the oil.

Explanation of Solution

Introduction:

When a ray of light is passing from one medium to another medium, then the measurement of the bending of the light ray can be defined as refractive index or index of refraction.

The film is very thin at the edges of the oil drop, so there will be no path difference between the upper and lower part of the oil drop resulting in the same phase change. As we know that the refractive index of oil is greater than the refractive index of air, so the phase change between the two portions is $180°$ . Now, lower portion of the oil drop is in contact with water. Hence, it proves that refractive index of water is greater than the refractive index of oil.

So, the index of refraction of oil is less than that of water and greater than that of air.

Conclusion:

Hence, the index of refraction of oil is: $1.33>n>1.00$