Chapter 12, Problem 40R

To determine

To find the event that describes why prism separates white light into seven colours.

1. Interference
2. Fluorescence
3. Diffraction
4. Refraction

Answer to Problem 40R

Option d is the correct answer.

Explanation of Solution

Introduction: The type of wave carrying energy through matter and/or space is known as light. Light waves carry radiant energy.

Prism is a structure which is three-dimensional and has two faces namely parallel and congruent.

When a white light is passed through a triangular prism, it refracts light two times. Firstly, when the light enters the prism and secondly when the light leaves the prism or re-enters the air. The wavelength of light has a smaller index of refraction because of longer wavelength, so it is refracted less than a shorter wavelength. Hence option (d) is correct.

Option a is incorrect. Interference is a pattern which occurs when two waves are superimposed.

Option b is incorrect. Fluorescent light is light produced by using phosphorus to convert UV radiations to visible light. Fluorescence can be seen with the human eye.

Option c is incorrect. If the size of the wavelength of a wave is same as the side of any object through which a wave is being diffracted, then diffraction is noticeable.

Conclusion: Hence, when white light enters a prism, each colour of light is bent a different amount and white light will split into the different colours of light.