Question

‘A rainbow is the combined effect of refraction, dispersion and total internal reflection of light’. Explain the sentence.

Answer 1

• A rainbow is formed when sunlight passes through tiny water droplets in the atmosphere.
• The light first undergoes refraction and bends as it enters the droplet.
• It then gets dispersed into its constituent colours because different colours bend by different amounts.
• Inside the droplet, the light undergoes total internal reflection at the inner surface.
• Finally, the light refracts again as it comes out of the droplet, and the different colours emerge at different angles to form a rainbow.