Question

With the help of a ray diagram, explain any phenomenon of formation of spectrum in nature.

Answer 1

The formation of a rainbow is a natural phenomenon caused by the dispersion of sunlight by tiny water droplets present in the atmosphere.

When sunlight enters a raindrop, it:

1. Refracts and gets dispersed into its seven constituent colours (VIBGYOR).
2. Undergoes internal reflection inside the water droplet.
3. Refracts again while coming out, forming a spectrum (rainbow).

Thus, a rainbow is formed due to refraction, dispersion, and internal reflection of sunlight in water droplets.