Question

What is meant by dispersion of white light? Describe the formation of rainbow in the sky with the help of a diagram.

Answer 1

The splitting of white light into seven colours on passing through a transparent glass prism is called dispersion of white light.

A rainbow is formed in the sky because of the dispersion of sunlight by millions of water droplets in the atmosphere. Every single water droplet behaves like a tiny glass prism that splits the white light into different colours. Different colours bend at different angles on passing through the water droplets, thus separating the white light into a natural spectrum of seven colours, namely, violet, indigo, blue, green, yellow, orange and red. The diagram presented supports the above explanation and gives a clear picture about the formation of a rainbow.