Question

explain rainbow with daigram

Answer 1

A rainbow is a natural spectrum appearing in the sky. It is caused by dispersion of sunlight by tiny droplets present in the atmosphere after a rainfall. The tiny droplets produce dispersion in the incident sunlight and then total internal reflection and then refraction, as shown. Due to these phenomenon, different colours reach the observer at different angles and a rainbow is formed.

Hope it may help you

Answer 2

$\textbf{Rainbow}$

It is a arc of seven colours produced in sky. Colours like violet, indigo, blue, green, yellow, orange, red. are the combination of colours which makes a rainbow. It is a natural spectra.

$\textbf{Formation}$

A water droplet acts like a prism. When a light enters that prism then it disperse the lights and undergoes refraction then internal reflection. And then again refraction.

When it comes out of the prism (water droplet) it is seems into seven colours. If an observer is standing there and these lights enters into his/her eyes then he/she saws a rainbow which is the combination of seven colours (colour discussed above).

To observe a rainbow :-

Sun must be behind us means the observer.

Rain must be recent.