How is the rainbow formed.

Hint:The reflection of light, refraction, and dispersion in the water droplets causes many optical phenomena. They give the spectrum of various colors of the light in the sky. The various colors are formed in the sky in a circular pattern.

Complete step by step answer:
The light coming from the sun with the water droplets forms the rainbow in the rainy condition. The lights strike on the water droplets' surface present in the atmosphere and reflect at some angle. Some portion of the unreflected light refracted as well as undergoes dispersion. The spectrum of sunlight in various colours occurs by reflection and it always occurs in the direction of the sun. This spectrum of colours is known as the rainbow. The various colors of the spectrum in the sky occur in the circular arc type pattern, and it is visible from various parts of the earth's surface. Due to the spherical shape of the water droplets, the generation circular pattern of the various colors takes place. In the formation of the rainbow, the reflection process is responsible for the circular pattern, and the refraction process is responsible for the various colors of the rainbow.

Note:Different colors of the spectrum deviate in different amounts according to the color's wavelength. The deviation of red color in the rainbow is least because its wavelength is more, whereas the blue color deviation in the rainbow is highest because its wavelength is highest. So, we can obtain information that the deviation of colors in the rainbow relates inversely with wavelength.