Dispersion of light

Explanation

The process of separation of light into its component colours while passing through a medium is called dispersion of light. When white light passes through a glass prism, it spreads out into a band of different colours ( componenets ) called the spectrum of light. The colours in the spectrum of white light are violet, indigo, blue, green, yellow, orange and red.
Formation of a rainbow is an example of dispersion of light in nature. In this case, raindrops are responsible for dispersion of sunlight.
Dispersion takes place because the refractive index of a material such as glass or water, is different for different colours. It is maximum for violet colour and minium for red colour. Hence, in the spectrum of white light ( sunlight ) obtained with a prism, violet light is deviated the most while red light is deviated the least. The deviation of light corresponding to other colours lies in between.