Answer the following:

What is dispersion of light?

The dispersion of light is the phenomenon of splitting of a beam of white light into its seven constituent colours when passed through a transparent medium. It was discovered by Isaac Newton in 1666.

Cause of dispersion of light is that white light consists of seven different colors, and each colour has a different angle of deviation. Therefore, on passing through the prism different colours deviate from different angles.

Hence the seven colours of white light separate and form a spectrum. Out of the seven colours, the red colour deviates the least, and the violet colour deviates most. The figure below shows the spectrum of white light after passing it through the prism.