How does the dispersion of white light take place when it passes through a glass prism ?

Explanation

When rays of light are incident on a prism, they are refracted twice, while travelling from air to glass and then from glass to air. Even when the incident rays are directed away from the base of the prism, the emergent rays bend towards the base of the prism, as the prism is triangular . Thus, the rays are deviated as they pass through the prism.
The refractive index of glass is different for different colours.Therefore, the rays corresponding to different colours are deviated to different extents. White light is a mixture of seven colours `:` violet, indigo, blue, green, yellow, orange and red. Hence, when white light is incident on a prism, a spectrum of seven colours is obtained.
The refractive index of glass is maximum for violet light and minimum for red light . Hence, violet light is deviated the most and red light is deviated the least. The deviation of rays corresponding to other colours is intermediate. In this manner, the dispersion of light takes place when it passes through a glass prism.