Explain the cause of dispersion of white light through a prism

Asked by AMIT | 25th Mar, 2017, 12:17: AM

Expert Answer:

A prism is made up of a material like glass whose refractive index is greater than 1. Now, when a ray of light is incident on the prism, it gets refracted because its speed decreases in the glass. However, speed also depends on the wavelength of the light. Hence, different coloured lights are deviated through different angles as each colour is associated with different speeds, and hence, different refractive index. This is what causes dispersion of light. White light splits into seven colours because of dispersion.

Answered by Romal Bhansali | 26th Mar, 2017, 10:55: AM