Question

Dispersion of white light by a glass prism

Answer 1

Answer:

A glass prism refracts light rays at an angle and causes deviation of path of light rays. When white light (polychromatic light composed of the seven colours VIBGYOR) passes through the prism, refraction occurs. Since the refractive index varies according to the colour of light, the different monochromatic colours of light are refracted at different angles. Blue which has the shortest wavelength is refracted by the largest angle while red, with the longest wavelength, is refracted the least. Hence the emergent light rays of each colour have slightly different path leading to the splitting up of the light ray into the band of colours called the spectrum. This phenomenon is called dispersion.