Question

⦁ Why does ray of light splits when passed from prism?

Answer 1

Because each part of the light (i.e. the colors ) have their individual wavelength. each of these colors have their own velocity, here they come out of the prism, at different times and angles.
Hence the light splits up.
This phenomenon is also known as Dispersion.

Answer 2

The dispersion (splitting) of white light take place when it passes through the prism because the wavelength and angle of refraction of lights of different colours is different while passing through the transparent medium. For example, red colour deviates least and is formed at the upper part of the spectrum and violet colour is deviated maximum and is formed at the bottom of the spectrum.