Define dispersion and spectrum....

Dear Student,

Dispersion:
The phenomenon of splitting up of white light into its constituent colours is known as dispersion. 

For example, 

When light passes through one face of a prism it gets deviated.

 This deviation is different for different wavelengths of light. Since different colours of light have different wavelength, the deviation for each colour is different.Red colour, having the longest wavelength suffers least deviation and violet, having the shortest wavelength suffers the highest deviation. As a result, when the light emerges from the other face of the prism we observe the individual seven constituent colours of light.This phenomenon of splitting of light into its constituent colours is called dispersion.

Spectrum:

When a beam of white light is passed through a prism, it gets split into a band of seven colours. This band of seven colours is known as spectrum.It comprises of violet, indigo, blue, green, yellow, orange and red commonly known as VIBGYOR.

The colours are arranged in the increasing order of wavelength.



Regards.