What is the dispersion of light? Which are the colours of the spectrum obtained from the dispersion through a glass prism?

Dispersion is the natural phenomenon by which white light is split into seven constituent colours. The band of the seven colours obtained from the splitting of white light is called spectrum. All the constituents of white light travelling in vacuum they have the same velocity but when they pass through a transparent medium their velocity changes and they tend to deviate.

Fig. Dispersion of white light by a prism

The colour spectrum obtained from the dispersion of white light are:

Ø V – Violet

Ø I – Indigo

Ø B – Blue

Ø G – Green

Ø Y – Yellow

Ø O – Orange

Ø R - Red