Question

When white light splits in seven colours, the phenomenon is called spectrum.
A.) True
B.) False

Answer 1

Hint: To answer this problem, we need to understand the process of breaking white light into and the explanation behind its constituent colour.

Complete step-by-step answer:
As a tiny white light beam passes through a triangular glass prism, it breaks into a seven-colour band. Violet, Indigo, Blue, Green, Yellow, Orange and Red are the seven colours.
The colour series with the name VIBGYOR can be remembered.

The red colour with a longer wavelength is at least deviated, while the violet colour with a shorter wavelength is most deviated.

Upon passing through a refracting medium, the effect of breaking white light into its component colours is called Dispersion of light. Coloured band pattern produced on the computer is called spectrum.

Sir Isaac Newton was the first person to use a glass prism to absorb the sunlight.

Cause of dispersion of white light- Light rays of different colours fly at the same speed in vacuum. But lights of different colours fly with varying speeds in refracting mediums like glass, water, etc. Violet colour speed is the least although red colour speed is the highest in glass. The refractive glass index is thus the highest for violet colour, and the least for red colour. The violet colour is most deviated while going through the prism while the red colour is least deviated. Intermediate angles deviate from other colours. Through going through a glass prism, various component colours of white light are distributed.

Hence our answer is False as Spectrum is the coloured band pattern produced on the projector by separating white light into its constituent colours. And the separation of white light into its constituent colour is known as light dispersion.

Note: We must remember this property for answering such a type of question. The phenomenon of splitting white light into its component colours while moving through a refractory medium is called Light dispersion. The pattern of the coloured bands obtained on the screen is called spectrum.