RRB Group-D Model Paper 14 with answers for online practice

CONCEPT:

• Dispersion of light: The splitting of a composite beam of light into its constituent colours is called dispersion of light.
• The dispersion of white light occurs because the colours of white light travel at different speeds through the glass prism.
• The band of seven colours is known as the spectrum of light.
• The dispersion was discovered by Sir Issac Newton.
• Newton discovered that light is made up of seven different colours.

EXPLANATION:

• From the above, it is clear that Issac Newton was the first to use a glass prism to obtain the spectrum of sunlight. Therefore option 3 is correct.