Question

Explain the dispersion of white light by a glass prism using necessary figure.Answer the given questions in detail.

Answer 1

When white light is made to pass through a prism, a spectrum of seven colors is formed which shows that white light is a mixture of seven different colors. Prism only acts as a medium for the separation of the seven colors. When light falls on the glass prism, refractiontakes place. Since the wavelength of different components of light is different and the frequency is constant, each component gets deviated by a different angle due to the difference in velocity in the glass medium. The red color having the maximum wavelength deviates the least and forms the upper part of the spectrum whereas violet having the least wavelength deviates the most.

Answer 2

Dispersion is the phenomena of splitting of visible light into different colours.

When the white light enters from one face of the prism it starts to show a slight deviation and occurrence of colours. This is because the light gets deviated from that angle and starts to split into different colours.

When light leaves the prism, it is again deviated and at this point is completely scattered into different spectrum of colours.

The colours that we see are the result of the difference in angle of deviation of these colours.

The wavelength of Violet colour is low and red has the highest wavelength.

On exiting the prism we see colours in the order of VIBGYOR.