Why does dispersion occur when white light which is a mixture of seven colours passes through a glass prism?

Correct option is A

The correct answer is (a) 7 colours of white light travel at different speeds through a glass prism.
· Dispersion occurs when white light, which is a mixture of seven colours, passes through a glass prism because each colour in the light spectrum travels at a different speed through the glass.
· Different colours of light have different wavelengths, and their speed changes as they pass from one medium (air) into another medium (glass). This change in speed causes each colour to bend or refract by a different amount.
· Violet light (shortest wavelength) slows down the most and bends the most, while red light (longest wavelength) slows down the least and bends the least. This separation of colours is what we see as the spectrum of light.
· As a result, the white light disperses into its constituent colours, creating a visible spectrum ranging from red to violet.
Information Booster:
· Refraction: The bending of light as it passes from one medium to another with a different density. The amount of bending depends on the refractive index of the material and the wavelength of the light.
· Refractive Index: Different colours have different refractive indices in a medium like glass, which causes them to refract at different angles.
· Reflection vs. Refraction: Reflection involves light bouncing off a surface, while refraction involves light bending as it passes through a material.