Physics 2010 JAMB Past Questions - Question 32: Dispersion occurs when white light passes through a glass prism because of the

Correct Answer

A

Explanation

Dispersion occurs when white light passes through a glass prism due to the phenomenon of refraction and the fact that different colors of light have different wavelengths. When white light, which is a mixture of all the colors of the visible spectrum, enters a prism, it slows down and bends as it passes from air into the denser glass medium. This bending of light is known as refraction.

The key reason for dispersion in a prism is that the amount of bending (or the angle of refraction) depends on the wavelength of light. Different colors of light have different wavelengths, with red light having longer wavelengths and blue/violet light having shorter wavelengths. As a result, each color is refracted by a different amount, with blue/violet light being refracted the most and red light the least.

The dispersion of white light in a prism causes the different colors to spread out or separate from each other, forming a spectrum of colors, with red on one end and violet on the other. This separation of colors is what we commonly refer to as a rainbow. This phenomenon is also responsible for the colorful patterns you might see in a glass prism or in a crystal chandelier, where the different colors of light are separated and create beautiful spectral patterns.