State the cause of dispersion when white light enters a glass prism. Explain with a diagram.

(N/A) The cause of dispersion is that white light is composed of different colours,each having a different wavelength.
When white light enters a glass prism,each colour travels at a different speed within the medium.
Because the refractive index of glass is different for different wavelengths,each colour bends through a different angle with respect to the incident ray.
Specifically,red light has the longest wavelength and bends the least,while violet light has the shortest wavelength and bends the most.
As a result,the rays of each colour emerge along different paths,becoming distinct and forming a band of colours known as a spectrum.
The diagram is as shown below: