Introduction:
When white light passes through a prism, it separates into different colors, creating a spectrum. This phenomenon occurs due to the refraction and dispersion of light. The deviation of different colored rays in a prism can be explained by considering the following factors:

Refraction:
Refraction is the bending of light as it passes from one medium to another. When light enters a prism, it undergoes refraction at each boundary between the air and the prism material. This refraction causes the light rays to change direction, and the degree of bending depends on the wavelength of light.

Dispersion:
Dispersion is the process by which white light separates into its constituent colors. Different colors of light have different wavelengths, and as a result, they refract at different angles when passing through a prism. This is due to the phenomenon of chromatic dispersion.

Chromatic Dispersion:
Chromatic dispersion occurs because the refractive index of a material depends on the wavelength of light. In a prism, the refractive index is higher for shorter wavelengths (violet light) and lower for longer wavelengths (red light). As a result, the different colors of light deviate at different angles when passing through the prism.

Angular Dispersion:
Angular dispersion refers to the separation of different colors of light by their angles of deviation. Since the refractive index varies with wavelength, the angle of deviation also varies. Violet light, with the shortest wavelength, is refracted the most and deviates the most from the original path. On the other hand, red light, with the longest wavelength, is refracted the least and deviates the least.

Explanation:
When white light enters a prism, it is refracted twice - once when entering the prism and again when leaving it. The different colors of light deviate at different angles during these refractions, leading to the separation of colors. Violet light deviates the most, followed by blue, green, yellow, orange, and finally red.

Conclusion:
In conclusion, different colored rays deviate differently in a prism due to the phenomenon of chromatic dispersion. The refractive index of a material varies with the wavelength of light, causing the different colors to refract at different angles. This angular dispersion results in the separation of colors, creating the beautiful spectrum we observe when white light passes through a prism.

Different colors deviate at different angles when passing through a prism because different colors have different wavelength due to which they travel through the glass with different speeds and hence glass has the different refractive index for different colors.