Prism and Spectrum Formation

Introduction:
When light passes through a prism, it undergoes a phenomenon known as dispersion, which leads to the formation of a spectrum. The property of light that is utilized by a prism to create a spectrum is refraction.

Refraction of Light:
Refraction is the bending of light as it passes from one medium to another. It occurs due to the change in the speed of light when it travels through different materials. The bending of light rays is caused by the change in the density of the medium, which leads to a change in the speed of light. The extent of bending depends on the angle of incidence and the refractive index of the material.

Prism:
A prism is a transparent object with two triangular ends and parallel rectangular sides. When light enters a prism, it undergoes refraction at each surface due to the change in the speed of light. The refractive index of the prism material determines the degree of bending. Different colors of light have different wavelengths, and each wavelength bends at a slightly different angle when passing through the prism.

Spectrum Formation:
The phenomenon of dispersion occurs when white light, which consists of a combination of all visible colors, passes through a prism. The different colors of light have different wavelengths, and as they pass through the prism, they refract at different angles. This causes the light to separate into its constituent colors, forming a spectrum.

Explanation:
1. Refraction: When light enters the prism, it refracts at each surface due to the change in the speed of light.
2. Dispersion: As the different colors of light have different wavelengths, they refract at different angles when passing through the prism.
3. Separation of Colors: The bending of light at different angles causes the colors to separate, forming a spectrum. The shorter wavelengths of light, such as violet and blue, refract more and deviate towards the base of the prism. On the other hand, longer wavelengths like red refract less and deviate towards the apex of the prism.
4. Spectrum Formation: The separated colors, ranging from violet to red, create a continuous band of colors known as a spectrum.

Conclusion:
In conclusion, the property of light that is used by a prism to form a spectrum is refraction. When white light passes through a prism, it refracts at different angles due to the varying wavelengths of light, causing the colors to separate and form a spectrum.

Dispersion of light