Which phenomenon causes the dispersion of light?

• A. Reflection in water
• B. Diffraction through a slit
• C. Refraction in a prism
• D. Absorption by a filter

Answer: (C)

Dispersion of light occurs when light is separated into its constituent colors due to the phenomenon of refraction. When light passes through a prism, it changes speed as it moves from one medium (air) into another medium (glass), which causes the light to bend. Different colors (frequencies) of light bend at slightly different angles due to their varying wavelengths. This results in the spectrum of colors being spread out, which is seen in the rainbow effect when white light passes through a prism.

This understanding of dispersion is crucial in many optical applications, including the design of prisms, lenses, and various optical instruments. By manipulating how light is refracted through different materials, we can effectively separate and analyze light's properties. Thus, the process of refraction in a prism is directly responsible for the phenomenon of light dispersion, making it the correct answer.