What occurs when light passes from one medium to another?

• A. Reflection
• B. Diffraction
• C. Refraction
• D. Absorption

Answer: (C)

When light passes from one medium to another, it undergoes refraction. Refraction is the bending of light as it enters a medium with a different density or refractive index. This bending occurs because the speed of light changes when it moves between materials, such as from air into water or from glass into air. The change in speed leads to a change in direction, resulting in the light being refracted.

For example, when a beam of light hits the surface of water at an angle, it slows down and bends as it moves from the less dense medium (air) to the more dense medium (water). This phenomenon is responsible for various optical effects, such as the apparent bending of a straw in a glass of water or the formation of rainbows.

Understanding refraction is essential in fields such as optics, photography, and even in the design of lenses, where controlling the path of light is crucial for achieving the desired effects.