Refraction occurs under which description?

Refraction occurs under which description?

• A. Refraction occurs when waves bounce off a boundary.
• B. Refraction occurs when waves change speed as they pass into a different medium, causing bending.
• C. Refraction occurs only for sound waves.
• D. Refraction causes waves to stop at the boundary.

Answer: (B)

Refraction happens because a wave changes speed when it enters a different medium, and that change in speed makes the wave bend as it crosses the boundary. When light (or any wave) moves from one material to another, the part of the wave that enters the new medium changes speed, so its path tilts toward or away from the line perpendicular to the boundary (the normal). For example, light slows and bends toward the normal when going from air into water, and it speeds up and bends away from the normal when moving from water back into air. This bending due to a speed change is what we call refraction. Bouncing off a boundary is reflection, not refraction. The idea that refraction stops at the boundary isn’t right—refraction describes the bending that happens as the wave continues into the new medium. Refraction also isn’t limited to sound; it occurs with many wave types, including light and water waves.

Refraction happens because a wave changes speed when it enters a different medium, and that change in speed makes the wave bend as it crosses the boundary. When light (or any wave) moves from one material to another, the part of the wave that enters the new medium changes speed, so its path tilts toward or away from the line perpendicular to the boundary (the normal). For example, light slows and bends toward the normal when going from air into water, and it speeds up and bends away from the normal when moving from water back into air. This bending due to a speed change is what we call refraction.

Bouncing off a boundary is reflection, not refraction. The idea that refraction stops at the boundary isn’t right—refraction describes the bending that happens as the wave continues into the new medium. Refraction also isn’t limited to sound; it occurs with many wave types, including light and water waves.