Which term describes the bending of waves as they pass from air into water due to a change in speed?

Which term describes the bending of waves as they pass from air into water due to a change in speed?

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

Answer: (A)

Refraction is the bending of a wave as it passes from one medium to another with a different propagation speed. When light moves from air into water, its speed decreases in the denser medium, so the wavefront changes direction and the ray bends toward the normal. This change in direction occurs because different parts of the wavefront enter the second medium at different speeds, causing the overall path to tilt. The amount of bending follows Snell’s law, relating the incident and refracted angles to the speeds (or indices) of the two media. If the wave were moving from water back into air, where it speeds up, it would bend away from the normal. The other terms describe different phenomena: reflection is bouncing off the boundary, diffraction is bending around edges or through openings, and absorption is energy loss in the medium.

Refraction is the bending of a wave as it passes from one medium to another with a different propagation speed. When light moves from air into water, its speed decreases in the denser medium, so the wavefront changes direction and the ray bends toward the normal. This change in direction occurs because different parts of the wavefront enter the second medium at different speeds, causing the overall path to tilt. The amount of bending follows Snell’s law, relating the incident and refracted angles to the speeds (or indices) of the two media. If the wave were moving from water back into air, where it speeds up, it would bend away from the normal. The other terms describe different phenomena: reflection is bouncing off the boundary, diffraction is bending around edges or through openings, and absorption is energy loss in the medium.