The bending of a wave around an obstacle is known as what?

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

Answer: (B)

Waves bend around obstacles through a process called diffraction. This happens because every point on a moving wavefront acts as a new source of secondary waves. When these wavelets meet the edge of an obstacle or pass through a small opening, they spread into the region behind it and interfere with each other, producing a bent or spread-out wave pattern.

This is different from refraction, which is the bending that occurs when a wave crosses into a medium where its speed is different; reflection is the bouncing back of waves from a surface; and deflection isn’t the standard term used to describe how waves interact with obstacles. Diffraction explains why light can bend around a corner and why sound can be heard around a doorway or through a slit.