What is diffraction?

What is diffraction?

• A. Sound waves bending around obstacles.
• B. Sound waves reflecting off surfaces.
• C. Sound waves changing speed when entering a different medium.
• D. Sound waves increasing in frequency.

Answer: (A)

Diffraction is the bending and spreading of waves as they meet an obstacle or pass through a gap. For sound, this means the waves bend around edges and spread into the space beyond barriers, so you can hear sounds even when you aren’t in a direct line with the source. This is why you can hear someone around a corner or through a doorway. It’s different from reflection, where waves bounce off surfaces; and from refraction, where waves change speed and bend when moving into a different medium. It isn’t about a change in frequency, which relates to pitch changes due to motion rather than bending around obstacles. So describing sound waves bending around obstacles best captures diffraction.

Diffraction is the bending and spreading of waves as they meet an obstacle or pass through a gap. For sound, this means the waves bend around edges and spread into the space beyond barriers, so you can hear sounds even when you aren’t in a direct line with the source. This is why you can hear someone around a corner or through a doorway. It’s different from reflection, where waves bounce off surfaces; and from refraction, where waves change speed and bend when moving into a different medium. It isn’t about a change in frequency, which relates to pitch changes due to motion rather than bending around obstacles. So describing sound waves bending around obstacles best captures diffraction.