Which phenomenon describes the reinforcement of waves when they arrive in phase?

Which phenomenon describes the reinforcement of waves when they arrive in phase?

• A. Scattering
• B. Diffraction
• C. Interference
• D. Absorption

Answer: (C)

Constructive interference is the phenomenon where waves reinforce each other when they arrive in phase. When two waves share the same frequency and their crests align with crests while troughs align with troughs, their displacements add up, producing a larger amplitude. This is why light can appear brighter in regions where waves meet in phase and why sound can seem louder where the waves reinforce each other. The underlying idea is the superposition of waves: where the phase matches, amplitudes add; where it is mismatched, they can partially or fully cancel (destructive interference). Scattering, diffraction, and absorption describe different effects that don’t specifically capture the reinforcement due to phase alignment.

Constructive interference is the phenomenon where waves reinforce each other when they arrive in phase. When two waves share the same frequency and their crests align with crests while troughs align with troughs, their displacements add up, producing a larger amplitude. This is why light can appear brighter in regions where waves meet in phase and why sound can seem louder where the waves reinforce each other. The underlying idea is the superposition of waves: where the phase matches, amplitudes add; where it is mismatched, they can partially or fully cancel (destructive interference). Scattering, diffraction, and absorption describe different effects that don’t specifically capture the reinforcement due to phase alignment.