Which term describes the alignment of peaks and troughs in a sound wave?

• A. Amplitude
• B. Wavelength
• C. Phase
• D. Frequency

Answer: (C)

Phase describes how the peaks and troughs of a wave line up in time. It captures the relative position of points in the wave cycle: if two waves reach their peaks and troughs at the same moments, they’re in phase; if one wave’s peak occurs as the other’s trough, they’re out of phase. Amplitude is about how tall the wave is (loudness), frequency is how many cycles occur per second (pitch), and wavelength is the spatial distance between repeats. So the term that describes the alignment of peaks and troughs is phase.