Which term describes the vertical distance between the crest and trough of a wave?

• A. Wave Diffraction
• B. Wave Period
• C. Wave Refraction
• D. Wave Height

Answer: (D)

The vertical distance between the crest and the trough is called wave height. This measures how tall the wave is—from the lowest point to the highest point. It’s related to amplitude, since height equals twice the amplitude (amplitude is the displacement from mean water level to the crest). The energy a wave carries increases with the square of its height, so taller waves pack more energy. This term is distinct from the time-based wave period, which is the interval between crests, and from diffraction and refraction, which describe how waves bend or change direction rather than their vertical size.