Which term refers to the number of crests passing a fixed point per second?

• A. Wave Crest
• B. Wave Frequency
• C. Wave Height
• D. Wave Diffraction

Answer: (B)

The rate at which crests pass a fixed point per second is the wave frequency. Frequency measures how many wave crests (or troughs) cross a given location each second, and it’s measured in hertz. If crests arrive quickly, the frequency is high; if they arrive slowly, the frequency is low. This concept is related to the period of the wave, since f = 1/T. Other terms describe different properties: a wave crest is simply the peak of the wave, wave height is the vertical distance between crest and trough (the amplitude), and diffraction refers to the bending of waves around obstacles rather than how often crests pass.