The time between two successive crests is called what?

• A. Period
• B. Wavelength
• C. Velocity
• D. Amplitude

Answer: (A)

The time between two successive crests defines the period of a wave. It is the duration of one complete cycle at a fixed point, measured in seconds. If a crest arrives every two seconds, that interval is the period. The period is the reciprocal of frequency, so T = 1/f, meaning higher frequency waves have shorter periods. The speed of the wave is related to both period and wavelength by v = λ / T (or v = fλ), linking how fast the wave moves with how long each cycle lasts and how far each crest travels between cycles. Wavelength is a spatial distance between crests, not a time interval, velocity is the rate of wave travel, and amplitude is the height of the wave—properties describing different aspects of the wave.