Which term is defined as the number of wavelengths that pass a fixed point each second?

Which term is defined as the number of wavelengths that pass a fixed point each second?

• A. Frequency
• B. Wavelength
• C. Period
• D. Speed

Answer: (A)

Frequency is the rate at which wave crests pass a fixed point each second. It is measured in hertz, with 1 Hz meaning one crest per second. If the waves arrive more quickly, more crests cross the point every second, so the frequency increases. Wavelength, the distance between successive crests, is a spatial measure, not a rate. Period is the time for one complete cycle and is the reciprocal of frequency. Speed describes how fast the wave travels and relates to both frequency and wavelength through v = fλ. So the term that matches the description is frequency.

Frequency is the rate at which wave crests pass a fixed point each second. It is measured in hertz, with 1 Hz meaning one crest per second. If the waves arrive more quickly, more crests cross the point every second, so the frequency increases. Wavelength, the distance between successive crests, is a spatial measure, not a rate. Period is the time for one complete cycle and is the reciprocal of frequency. Speed describes how fast the wave travels and relates to both frequency and wavelength through v = fλ. So the term that matches the description is frequency.