Which statement best describes the relationship between frequency and cycles per second?

• A. Frequency equals the number of cycles per second.
• B. Frequency equals the number of cycles per meter.
• C. Frequency equals the number of cycles per millisecond.
• D. Frequency equals the speed of sound.

Answer: (A)

Frequency is the rate at which cycles occur over time. For a wave, it tells you how many complete cycles pass a fixed point each second, so it is naturally described as cycles per second (the unit is hertz). The idea of cycles per meter describes spatial repetition, not how often cycles occur in time, so it doesn’t capture the temporal rate. While you could measure frequency in cycles per millisecond, the standard definition uses per second. The speed of sound is a velocity, not a count of cycles, and while frequency and speed relate through wavelength, they are different quantities. So describing frequency as cycles per second matches the way we measure how often cycles happen in time.