How is frequency measured?

• A. In radians per second
• B. In cycles per minute
• C. In meters per second
• D. In hertz, representing the number of cycles per second

Answer: (D)

Frequency is the rate at which repetitions occur over time. In the context of waves and signals, it’s how many cycles happen each second, and the standard unit for this is hertz, representing the number of cycles per second. So when we say frequency in hertz, we’re directly measuring how often the cycle repeats every second.

Radians per second, while related, describes angular velocity (how quickly the phase angle changes) rather than the count of whole cycles per second. Meters per second measures speed, not repetition rate. Cycles per minute could describe the rate in another time unit, but it’s not the standard SI unit; you’d convert to hertz by dividing by 60.