What is the number of cycles per second in alternating current?

• A. Relative motion
• B. Inductance/Inductor
• C. Current
• D. Frequency

Answer: (D)

Frequency is the number of cycles per second in alternating current. It tells you how often the waveform repeats each second, which is why it’s measured in hertz (Hz). A higher frequency means the wave completes more cycles every second. For context, power systems commonly run at 60 Hz in some regions and 50 Hz in others.

Other terms don’t fit because relative motion describes movement rather than how often the waveform repeats. Inductance is a property of a coil that affects how current changes over time, not the rate of repetition. Current is the actual flow of electric charges at a given moment, not the count of cycles occurring each second.