What is the unit of frequency?

The correct answer is Hertz, which is the standard unit of frequency in the International System of Units (SI). Frequency refers to the number of cycles of a periodic event occurring in one second. Therefore, when we say something has a frequency of one hertz, it means one cycle per second. This concept is widely used in various fields, including physics, engineering, and telecommunications, to quantify oscillations, waves, or any repeating events.

Understanding frequency is essential because it allows professionals to analyze and manipulate systems that operate over designated cycles, whether in sound waves, electrical signals, or mechanical movements. Hertz is a key measurement that helps in describing phenomena such as audio frequencies and the alternating current in electrical circuits.

The other units listed—watt, joule, and volt—relate to different physical concepts. Watt measures power, joule measures energy, and volt measures electric potential; none pertain to the concept of frequency.