Define "frequency" in the context of electrical signals.

Frequency in the context of electrical signals refers specifically to the number of cycles per second of a periodic wave. It is measured in hertz (Hz), where one hertz equals one cycle per second. This concept is fundamental in understanding how alternating current (AC) signals behave, particularly in power systems and communication technologies.

In practical terms, frequency indicates how often a waveform repeats itself over time. For example, in power systems, the standard frequency of electricity in many countries is 60 Hz, meaning the current changes direction 60 times every second. This characteristic affects the design and function of electrical equipment, including motors and generators, which are designed to operate efficiently at specific frequencies.

Understanding frequency is crucial for those involved in electrical and instrumentation fields, as it influences everything from signal transmission to the operation of devices. The other options refer to different electrical concepts: electrical current measures flow, time period refers to the duration of one cycle, and voltage pertains to the electric potential in a circuit. Each of these has its own significance but does not specifically define the concept of frequency.