Meaning – The term frequency, is defined as the rate of signal oscillation. Generally speaking, frequency is defined as the number of times that an event occurs, in a given time period.
In the case of electrical current, frequency is the number of times a sine wave repeats or completes, a positive-to-negative cycle. The more cycles that occur per second, the higher the frequency.
The frequency is measured in hertz, denoted by the symbol Hz.
Circuits and equipment are often designed to operate at a fixed or variable frequency. Equipment designed to operate at a fixed frequency performs abnormally if operated at a different frequency than specified.
The equipment used to measure the frequency is a digital multimeter.
Example of usage – “If an alternating current is said to have a frequency of 7 Hz (see diagram below), that indicates its waveform repeats 7 times in 1 second.”