What describes the number of times per second that an alternating current makes a complete cycle?

The term that describes the number of times per second that an alternating current (AC) makes a complete cycle is frequency. Frequency is a fundamental characteristic of alternating current and is measured in hertz (Hz), where one hertz is equal to one cycle per second.

In the context of electricity, frequency indicates how often the current reverses direction within a second. For instance, in the US, the standard frequency for AC power is typically 60 Hz, meaning the current makes 60 complete cycles every second. This concept is crucial for ensuring that electrical devices operate correctly and synchronize with the power supply.

Other terms such as pulse rate or speed do not accurately describe this phenomenon in the context of AC. Wavelength refers to the distance between successive peaks of a wave and is typically used in the context of radio frequencies rather than describing the cycles per second. Thus, frequency is the correct and precise term for this electric characteristic.