What unit measures "apparent" power?

Apparent power is a crucial concept in electrical engineering, representing the total power in an AC circuit, both used and unused. It is measured in kilovolt-amperes (kVA), which captures the combination of both active power (measured in kilowatts, or kW) and reactive power (measured in kilovolt-amps reactive, or kVAR).

The unit of kilovolt-amperes is specifically designed to represent this "apparent" power, which does not indicate how much power is actually converted into useful work (like that done by kilowatts) but rather includes all the power flowing in the circuit. This distinction is essential for understanding and managing electrical systems, particularly when dealing with inductive or capacitive loads.

In contrast, kilowatts measure the active power that performs work in the circuit, kilovolt-amp-reactance relates to the reactive component of power, and watts measure power in more straightforward DC circuits. Thus, the choice of kilovolt-amperes as the unit for apparent power effectively encompasses the totality of power within AC systems, making it the correct answer.