What does reactive power represent in an AC circuit?

Reactive power in an AC circuit represents power that oscillates back and forth between the source and reactive components, such as inductors and capacitors, but does not perform any useful work. It is a critical concept in the management of AC power systems because while it is necessary for maintaining the voltage levels that enable the system to function, it does not contribute to the overall energy consumed by resistive loads that perform work.

In an AC circuit, resistive loads consume active power, which does work and is measured in watts. In contrast, reactive power, measured in reactive volt-amperes (VARs), is associated with the phase difference between voltage and current and reflects the energy that is temporarily stored in these reactive components. Therefore, the correct interpretation is that reactive power is the component of electrical power that oscillates and does not result in a net transfer of energy to the load over a complete cycle, hence, it is characterized as not doing useful work.