How can Reactive Power in a single phase AC circuit be defined?

Reactive power in a single phase AC circuit can be defined as the power that is associated with the energy storage elements, such as inductors and capacitors, which cause the current to be out of phase with the voltage. In AC circuits, when the current and voltage are not perfectly in phase, a portion of the power is not used for useful work (like powering devices) but instead oscillates back and forth between the source and the reactive components in the circuit. This is what is termed as reactive power.

The out-of-phase nature of this current indicates that it does not contribute to the actual work output but rather to maintaining the electric and magnetic fields in the reactive components. Therefore, it is important to understand that while reactive power is crucial for the functioning of AC circuits involving inductors and capacitors, it does not result in consumption of power in the traditional sense like resistive power does. This reasoning supports the characterization of reactive power related to the portion of the line current that is out of phase with the supply voltage.