What is the definition of reactive power?

Reactive power is defined as the power that oscillates between the source and the load in an alternating current (AC) system. This phenomenon occurs due to the presence of inductive and capacitive elements within the circuit, which cause the current to lag or lead the voltage waveform, respectively. Unlike active power, which performs useful work such as lighting a bulb or turning a motor, reactive power does not result in a net transfer of energy to the load.

In AC circuits, reactive power is crucial for maintaining the voltage levels necessary for the system’s operation, even though it does not perform any actual work. It enables the necessary magnetic fields in inductive devices like transformers and motors to function properly. Therefore, understanding reactive power is essential for ensuring the reliability and efficiency of electrical systems.

This understanding clarifies the functionality of reactive power within the network, validating the choice that identifies it as power that oscillates between the source and the load. The other definitions provided do not encapsulate the unique characteristics and behavior of reactive power in an AC system.