Definition
The unit used to measure reactive power in an alternating current (AC) circuit. Reactive power is the portion of electrical power that flows back and forth between the source and inductive or capacitive components (such as motor windings or transformers) without doing useful work. It is calculated by multiplying voltage by the current that is out of phase with that voltage.
Plain English
A measurement of the electrical power in an AC circuit that gets pushed back and forth without actually powering anything. It supports the magnetic fields that motors and transformers need to operate, but it isn't the power that does the real work.
Context Anchor
Seen in aircraft electrical power discussions, especially when checking AC generator load and equipment that uses coils or motors.
Derivation
The name comes directly from the math: volts multiplied by amps gives a power value, and 'reactive' refers to circuit components (inductors and capacitors) that react to changing current by storing and releasing energy rather than consuming it. Calling it volt-amps reactive — instead of watts — signals that this isn't real working power.
Why Pilots Care
Aircraft generators must be rated to supply both real power and volt-amps reactive; excessive reactive load reduces efficiency and can overheat windings.
Grounding Statement
Think of reactive power as the energy sloshing back and forth in a motor's coils to keep its magnetic field alive — necessary for the motor to run, but not the energy that actually turns the shaft.
Intuition Check
Reactive does not mean “quick to respond” here. It means the electrical load stores energy briefly and sends it back, so some current flows without becoming useful work.
Example Sentence 1
The flight engineer adjusted the generator controls to balance the VAR load between the two AC generators.
Example Sentence 2
Technicians recorded volt-amps reactive readings to verify the power factor stayed within limits after the generator overhaul.