Whereas, the reactive power is the useless power.

The active power is the product of the voltage, current and the cosine of the angle between them.

Whereas, the reactive power is the product of voltage and current and the sine of the angle between them.

The active power is the real power, and it is measured in watts.

## What is active power and reactive power?

To distinguish reactive power from active power, it is measured in units of “volt-amperes reactive”, or var. These units can simplify to Watts, but are left as var to denote that they represent no actual work output. Energy stored in capacitive or inductive elements of the network give rise to reactive power flow.

## What is the reactive power?

Reactive power is the resultant power in watts of an AC circuit when the current waveform is out of phase with the waveform of the voltage, usually by 90 degrees if the load is purely reactive, and is the result of either capacitive or inductive loads.

## How do you calculate reactive power?

Since the voltage of the reactance is equal to the reactance multiplied by the reactive current, reactive power can be calculated by the formula: Another way to calculate reactive power is to calculate the inductive power and capacitive power and subtract the smaller from the larger.