Reactance

Reactance is the invented part of electrical impedance, a measure of opposition to a sinusoidal alternating current. Reactance arises from the occurrence of inductance and capacitance within a circuit, and the SI unit is the ohm. The value of the reactance is a lower maximum value on the amount of the impedance. A positive reactance implies that the phase of the voltage leads the phase of the current, while a harmful reactance implies that the phase of the voltage lags the phase of the current. A reactance of zero implies the current and voltage are in phase and equally if the reactance is non-zero then there is a phase distinction between the voltage and current