In electrical engineering, what does "reactance" refer to?

Reactance is a property of electrical circuits that describes the opposition to the flow of alternating current (AC) due to inductance and capacitance. It is not concerned with direct current (DC); thus, it inherently includes the effects of changing currents or voltages over time, which is a characteristic of AC systems. Inductive reactance occurs in coils or inductors when alternating current flows through them, while capacitive reactance occurs in capacitors under the same conditions.

In AC circuits, reactance leads to phase differences between the voltage and current, ultimately impacting the overall impedance of the circuit. This concept is integral to understanding how AC circuits function, especially when dealing with electric power systems, electronics, and various applications which require the analysis of AC signals.

The other concepts mentioned do not accurately reflect the definition of reactance. Total resistance refers to the overall resistance in a circuit, which includes both resistive and reactive components. Resistance to direct current specifically addresses the opposition to DC not considering the dynamic behavior of AC. Power factor correction is related to improving the efficiency of an electrical system by minimizing the phase difference between voltage and current, but it does not define reactance itself.