In an AC circuit containing resistance and reactive components, what is the term used for the opposition to current flow?

In an AC circuit that includes both resistance and reactive components, the term used for the opposition to current flow is impedance. Impedance is a complex quantity that encompasses both resistance (the opposition to direct current flow) and reactance (the opposition due to capacitive and inductive components). This means that impedance considers not just how much the circuit resists current flow due to resistance but also how that flow is affected by the inductors and capacitors present in the circuit, which can store and release energy.

In contrast, while resistance specifically measures how much a material opposes the flow of electric current, it does not account for the phase differences created by inductive and capacitive elements in an AC circuit. Voltage and current, on the other hand, describe the electrical potential and flow of electrons respectively, rather than any form of opposition to that flow. Therefore, impedance is the most comprehensive term applicable in this context, recognizing all the factors that affect current flow in an AC circuit.