An opposition to current flow that occurs in alternating current circuits is called?

Impedance is the correct term for opposition to current flow in alternating current (AC) circuits. It encompasses not only resistance, which opposes current flow in both AC and direct current (DC) circuits, but also incorporates the effects of inductance and capacitance that are unique to AC circuits.

In an AC circuit, impedance represents the total opposition to current flow and is a complex quantity measured in ohms. It takes into account both the resistive component, which dissipates energy, and the reactive components (inductance and capacitance), which store and release energy. This means that the behavior of AC circuits can be significantly different from that of DC circuits, making impedance a crucial concept in AC analysis.

Resistance alone does not fully describe the behavior of AC circuits because it does not factor in the effects of inductors and capacitors. Voltage is not a measure of opposition but rather the driving force that pushes current through a circuit. Inductance is specifically related to the property of an inductor to oppose changes in current, but it does not encompass the complete opposition encountered in an AC circuit.

This comprehensive understanding of opposition in AC circuits highlights why impedance is the appropriate term in this context.