What does the term 'impedance' refer to in AC circuits?

The term 'impedance' in AC circuits refers to the total opposition to electric current. It encompasses not only the resistance (the opposition to current flow) but also reactance, which is the opposition to current caused by capacitance and inductance in the circuit. In alternating current (AC) systems, impedance is crucial as it determines how much current will flow for a given voltage, affecting the overall performance of the circuit.

Impedance is measured in ohms, just like resistance, but it takes into account both the resistive and reactive components. Therefore, it provides a more comprehensive view of how the circuit will behave under AC conditions compared to resistance alone. Understanding impedance is essential for designing and analyzing AC circuits, as it affects the phase relationship between voltage and current in the circuit.