What does the term "impedance" refer to?

Impedance refers to the total resistance that a circuit presents to alternating current (AC). It incorporates not only the resistance in ohms that opposes current flow but also the effects of inductance and capacitance, which can vary with frequency. This means that impedance is a more comprehensive measure than resistance alone, as it accounts for how the circuit reacts to changes in AC signals.

In an AC circuit, impedance is key to understanding how voltage and current behave, as it affects the phase relationship between the two. When analyzing AC circuits, engineers use impedance to determine how much current will flow for a given voltage and how the circuit's components will interact over varying frequencies. Overall, the concept of impedance is critical to ensuring that circuits operate efficiently and effectively within their designed specifications.