How is impedance measured?

Impedance is measured in ohms, which is a unit that quantifies the opposition that a circuit presents to the flow of alternating current (AC). In an AC circuit, impedance is a combination of resistance and reactance, the latter arising from inductors and capacitors. Resistance is the measure of opposition to current flow in a purely resistive component, while reactance accounts for the effects of inductance and capacitance in the circuit.

When analyzing circuits, especially complex ones where both resistive and reactive components are present, understanding impedance is crucial because it influences how current flows and how voltage drops across components are realized. Working with ohms provides clarity on the interaction between voltage, current, and the overall behavior of the electrical system.

The other options pertain to different electrical quantities: volts measure voltage, amperes measure current, and henrys measure inductance, but none of them are appropriate units for impedance.