Opposition to the flow of alternating current in an AC circuit is called what?

• A. Capacitance
• B. Inductance
• C. Resistance
• D. Impedance

Answer: (D)

In AC circuits, the total opposition to current flow is called impedance. This term captures everything that resists the flow of alternating current, including the plain resistance of conductors and the reactive effects from capacitors and inductors. Unlike DC, where opposition is just resistance, AC brings phase differences between voltage and current because reactive elements store and release energy. Impedance, represented by Z, combines these resistive and reactive parts into a single quantity with both magnitude (how much it resists) and phase (how much the current lags or leads). Capacitance relates to storing charge, not the overall opposition. Inductance relates to opposing changes in current, contributing to reactance but not describing the whole opposition by itself. Resistance is the basic opposition to current, but in AC the full picture is impedance.