What is impedance?

Impedance, commonly represented by the letter 'Z', is defined as the total opposition to the flow of alternating current (AC) in a circuit. It is measured in ohms, just like resistance. While resistance opposes both direct current (DC) and alternating current equally, impedance is a broader term. It combines simple DC resistance with reactance, which is the specific opposition to AC caused by capacitors and inductors. Other options are incorrect definitions of standard electrical terms. For example, the inverse of resistance is conductance, not impedance. Power handling capability relates to component ratings (like wattage), not the opposition to current.