What does impedance refer to in an electrical circuit?

Impedance is a comprehensive concept used in electrical circuits, particularly in the context of alternating current (AC). It refers to the total opposition that a circuit presents to the flow of AC, and it encompasses two main components: resistance and reactance.

Resistance is the opposition to current flow provided by circuit components such as resistors. Reactance, on the other hand, comes from the capacitors and inductors in the circuit, which can store and release energy in the form of magnetic or electric fields, impacting the flow of current in AC circuits.

Impedance is measured in ohms and is usually represented by the symbol Z. This total opposition is crucial in understanding how AC circuits behave, as it dictates how much current will flow for a given voltage. In summary, impedance combines both the resistive and reactive elements of the circuit, making option C the accurate choice in describing what impedance refers to in an electrical circuit.