Impedance (Z, in ohms) includes:

Impedance, denoted as Z and measured in ohms, is a comprehensive measure of the opposition that a circuit presents to the flow of alternating current (AC). It encompasses not only resistance but also reactance, which is the measure of how capacitors and inductors resist changes in current due to their energy storage characteristics.

The correct answer is that impedance includes resistance, capacitive reactance, and inductive reactance. This allows for a complete understanding of the behavior of AC circuits, as it acknowledges that both capacitive and inductive elements contribute to the overall opposition to current flow.

Resistance is the straightforward opposition to current, while capacitive reactance and inductive reactance describe how capacitors and inductors respond to the alternating nature of the current. Specifically, capacitive reactance decreases with increasing frequency and stores energy in an electric field, while inductive reactance increases with frequency and stores energy in a magnetic field.

By recognizing that impedance is a combination of these three elements, one can analyze and predict the performance of AC circuits more accurately. Understanding this composition is essential for designing and troubleshooting electronic systems that operate on alternating current.