In electrical circuits, what does impedance refer to?

Impedance refers to the total opposition that a circuit presents to alternating current (AC). It is a crucial concept in electrical engineering, particularly when working with AC circuits. Impedance is not just about resistance; it includes both resistance (the opposition to current flow) and reactance (the opposition to changes in current or voltage due to capacitors and inductors). In a circuit, when an AC voltage is applied, impedance determines how much current will flow, and it can vary with the frequency of the AC signal.

Understanding impedance is essential for analyzing circuit behavior, especially in applications like audio electronics, radio frequency circuits, and power systems. This total opposition acts as a crucial factor in determining the efficiency and performance of the electrical equipment involved.