What is the symbol used to represent impedance in electrical equations?

The correct symbol used to represent impedance in electrical equations is Z. Impedance is a measure of opposition that a circuit offers to the flow of alternating current (AC) due to both resistance and reactance. It is a complex quantity that is expressed in ohms, and is crucial in the analysis of AC circuits, including analyzing the phase relationships between current and voltage.

Resistance is represented by R, which refers specifically to the opposition to current flow in a purely resistive circuit. Voltage is represented by V, denoting the electrical potential difference between two points. Current is represented by I, which measures the flow of electric charge. While these other terms are important in electrical theory, they pertain to different aspects of electrical circuits rather than the overall opposition to AC current, which is what impedance encapsulates.