In an AC circuit, impedance represents the total opposition to current, including resistance and reactance.

In an AC circuit, impedance represents the total opposition to current, including resistance and reactance.

• A. Only the resistive portion
• B. The phase angle between voltage and current
• C. The total opposition to current, including resistance and reactance
• D. The reactance

Answer: (C)

In AC circuits, impedance represents the total opposition to current, combining both resistance and reactance so you capture how much current is blocked and how the voltage and current are aligned in time. Impedance is a complex quantity Z, often written as Z = R + jX, where R is the resistive part that dissipates real power as heat and X is the reactance that stores and releases energy in the magnetic or electric fields. The overall opposition the current sees has a magnitude |Z| = sqrt(R^2 + X^2); this tells you how much the current is reduced in amplitude. The phase relationship between voltage and current is given by the angle φ = arctan(X/R); this shows whether the current lags or leads the voltage due to the reactive part. So the statement that correctly describes impedance is that it is the total opposition to current, including both resistance and reactance. The resistive portion alone omits the reactive effects, and the reactance alone omits the dissipative resistance. The phase angle is about the timing difference, not the total opposition itself.

In AC circuits, impedance represents the total opposition to current, combining both resistance and reactance so you capture how much current is blocked and how the voltage and current are aligned in time. Impedance is a complex quantity Z, often written as Z = R + jX, where R is the resistive part that dissipates real power as heat and X is the reactance that stores and releases energy in the magnetic or electric fields. The overall opposition the current sees has a magnitude |Z| = sqrt(R^2 + X^2); this tells you how much the current is reduced in amplitude. The phase relationship between voltage and current is given by the angle φ = arctan(X/R); this shows whether the current lags or leads the voltage due to the reactive part.

So the statement that correctly describes impedance is that it is the total opposition to current, including both resistance and reactance. The resistive portion alone omits the reactive effects, and the reactance alone omits the dissipative resistance. The phase angle is about the timing difference, not the total opposition itself.