Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The concept of electrical impedance is best defined as the total opposition to alternating current (AC) in a circuit. Impedance encompasses not only the resistance, which is the opposition to direct current (DC), but also includes the effects of inductance and capacitance that can influence AC circuits.

In more detail, while resistance is a measure of how much a component opposes the flow of current, impedance factors in how those components react to changes in voltage and current over time, which is particularly important in AC systems. The presence of inductors and capacitors introduces additional phase relationships between voltage and current, leading to a more complex interaction than simple resistance. Therefore, stating that impedance is the total opposition to AC current accurately captures the complete characteristics of an AC circuit, integrating both resistance and reactance.

Other options do not reflect the comprehensive nature of impedance. While resistance is part of impedance, saying that impedance is equal to resistance only overlooks the contributions made by inductors and capacitors in AC circuits. Also, asserting that impedance does not affect DC circuits simplifies the concept; impedance is not typically relevant in a DC context since it is predominantly associated with AC. Lastly, claiming that impedance is solely due to resistance ignores the reactive components that are crucial in determining the