What is meant by the term "electrical impedance"?

The term "electrical impedance" refers to the total opposition that a circuit presents to the flow of alternating current (AC). Impedance takes into account not only the resistance, which is the opposition to direct current (DC), but also the effects of reactance—this includes both capacitive and inductive effects present in AC circuits.

Unlike resistance, which is a measure of how much a component slows down direct current, impedance is a more comprehensive measure that varies with frequency. This characteristic is crucial for understanding how circuits behave under different AC conditions. Impedance is usually expressed in ohms and is represented in complex form, which allows for the calculation of both magnitude and phase relationship between voltage and current in an AC system.

The other options focus on specific aspects of electrical properties but do not capture the full scope of what impedance encompasses. For example, measuring voltage pertains to the electric potential difference and does not reflect the ability of a circuit to resist current flow under AC conditions, nor does it incorporate frequency-related behavior. Similarly, while current is important in circuit design, it is merely a measure of flow and does not represent the circuit's opposition to that flow. Steady-state resistance does not encompass the dynamics of AC circuits, which is why it's