Why do inductors behave like resistors in alternating current?

Inductors behave like resistors in alternating current (AC) due to the property of inductive reactance. Inductive reactance is the opposition that an inductor presents to the change in current, which increases with the frequency of the AC signal. This reactance causes the inductor to limit the current flow similarly to how a resistor would, although the mechanism is different. While a resistor dissipates energy as heat, an inductor temporarily stores energy in a magnetic field and releases it, causing a phase shift between the voltage and current.

In AC, inductors behave like resistors because they resist changes in current. This resistance, called inductive reactance, is proportional to the frequency of the AC signal and the inductance of the inductor. As the AC frequency increases, the inductive reactance increases, reducing the current flow through the inductor, similar to how a resistor would limit current. However, this is due to the magnetic field interaction rather than direct energy dissipation.

In AC, an inductor behaves as an element that opposes changes in current due to its inductive reactance. This results in a phase shift where the current lags behind the voltage by 90 degrees in an ideal inductor. The inductor provides impedance to the AC signal, which is frequency-dependent and increases with higher frequencies. This impedance restricts the current flow and affects the circuit’s overall behavior, similar to resistance but through a different mechanism.

An inductor has resistance because it is made of conductive wire, typically copper, which inherently has some electrical resistance. This resistance is separate from the inductive reactance and causes power loss in the form of heat, similar to a resistor. The total opposition an inductor presents in an AC circuit is a combination of this ohmic resistance and the inductive reactance.

An inductor is not exactly like a resistor, but it shares some similarities in how it affects AC circuits. Both components limit current, but they do so through different mechanisms. A resistor dissipates electrical energy as heat, providing a consistent opposition to current regardless of frequency. An inductor, on the other hand, stores energy in a magnetic field and releases it, providing frequency-dependent opposition to current (inductive reactance). While they can have similar effects in AC circuits, their underlying principles and behaviors differ significantly.