What does an inductor oppose according to its function?

An inductor operates based on the principle of electromagnetic induction, specifically opposing changes in current flow through it. When a current passes through an inductor, it creates a magnetic field around it. If there is a change in current—either an increase or a decrease—the inductor generates a counter electromotive force (EMF) in the opposite direction of the change. This phenomenon is what allows the inductor to oppose the change in current.

Understanding the function of an inductor is crucial for managing electrical systems effectively, as it helps in smoothing out variations in current and in stabilizing power supplies in circuits. This property is especially relevant in applications such as filtering, energy storage in power supplies, and in oscillators.

The other options are related to different aspects of electrical theory. Voltage is the potential difference that drives current flow, resistance refers to the opposition to current flow, and capacitance involves the ability to store electrical energy in an electric field. However, these concepts do not describe the specific role of an inductor in opposing changes in current directly.