What occurs to an inductor's magnetic field when the current flowing through it changes?

When the current flowing through an inductor changes, the magnetic field around the inductor responds to that change. Inductors work on the principle of electromagnetic induction, which states that a changing magnetic field will induce a voltage in the circuit.

When the current increases, the magnetic field expands, and when the current decreases, the magnetic field collapses. This change in magnetic field strength induces a voltage that opposes the change in current according to Lenz's Law. This induced voltage is crucial in managing currents and voltages in electrical circuits, especially in applications like power supplies, filters, and transformers.

Therefore, the dynamic behavior of the magnetic field—collapsing or expanding in response to changes in current—is fundamental to how inductors operate in circuits. This interaction is key to the functioning of many electrical and electronic systems.