What is the main function of an inductor in a circuit?

The main function of an inductor in a circuit is to store electrical energy in a magnetic field. When current flows through an inductor, it creates a magnetic field around it. This process can be understood through the principles of electromagnetism, where the magnetic field is generated due to the movement of electric current.

The stored energy in this magnetic field can later be released back into the circuit when the current changes, which makes inductors particularly useful in applications such as filters, energy storage in power supplies, and in oscillators. Inductors resist changes in current due to this energy storage capability; when the current flowing through the inductor is suddenly altered, the magnetic field takes time to collapse or grow, which leads to the characteristic behavior of inductors in AC circuits and their role in smoothing current waveforms.

The other options reflect different characteristics that might be seen in other components: while inductors do resist changes in current, they do not block DC current nor do they store energy as electric fields. Additionally, limiting current flow is more characteristic of resistors rather than inductors.