Which component is defined as a coil of wire that stores energy in a magnetic field?

The component that is defined as a coil of wire that stores energy in a magnetic field is an inductor. When an electric current flows through the coil, it generates a magnetic field around it. This property is due to the fundamental behavior of inductors, where they oppose changes in current flow. When the current increases, the inductor stores energy in the magnetic field, and when the current decreases, the inductor releases that energy back into the circuit. This capability of inductors is widely utilized in various applications, including tuning circuits, filters, and energy storage systems.

Inductors are characterized by their inductance, which is measured in henries (H), and they play a vital role in managing the flow of electricity in AC circuits, acting as a form of energy storage and helping to smooth out electrical signals.

Other components listed have different roles: capacitors store energy in an electric field, resistors limit current flow without storing energy, and transformers transfer electrical energy between different voltage levels using electromagnetic induction but are not defined primarily as a device that stores energy.