What is a coil of wire with an iron core called?

A coil of wire with an iron core is referred to as an electromagnet. This designation arises because the coil creates a magnetic field when an electric current flows through it. The iron core significantly enhances this magnetic field, making it much stronger than it would be if only the wire were present.

Electromagnetism is based on the principle that an electric current produces a magnetic field, and the inclusion of a ferromagnetic material like iron intensifies that field. This is why electromagnets are commonly used in applications such as motors, generators, magnetic locks, and various types of sensors. The ability to turn the electromagnet on and off with electricity is a key feature that distinguishes it from permanent magnets, providing utility in electric circuits and machinery.

Other options highlight different concepts. A magnetron, for example, is a type of vacuum tube that generates microwaves, whereas a transformator (often called a transformer) is used to convert electrical energy from one voltage level to another but does not typically have an iron core in the same configuration. An inductor, on the other hand, is a passive electrical component that stores energy in a magnetic field, but it is usually not defined specifically as having an iron core. Thus, the definition of an