Final answer:
An electromagnet is a device that employs electric current to create a magnetic field with a ferromagnetic core to produce powerful magnetic effects. The alignment of atomic domains in the core amplifies this field, enabling electromagnets to be used in a variety of applications.
Step-by-step explanation:
An electromagnet is a device with a ferromagnetic core. This ferromagnetic core can produce very strong magnetic effects when current is passed through the wire windings surrounding the core. Electromagnets operate on the principle that an electric current through a wire generates a magnetic field; the alignment of domains within the ferromagnetic material in the core amplifies this magnetic field. The poles of an electromagnet are aligned with the direction of the electric current, establishing its north and south poles.
Domains are regions within a magnetic material where the magnetic poles of individual atoms are aligned. When an electromagnet is activated, these domains align themselves in the direction of the magnetic field produced by the wire windings, resulting in a stronger magnetic field. Common applications for electromagnets include electric motors, where electrical energy is transformed into mechanical energy, and various industrial uses, such as in cranes for lifting heavy metallic objects.