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(electrical engineering) An electromagnet, consisting of a coil of wire through which a current flows, used to generate a magnetic field in an electromagnetic machine, typically a rotating machine such as a motor or generator.

Modern (c. 2009) low-cost universal motor, from a vacuum cleaner. Field windings are dark copper colored, toward the back, on both sides. The rotor's laminated core is gray metallic, with dark slots for winding the coils. The commutator (partly hidden) has become dark from use; it's toward the front. The large brown molded-plastic piece in the foreground supports the brush guides and brushes (both sides), as well as the front motor bearing.