A part, in an electrical switching device, made of conducting
material, for the purpose of closing, opening, or changing the conductive
path of an electrical circuit. To open or close a circuit, an electric
contact is made to come in contact with or separate from its mating part.
Devices embodying contacts for these purposes are electric switches,
relays, contactors, and circuit breakers. Contacts may be actuated directly
or through a linkage that is driven either manually, mechanically, electromagnetically,
hydraulically, or pneumatically. An electric contact is also an essential
part of a variable resistor.
In such an application the contact or wiper provides a moving connection
to the resistive element.