electrical energy. Energy possessed by a material or device because of an unequal distribution of electrons. Chemical energy, mechanical energy, heat energy, and light energy can all be converted into electrical energy.
electrical generator. A machine that converts mechanical energy into electrical energy. Mechanical energy is used to move conductors through a magnetic field, and voltage is induced into them as they cut across the lines of magnetic flux.
electrical insulator. A material that offers a large amount of opposition to the flow of electrons. Glass, most types of plastic, ceramics, and a vacuum are examples of electrical insulators.
electrically suspended gyroscope. A gyroscope whose rotor is supported in either an electrostatic or electromagnetic field, rather than in conventional bearings. The gyroscope spins with an absolute minimum of friction while it is supported in either of these fields.
electrical potential. The electrical force caused by a deficiency of electrons in one location and an excess of electrons in another. Electrical potential is measured in volts.
electrical resistance welding. A method of welding thin sheets of metal by clamping them tightly together and passing electric current through them. The heat produced by the current melts the metal, and the pressure forces the molten metal from the two sheets together. Spot welding and seam welding are both types of electrical resistance welding.

electrical shield. A housing made of a conductive material such as copper or aluminum that encloses an electrical circuit. The shield picks up stray electrical energy radiated from the circuit and carries it to ground so it cannot interfere with any other electrical or electronic equipment.