... silver. Copper and alu-minum are also excellent electrical conductors. Iron, steel, and various other metals arefair to good conductors of electricity. In most electrical circuits and systems, ... have a motor thatchanges electricity into useful mechanical energy.A magnetic field contains energy of a unique kind. The science of magnetism isclosely related to electricity. Magnetic phenomena ... field, and a fluctuatingelectric field produces a changing magnetic field. This phenomenon, called electro- magnetism, makes it possible to send radio signals over long distances. The electricand...