electric arcA high-current electric discharge between two electrodes. The current is carried by the gas plasma maintained by the discharge. Sodium and neon lights exemplify large relatively cool arcs, while arc-welding uses a small very hot arc between a slowly consumed electrode and the workpiece. Lightning is a naturally occurring arc. See also arc lamp. Related categories• ELECTRICITY AND MAGNETISM• TECHNOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |