Electrode

Electrode, component of an electric circuit that connects the conventional wiring of the circuit to a conducting medium such as an electrolyte or a gas. The electrically positive electrode is called the anode and the negative electrode the cathode. The ordinary dry cell battery employs a carbon anode and a zinc cathode in contact with an electrolytic solution. Arc-lamp electrodes are made of carbon, and the electrodes used in arc welding are made of flux-coated metal. The electrodes of vacuum tubes are fabricated from carbon and various metals and alloys, depending on the purpose for which the tubes are used.