Alternating Current. (See [Current, Alternating].)
Alternating Current-power. Electrical distribution employing the alternating current from dynamos or converters.
Alternation. A change in the direction of a current; to and fro. Alternations may take place with a frequency ranging from 500 to 10,000 or more vibrations per second.
Alternator. An electric generator-dynamo supplying an alternating current.
Amalgam. A combination of mercury with any other metal.
Amalgamation. The application of mercury to a metal, the surface of which has been cleansed with acid. Mercury will adhere to all metals, except iron and steel, and particularly to zinc, which is treated with mercury to retard the corrosive action of acid on its surface.
Amber. A fossil resin, valuable only in frictional electric experiments. Most of it is gathered on the shores of the Baltic Sea between Königsberg and Memel. It is also found in small quantities at Gay Head, Massachusetts, and in the New Jersey green sand. When rubbed with a cloth it becomes excited with negative electricity.
Ammeter. The commercial name for an ampere-meter. An instrument designed to show, by direct reading, the number of amperes of current which are passing through a circuit.
Ampere. The practical unit of electric current strength. It is the measure of the current produced by an electro-motive force of one volt through a resistance of one ohm.
Ampere-currents. The currents theoretically assumed to be the cause of magnetism.