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A mass, usually of soft iron, but sometimes of some other magnetic metal, as nickel or cobalt, rendered temporarily magnetic by being placed within a coil of wire through which a current of electricity is passing. The metal is generally in the form of a bar, either straight, or bent into the shape of a horseshoe.…

g to, or produced by, magnetism which is developed by the passage of an electric current. Electro-magnetic engine, an engine in which the motive force is electro-magnetism. -- Electro-magnetic theory of light (Physics), a theory of light which makes it consist in the rapid alternation of transient electric currents mo…

The magnetism developed by a current of electricity; the science which treats of the development of magnetism by means of voltaic electricity, and of the properties or actions of the currents evolved.

1893 and by U. S. Statute as, one tenth of the unit of current of the C. G. S. system of electro-magnetic units, or the practical equivalent of the unvarying current which, when passed through a standard solution of nitrate of silver in water, deposits silver at the rate of 0.001118 grams per second. Called also the i…

A piece of soft iron used to connect the two poles of a magnet, or electro-magnet, in order to complete the circuit, or to receive and apply the magnetic force. In the ordinary horseshoe magnet, it serves to prevent the dissipation of the magnetic force.

record of the time at which any observed phenomenon occurs, or of its duration. It has an electro-magnetic register connected with a clock. See Chronograph.

s or machine for producing motion and mechanical effects by the action of electricity; an electro-magnetic engine.

ctricity excites another current in a neighboring conductor forming a closed circuit. -- Electro-magnetic induction, the influence by which an electric current produces magnetic polarity in certain bodies near or around which it passes. -- Electro-static induction, the action by which a body possessing a charge of st…

o-electric machine in which the field is maintained by permanent steel magnets instead of electro-magnets.

ng a great quantity of electricity of low tension, and hence adapted to the exhibition of electro-magnetic phenomena. [R.]

it is a resistance substantially equal to 109 units of resistance of the C.G.S. system of electro-magnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice 14.4521 grams in mass, of a constant cross-sectional area, and of the l…

or dull metal with a thin plate of precious or bright metal, as by mechanical means or by electro-magnetic deposition.