Polarity, Electric. The disposition in a paramagnetic body to be influenced by electric waves and lines of force. The otherwise non-magnetic body or mass becomes magnetic to attract or repulse when influenced by electricity, but ceases to retain the phenomena after the electric influence is removed. A piece of soft iron wire, a nail, or a short rod of iron will become electro-polarized when a current of electricity is sent through a coil of insulated wire so wound that one end will be N the other S. So soon as the circuit is broken the polarity ceases.
Polarization. The depriving of a voltaic cell of its proper electro-motive force. This may be brought about through the solution becoming spent, or in the event of the acid being saturated with zinc, and so failing to act on the metallic zinc.
Counter electro-motive force due to the accumulation of hydrogen on the negative plate.
Polarizing-current. (See [Current, Polarizing].)
Polar Surface. The surface of a magnetic substance through which the magnetic flux passes in or out.
Pole-changer. An automatic, oscillating switch or contact-breaker which reverses the direction of the current.
Pole, Negative. The S pole in a magnet or compass needle.
Pole, Positive. (See [Positive Pole].)
Pole-switch, Single. A switch designed to open or close one lead only.
Poles. The terminals of an open electric circuit at which there necessarily exists a potential difference.