Induction, Electrostatic.
An electrostatic charge has always an opposite and bound charge. This
may be so distributed as not to be distinguishable, in which case the
charge is termed, incorrectly but conventionally, a free charge. But
when a charge is produced an opposite and equal one always is formed,
which is the bound charge. The region between the two charges and
permeated by their lines of force, often curving out so as to embrace a
volume of cross-sectional area larger than the mean facing area of the
excited surfaces, is an electrostatic field of force. The establishing
of an electrostatic field, and the production of a bound charge are
electrostatic induction.
An insulated conductor brought into such a field suffers a
redistribution of its electricity, or undergoes electrostatic induction.
The parts nearest respectively, the two loci of the original and the
bound charges, are excited oppositely to such charges. The conductor
presents two new bound charges, one referred to the original charge, the
other to the first bound charge.
Induction, Horizontal.
In an iron or steel ship the induction exercised upon the compass needle
by the horizontal members of the structure, such as deck-beams, when
they are polarized by the earth's magnetic induction. This induction
disappears four times in swinging a ship through a circle; deviation due
to it is termed quadrantal deviation. (See Deviation, Quadrantal.)
Induction, Lateral.
A term formerly used to express the phenomenon of the alternative
discharge of a Leyden jar or other oscillatory discharge of electricity.
(See Discharge, Alternative.)
Induction, Magnetic.
The magnetization of iron or other paramagnetic substance by a magnetic
field.
On account of its permeability or multiplying power for lines of force,
a paramagnetic body always concentrates lines of force in itself if
placed in a magnetic field, and hence becomes for the time being a
magnet, or is said to be polarized.
As the tendency of lines of force is to follow the most permeable path,
a paramagnetic bar places itself lengthwise or parallel with the
prevailing direction of the lines of force so as to carry them as far on
their way as possible. Every other position of the bar is one of
unstable equilibrium or of no equilibrium. The end of the bar where the
lines of force enter (see Lines of Force) is a south pole and is
attracted towards the north pole of the magnet.
The production of magnetic poles under these conditions in the bar is
shown by throwing iron filings upon it. They adhere to both ends but not
to the middle.
Induction, Mutual, Electro-magnetic.
The induction due to two electric currents reacting on each other.