Magnetic Force.
The forces of attraction and repulsion exercised by a magnet. By
Ampere's theory it is identical with the forces of attraction and
repulsion of electric currents.
Magnetic Friction.
The damping effect produced on the movements of a mass of metal by
proximity to a magnet; the phenomenon illustrated in Arago's wheel, q.
v. When a mass of metal moves in the vicinity of a magnet it cuts the
lines of force emanating from its poles, thereby producing currents in
its mass; as the production of these currents absorbs energy a damping
effect is produced upon the movements of the mass.
Magnetic Gear.
Friction gear in which electro-magnetic adherence is employed to draw
the wheels together. (See Adherence, Electro-magnetic--Electro-magnetic
Friction Gear.)
Magnetic Inclination.
The inclination from the horizontal of a magnetic needle placed in the
magnetic meridian. (See Magnetic Element--Inclination Map.)
Synonym--Magnetic Dip.
Magnetic Induction.
The force of magnetization within an induced magnet. It is in part due
to the action of the surrounding particles of polarized material; in
part to the magnetic field. (See Magnetic Induction, Coefficient of.)
In a more general way it is the action of a magnet upon bodies in its
field of force. In some cases the magnetism induced causes the north
pole of the induced magnet to place itself as far as possible from the
north pole of the inducing magnet and the same for the south poles. Such
substances are called paramagnetic or ferromagnetic. They lie parallel
or tangential to the lines of force. In other cases the bodies lie at
right angles or normal to the lines of force. Such bodies are called
diamagnetic.
Some bodies are crystalline or not homogeneous in structure, and in them
the lines of magnetic induction may take irregular or eccentric paths.
(See AEolotropic.)
Synonym--Magnetic Influence.
Magnetic Induction, Apparent Coefficient of.
The apparent permeability of a paramagnetic body as affected by the
presence of Foucault currents in the material itself. These currents act
exactly as do the currents in the coils surrounding the cores of
electro-magnets. They produce lines of force which may exhaust the
permeability of the iron, or may, if in an opposite direction, add to
its apparent permeability.
Magnetic Induction, Coefficient of.
The number, obtained by dividing the magnetization of a body, expressed
in lines of force produced in it, by the magnetizing force which has
produced such magnetization, expressed in lines of force producible by
the force in question in air. It always exceeds unity for iron, nickel
and cobalt. It is also obtained by multiplying the coefficient of
induced magnetization by 4 PI (4 * 3.14159) and adding 1. (See Magnetic
Susceptibility--Magnetization, Coefficient of Induced.)