Magnet, Deflection of.
The change of position of a magnet from the plane of the earth's
meridian in which it normally is at rest into another position at some
angle thereto, by the effect of an artificial magnetic field, as the
deflection of a galvanometer needle.
Magnet, Electro-.
A magnet consisting of a bar of iron, bundle of iron wires, iron tube or
some equivalent, around which a coil of insulated wire is wound. Such
combination becomes polarized when a current is passed through it and is
an active magnet. On the cessation of the current its magnetism in part
or almost completely disappears. (See Electro-magnet.)
Magnet, Equator of.
In a magnet the locus of points of no attractive power and of no
polarity. In a symmetrical, evenly polarized magnet it is the imaginary
line girdling the centre. The terms Neutral Point or Neutral Line have
displaced it.
Synonyms--Neutral Line--Neutral Point.
Magnet, Field.
A magnet, generally an electro-magnet, used to produce the field in a
dynamo or motor.
Magnet, Haarlem.
Celebrated magnets made in Haarlem, Holland. Logeman, Van Wetteren,
Funckler and Van der Willigen were the makers who gave the celebrity to
the magnets. They were generally horseshoe magnets, and would carry
about twenty times their own weight.
Magnet, Horseshoe.
A magnet of U shape--properly one with the poles brought a little closer
together than the rest of the limbs. For direct lifting and attractive
effects it is the most generally adopted type. Its advantage as regards
lifting effect is due to small reluctance, q. v., offered by a complete
iron circuit, such as the armature and magnet together produce. As the
term is now used it is applied to any U shaped magnet.
Fig. 218. JOULE'S ELECTRO-MAGNET.
Magnet, Joule's Electro.
An electro-magnet of the shape of a cylinder with a longitudinal segment
cut-off. It is wound with wire as shown. The segment cut-off is a piece
of the same shape as the armature. It is of high power.