Forces, Resolution of.
The developing from a single force treated as a resultant, two other
forces in any desired direction. The reverse of composition of forces.
(See Forces, Composition of--Forces, Parallelogram
of--Components--Resultant.)
Force, Tubes of.
Aggregations of lines of force, either electrostatic or magnetic. They
generally have a truncated, conical or pyramidal shape and are not
hollow. Every cross-section contains the same number of lines. The name
it will seem is not very expressive.
Force, Unit of.
The fundamental or C. G. S. unit or force is the dyne, q. v.
The British unit of force is the poundal (the force which will produce
an acceleration of one foot per second in a mass of one pound). It is
equal to about 10/322 pound. A force cannot be expressed accurately in
weight units, because weight varies with the latitude.
Forming.
The process of producing secondary battery plates from lead plates by
alternately passing a charging current through the cell and then
allowing it to discharge itself and repeating the operation. (See
Battery, Secondary, Planté's.)
Foundation Ring.
In a dynamo armature the ring-shaped core on which Gramme ring armatures
and other ring armatures are wound.
Fourth State of Matter.
Gas so rarefied that its molecules do not collide, or rarely do so;
radiant matter, q. v.
[Transcriber's note: This term now refers to plasma, an ionized gas,
which contains free electrons. The ions and electrons move somewhat
independently making plasma electrically conductive. It responds
strongly to electromagnetic fields.]
Frame.
In a dynamo the bed-piece is sometimes called the frame.
Franklin's Experiment.
Franklin proved the identity of lightning and electricity by flying a
kite in a thunder storm. The kite was of silk so as to endure the
wetting. When the string became wet sparks could be taken from a key
attached to its end. The main string was of hemp; at the lower end was a
length of silk to insulate it. The key was attached near the end of and
to the hemp string.
Franklin's Plate.
A simple form of condenser. It consists of a plate of glass coated on
each side with tinfoil with a margin of about an inch of clear glass.
One coating may be grounded as indicated in the cut, and the plate
charged like a Leyden jar. Or one side may be connected with one
terminal, and the other with the other terminal of an influence machine
and the pane will be thus charged.
Synonym--Fulminating Pane.