Core Ratio.
In a telegraph cable the ratio existing between the diameter of the
conducting core and the insulator. To get a ratio approximately accurate
in practical calculations, the diameter of the core is taken at 5 per
cent. less than its actual diameter. The calculations are those
referring to the electric constants of the cable, such as its static
capacity and insulation resistance.
Core, Ribbon.
For discoidal ring-shaped cores of armatures, iron ribbon is often used
to secure lamination and prevent Foucault currents.
Synonym--Tangentially Laminated Core.
Core, Ring.
A core for a dynamo or motor armature, which core forms a complete ring.
Core, Stranded.
In an electric light cable, a conducting core made up of a group of
wires laid or twisted together.
Core, Tubular.
Tubes used as cores for electro-magnets. For very small magnetizing
power, tubular cores are nearly as efficient as solid ones in straight
magnets, because the principal reluctance is due to the air-path. On
increasing the magnetization the tubular core becomes less efficient
than the solid core, as the reluctance of the air-path becomes
proportionately of less importance in the circuit.
Corpusants.
The sailors' name for St. Elmo's Fire, q. v.
Coulomb.
The practical unit of quantity of electricity. It is the quantity passed
by a current of one ampere intensity in one second. It is equal to 1/10
the C. G. S. electro-magnetic unit of quantity, and to 3,000,000,000 C.
G. S. electrostatic units of quantity. It corresponds to the
decomposition of .0935 milligrams of water, or to the deposition of
1.11815 milligrams of silver.
[Transcriber's note: A coulomb is approximately 6.241E18 electrons. Two
point charges of one coulomb each, one meter apart, exerts a force of
900,000 metric tons.]
Coulomb's Laws of Electrostatic Attraction and Repulsion.
1. The repulsions or attractions between two electrified bodies are in
the inverse ratio of the squares of their distance.
2. The distance remaining the same, the force of attraction or repulsion
between two electrified bodies is directly as the product of the
quantities of electricity with which they are charged.