Ampere, Arc.
A conductor bent into the arc of a circle, and employed in measuring the
electric current by the electric balance.
Ampere-currents.
The currents assumed to be the cause of magnetism. (See Magnetism,
Ampere's Theory of.)
Ampere-feet.
The product of amperes of current by the length, in feet, of a conductor
passing such current. It may be in empiric calculations of dynamo or
motor construction, but is little used. One ampere-foot is a current of
one ampere passing through one foot length of a conductor, or one-tenth
ampere through ten feet, and so on.
Ampere-hour.
The quantity of electricity passed by a current of one ampere in one
hour. It is used by electric power and lighting companies as the unit of
energy supplied by them, because they maintain a constant potential
difference in their leads, so that only the amperes and hours need
measuring or recording to give the energy, viz. : volt-ampere-hours.
The same unit is applied to batteries to indicate their potential
energy, because they also are assumed to be of constant voltage or
electro-motive force.
Ampere-meters.
The product of amperes of current by the length, in meters, of a
conductor carrying such current. One ampere-meter is a current of one
ampere passing through one meter of a conductor.
The term must not be confused with the identically spelled Ampere-meter,
a synonym for Ammeter.
Ampere-minute.
The quantity of electricity passed by a current of one ampere in one
minute; sixty coulombs.
Ampere Ring.
A conductor forming a ring or circle used in electric balances for
measuring currents. (See Balance, Ampere.)
Ampere-second.
The quantity of electricity passed by a current of one ampere in one
second; the coulomb, q. v.
Amperes, Lost.
In a shunt or compound-wound dynamo, part of the total amperes of
current produced in the armature coils go through the shunt, and hence,
do not appear in the outer circuit. S. P. Thompson has proposed the term
"lost amperes" for this portion of the current.
Ampere's Memoria Technica.
An expression of the effect of a current on a magnetic needle. If we
imagine the observer in the line of the current and facing the magnetic
needle, the current entering by his feet and leaving by his head, the
north pole is deflected to his left.