Capacity, Dielectric.
The capacity of a dielectric in retaining an electrostatic charge; the
same as Specific Inductive Capacity. 'The number expressing it is
sometimes called the dielectric constant. (See Capacity, Specific
Inductive.)
Capacity, Electric, or Electrostatic.
The relative capacity of a conductor or system to retain a charge of
electricity with the production of a given difference of potential. The
greater the charge for a given change of potential, or the less the
change of potential for a given charge the greater the capacity. The
measure of its capacity is the amount of electricity required to raise
the potential to a stated amount. The unit of capacity is the farad, q.
v. Electric capacity is comparable to the capacity of a bottle for air.
A given amount of air will raise the pressure more or less, and the
amount required to raise its pressure a stated amount might be taken as
the measure of capacity, and would be strictly comparable to
electrostatic charge and potential change. The capacity, K, is obviously
proportional to the quantity, Q, of the charge at a given potential, E,
and inversely proportional to the potential, E, for a given quantity, Q,
or,
(1) K == Q/E
and
(2) Q = K * E,
or, the quantity required to raise a conductor by a given potential is
equal to the capacity of the conductor or system multiplied by the rise
of potential. The capacity of a conductor depends upon its environments,
such as the nature of the dielectric surrounding it, the proximity of
oppositely charged bodies and other similar factors. (See
Dielectric-Condenser-Leyden jar.)
The dimensions of capacity are found by dividing a quantity of
electricity by the potential produced in the conductor by such
quantity.
Quantity ( ((M^.5)*(L^1.5)) / T ) / potential ( ((M^.5)*(L^.5)) / T ) = L.
Capacity, Instantaneous.
The capacity of a condenser when connected only for an instant to a
source of electricity. This is in contrast to electric absorption (see
Absorption, Electric), and is capacity without such absorption taking
part in the action.