Electric Constant

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electric constant

[i¦lek·trik ′kän·stənt]
The permittivity of empty space, equal to 1 in centimeter-gram-second electrostatic units and to 107/4π c 2 farads per meter or, numerically, to 8.854 × 10-12 farad per meter in International System units, where c is the speed of light in meters per second. Symbolized ε0.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Electric Constant


(or permittivity of free, or empty, space), the constant of proportionality ∊0 in Coulomb’s law, which gives the force of interaction between two point charges at rest.

In the International System of Units (SI), ∊0 = 10 7/4πC 2 farads per meter (F/m) = 8.85418782 ± 0.00000007 F/m, where c is the speed of light in m/sec. In the centimeter-gram-second (cgs) electrostatic system and in the Gaussian system, ∊0 is taken to be a dimensionless factor equal to unity.

In contrast to the dielectric constant ∊, which depends on the type of substance, temperature, pressure, and other parameters, the electric constant ∊0 depends only on the choice of a system of units.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The actual permittivity, , is then calculated by multiplying the relative permittivity by the electric constant, o (vacuum permittivity): = = (1+ ), where is the electric susceptibility of the seed.
The Prep 250 electric constant pressure column-packing pump delivers flows to 250 mL/min and handles system pressures up to 7500 psi (517 bar).
where [epsilon]0 is the electric constant, [epsilon] is the relative dielectric constant of insulation; [epsilon]0 = 1/[[mu].sub.0] [c.sup.2.sub.0] = 8.85 x [10.sup.-12] F/m; [c.sub.0] = 2.99 ...
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--the value 4[pi][[epsilon].sub.0], which in SI units is 1.11 x [10.sup.-10] Farad/metre, is replaced by a new electric constant s0 = [m.sub.e]/[r.sub.e] = 3.23 x [10.sup.-16] [kg/m];
where B is the magnetic flux density vector; A is the vector magnetic potential; [nabla]V is scalar electric potential difference; [[mu].sub.x] is relative permeability; [[mu].sub.0] = 4[pi] x [10.sup.-7]H/m is magnetic constant; sr is relative permittivity; [[epsilon].sub.0]=8,85 x [10.sup.-12] F/m is electric constant.
In Japan and Russia, scientists are levitating masses with superconductors; in Germany, experimenters are debugging a vacuum Faraday system, whereby gold atoms beamed onto a collector yield an electric constant, from which an Avogadro number can be derived.
where [z.sub.1] and [z.sub.2] are the numbers of the electric charges, c is the velocity of light, [m.sub.e] is the electron's mass, while [epsilon] = [m.sub.e]/[r.sub.e] is a new electric constant, which is 3.23 x [10.sup.-16] kg/m and is the linear density of the vortical tube.