electric field

(redirected from Electrical fields)
Also found in: Dictionary, Thesaurus, Medical.
Related to Electrical fields: Coulomb's Law

electric field

a field of force surrounding a charged particle within which another charged particle experiences a force
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

Electric field

A condition in space in the vicinity of an electrically charged body such that the forces due to the charge are detectable. An electric field (or electrostatic field) exists in a region if an electric charge at rest in the region experiences a force of electrical origin. Since an electric charge experiences a force if it is in the vicinity of a charged body, there is an electric field surrounding any charged body.

The electric field intensity (or field strength) E at a point in an electric field has a magnitude given by the quotient obtained when the force acting on a test charge q placed at that point is divided by the magnitude of the test charge q. Thus, it is force per unit charge. A test charge q is one whose magnitude is small enough so it does not alter the field in which it is placed. The direction of E at the point is the direction of the force F on a positive test charge placed at the point. Thus, E is a vector point function, since it has a definite magnitude and direction at every point in the field, and its defining equation is Eq. (1).

Electric flux density or electric displacement D in a dielectric (insulating) material is related to E by either of the equivalent equations shown as Eqs. (2),
where P is the polarization of the medium, and ε is the permittivity of the dielectric which is related to ε 0, by the equation ε = k ε 0, k being the relative dielectric constant of the dielectric. In empty space, D = ε 0 E .

In addition to electrostatic fields produced by separations of electric charges, an electric field is also produced by a changing magnetic field. See Electric charge, Electromagnetic induction, Potentials

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Electric Field


a particular manifestation, along with the magnetic field, of an electromagnetic field that determines the effects upon an electric charge of a force that is independent of the velocity of the charge (see).

The concept of electric field was introduced into science by M. Faraday in the 1830’s. According to Faraday, each stationary charge creates an electric field in the surrounding space. The field of one charge acts upon another charge and vice versa, and an interaction between charges occurs (concept of short-range action). The principal quantitative characteristic of an electric field is its intensity E, defined as the ratio of the force F acting upon the charge to the magnitude of the charge q:E = F/q (seeFIELD INTENSITY, ELECTRIC). The electric field in a medium is characterized not only by its intensity but also by the electric induction vector (seeINDUCTION, ELECTRICAL AND MAGNETIC). The distribution of an electric field in space is visually represented by the intensity lines of force (seeLINES OF FORCE). The lines of force of a potential electric field that is created by electric charges originate on positive charges and terminate on negative charges. The lines of force of a rotational electric field, that is, an electric field created by a changing magnetic field, are closed curves.

The intensity of an electric field satisfies the principle of superposition, according to which for a given point in space, the intensity of the field E, created by several charges, is equal to the sum of the field intensities (E1, E2, E3, . . . .) of the individual charges: E = E1 + E2 + E3 + . . . . The superposition of fields follows from the linearity of Maxwell’s equations (seeMAXWELL’S EQUATIONS).


Tamm I. E. Osnovy teorii elektrichestva, 9th ed. Moscow, 1976. Chapters 1 and 6.
Kalashnikov S. G. Elektrichestvo, 4th ed. Moscow, 1977. (Obshchii kura fiziki.) Chapters 2 and 13.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

electric field

[i¦lek·trik ′fēld]
One of the fundamental fields in nature, causing a charged body to be attracted to or repelled by other charged bodies; associated with an electromagnetic wave or a changing magnetic field.
Specifically, the electric force per unit test charge.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Under the action of electrical field, the barrier [DELTA]G decreases with the square of the field due to an electromechanical modification of the intrinsic free energy barrier.
The defect in non-uniform electrical field (E [not equal to] const) is affected by voltage
In the same water content and EPD conditions (time and electrical field), deposition rate increases in the order of methanol > ethanol > isopropanol, which is in agreement with the values of mobility for chitosan in these solutions.
EDW used electrical field to drive charged jet injection from the tip of Taylor cone below the spinneret, and the diameter of charged jet is significantly smaller than the inner diameter of the spinneret.
In his new position, Gago will be responsible for developing international sales of the NanoKnife, a surgical technique using electrical fields based on IRE technology.
From the physical idea of mass, from the idea of the resultant vector (EV) as electric flux [not member of] and from the ideas relating to the magnetic monopole (MMP) it follows that the gravitational field is an electrical field. The share of the electrical gravitational flux [[not member of].sub.[GAMMA]] on the entire electrical flux [not member of] of a quark is determined from Newton's empirical gravitational constant G.
A study published in the journal Atmospheric Environment in August of 2007 describes how electrical fields from computers, cell phones, Wi-Fi systems and everyday household devices can give people asthma, influenza and other respiratory diseases.
The treatment involves the use of a special device that sends continuous electrical fields to the tumor site through electrodes attached to the scalp.
Danger of electrical fields. From this point, the discussion involves only process-essential insulators, as S20.20 requires electrical bonding of all conductors (includes personnel) and grounding when possible, as well as removal of all nonessential insulators.
The international, multi-center trial will compare the best standard treatments -- surgical removal of the tumor, radiotherapy or chemotherapy -- to that treatment combined with a new, noninvasive therapy that provides alternating electrical fields directly to the surface of the head.
SIR - After reading of cases of people living near wind farms becoming ill for unknown reasons, I found it interesting to read of the official reports of so-called 'electronic smog', which state that wiring creates electrical fields, one component of the smog.
The measurement facility gives the total amplitude of the electrical fields. These measurements are compared to results obtained from the IE3D computer program used.