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Electricity

Electric Fields



Charged particles alter their surrounding space to produce an effect called an electric field. An electric field is the concept we use to describe how one electric charge exerts force on another distant electric charge. Whether electric charges are at rest or moving, they are acted upon by a force whenever they are within an electric field. The ratio of this force to the amount of charge is the measure of the field's strength.



An electric field has vector properties in that it has both a unique magnitude and direction at every point in space. An electric field is the collection of all these values. When neighboring electrical charges push or pull each other, each interacts with the electric field produced by the other charge.

Electric fields are imagined as lines of force that begin on positive charges and end on negative charges. Unlike magnetic field lines, which form continuous loops, electric field lines have a beginning and an ending. This makes it possible to block the effects of an electric field. An electrically conducting surface surrounding a volume will stop an external electric field. Passengers in an automobile may be protected from lightning strikes because of this shielding effect. An electric shield enclosure is called a Faraday cage, named for Michael Faraday.

Electricity arcing over the surface of ceramic insulators. Photograph by Robert Essel/Bikderberg. Stock Market. Reproduced with permissions.

Additional topics

Science EncyclopediaScience & Philosophy: Dysprosium to Electrophoresis - Electrophoretic TheoryElectricity - Electrical Charge, Electric Fields, Coulomb's Law And The Forces Between Electrical Charges, Resistance - Current, Voltage, Ohm's law