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Electric field

spatial distribution of vectors representing the force applied to a charged test particle

An electric field is a vector field that shows the direction that a positively charged particle will move when placed in the field. Electric fields are produced around objects that have electrical charge, or by a magnetic field that changes with time. Electric field lines are used to represent the influence of electric field. [1] The idea of an electric field was first made by Michael Faraday.[2]

The formula of electric field is E=F/q where F is force between charge, and q is the test charge.

Electric fields are caused by electric charges, described by Gauss's law,[3] or varying magnetic fields, described by Faraday's law of induction.[4] The equations of both fields are coupled and together form Maxwell's equations that describe both fields as a function of charges and currents.[5]


  1. Richard Feynman (1970). The Feynman Lectures on Physics Vol II. Addison Wesley Longman. ISBN 978-0-201-02115-8.
  2. "Michael Faraday". Retrieved 2015-06-30.
  3. Purcell, p 25: "Gauss's Law: the flux of the electric field E through any closed surface... equals 1/e times the total charge enclosed by the surface."
  4. Purcell, p 356: "Faraday's Law of Induction."
  5. Purcell, Edward & Morin, David 2013. Electricity and magnetism. 3rd ed, Cambridge University Press. New York. ISBN 978-1-107-01402-2