Electric field

Electric field
Effects of an electric field. The girl is touching an electrostatic generator, which charges her body with a high voltage. Her hair, which is charged with the same polarity, is repelled by the electric field of her head and stands out from her head.
Common symbols
E
SI unitvolt per meter (V/m)
In SI base unitskg⋅m⋅s−3⋅A−1
DimensionM L T−3 I−1

An electric field (sometimes called E-field[1]) is the physical field that surrounds electrically charged particles. Charged particles exert attractive forces on each other when their charges are opposite, and repulse each other when their charges are the same. Because these forces are exerted mutually, two charges must be present for the forces to take place. The electric field of a single charge (or group of charges) describes their capacity to exert such forces on another charged object. These forces are described by Coulomb's law, which says that the greater the magnitude of the charges, the greater the force, and the greater the distance between them, the weaker the force. Thus, we may informally say that the greater the charge of an object, the stronger its electric field. Similarly, an electric field is stronger nearer charged objects and weaker further away. Electric fields originate from electric charges and time-varying electric currents. Electric fields and magnetic fields are both manifestations of the electromagnetic field, Electromagnetism is one of the four fundamental interactions of nature.

Electric fields are important in many areas of physics, and are exploited in electrical technology. For example, in atomic physics and chemistry, the interaction in the electric field between the atomic nucleus and electrons is the force that holds these particles together in atoms. Similarly, the interaction in the electric field between atoms is the force responsible for chemical bonding that result in molecules.

The electric field is defined as a vector field that associates to each point in space the force per unit of charge exerted on an infinitesimal test charge at rest at that point.[2][3][4] The SI unit for the electric field is the volt per meter (V/m), which is equal to the newton per coulomb (N/C).[5]

  1. ^ Roche, John (2016). "Introducing electric fields". Physics Education. 51 (5): 055005. Bibcode:2016PhyEd..51e5005R. doi:10.1088/0031-9120/51/5/055005. S2CID 125014664.
  2. ^ Feynman, Richard (1970). The Feynman Lectures on Physics Vol II. Addison Wesley Longman. pp. 1–3, 1–4. ISBN 978-0-201-02115-8.
  3. ^ Purcell, Edward M.; Morin, David J. (2013). Electricity and Magnetism (3rd ed.). New York: Cambridge University Press. pp. 15–16. ISBN 978-1-107-01402-2.
  4. ^ Cite error: The named reference Serway was invoked but never defined (see the help page).
  5. ^ Le Système international d’unités [The International System of Units] (PDF) (in French and English) (9th ed.), International Bureau of Weights and Measures, 2019, ISBN 978-92-822-2272-0, p. 23