electric field strength

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electric field strength

physics

Also known as: electric field intensity

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June 26, 2026

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An electric field is a property of space that exists around any electric charge. The electric field strength, denoted by E, quantifies this field at any given point. It represents the electric force experienced by a unit positive charge placed at that location.

The electric field is visualized using field lines, which originate from positive charges and terminate on negative charges. The density of these lines indicates the field's strength; closer lines signify a stronger field. The magnitude of the electric field depends on the source charge and the distance from it, diminishing with increased distance. It is also influenced by the medium, being weaker in materials than in a vacuum. Electric fields can propagate as electromagnetic waves when charges accelerate. The units for electric field strength are newtons per coulomb or volts per metre.12

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principles of physical science
Fields
electric field strength due to q₁ at a distance r from q₁ and is designated by E; it is clearly a vector parallel to r. At every point in space E takes a different value, determined by r, and the complete specification of E(r)—that is,…
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electric field strength due to q₁ at a distance r from q₁ and is designated by E; it is clearly a vector parallel to r. At every point in space E takes a different value, determined by r, and the complete specification of E(r)—that is,…
Read More

electric field
…the value of E, called electric field strength or electric field intensity or simply the electric field. Knowledge of the value of the electric field at a point, without any specific knowledge of what produced the field, is all that is needed to determine what will happen to electric charges…
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…the value of E, called electric field strength or electric field intensity or simply the electric field. Knowledge of the value of the electric field at a point, without any specific knowledge of what produced the field, is all that is needed to determine what will happen to electric charges…
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electric susceptibility
…directly proportional to the average electric field strength E so that the ratio of the two, P/E, is a constant that expresses an intrinsic property of the material. The electric susceptibility, χ_e, in the centimetre-gram-second (cgs) system, is defined by this ratio; that is, χ_e = P/E. In the metre-kilogram-second…
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…directly proportional to the average electric field strength E so that the ratio of the two, P/E, is a constant that expresses an intrinsic property of the material. The electric susceptibility, χ_e, in the centimetre-gram-second (cgs) system, is defined by this ratio; that is, χ_e = P/E. In the metre-kilogram-second…
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radiation measurement
Proportional counters
…free electron in a strong electric-field. When the strength of the field is above about 10⁴ volts per centimetre, an electron can gain enough energy between collisions to cause secondary ionization in the gas. After such an ionizing collision, two free electrons exist in place of the original one. In…
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…free electron in a strong electric-field. When the strength of the field is above about 10⁴ volts per centimetre, an electron can gain enough energy between collisions to cause secondary ionization in the gas. After such an ionizing collision, two free electrons exist in place of the original one. In…
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