The field of an isolated point charge varies inversely with squared distance.
Difficulty
Intermediate
Read time
5 min
Prerequisites
Basic algebra, consistent units, and the stated model assumptions
Source
OpenStax, College Physics 2e, §18.4 (Paul Peter Urone and Roger Hinrichs)OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
The field of an isolated point charge varies inversely with squared distance. A positive source produces an outward radial field and a negative source an inward radial field.
| Symbol | Meaning | Units |
|---|---|---|
| Signed radial electric-field component | ||
| Coulomb's Constant | ||
| Signed source charge | ||
| Distance from the source charge |
Find the radial electric field away from a source.
Supply one contribution to a multi-charge field calculation.
Find the radial electric field 0.300 m from a +2.00 µC point charge in vacuum.
OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
Assumptions
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