Electric Field and Coulomb

Stationary electric charge creates static electric field (like mass creates gravitational field).

The geometry of the field depends on the geometry and charge distribution (point, (-s), sphere, line, plate, dipole...)

E-field is described by field lines (here point charges):

• At any point the direction of E-field is a) tangential to field line b) equal to the direction of electric force experienced by a tiny positive test charge.


• Strenth of the field corresponds to the density of field lines.

Coulomb law gives the strength of electric force between two point or spherical charges. Try here if the force obeys Coulomb law.