Electric charge causes potential energy {electric field}| that radiates in all directions. Electric fields can cancel each other, because charges can be positive or negative.
potential
Electric charges q Q make electric force F, which decreases with distance r squared: F = k * q * Q / r^2, where k is electric force constant. Electric-field strength intensity H changes with distance r from charge Q: H = F/q = k * Q / r^2, where k is electric-force constant. Electric field depends on material electric permittivity.
Different distances have different potential energies. Charge can move between two electric-field points, causing potential-energy-change potential difference. Electric-field energy change E is potential difference V times charge q: E = F*s = (k * q * Q / s^2) * s = q * (k * Q / s) = q*V. Potential-energy difference is work done by electric force as charge moves through distance.
examples: surface
Potential is equal all over large charged-object surfaces. Otherwise, electrons flow to lowest-potential location to equalize potential.
examples: plate
Electric field H above charged plates equals charge q divided by electric permittivity k: H = q/k.
examples: rod
Electric field H above long rods varies as reciprocal of distance d from rod: H = C * (1/d).
examples: point
Electric field H around point charges or spheres varies as reciprocal of square of distance r from center: H = k * Q / r^2.
examples: dipole
Electric field H around dipole varies as reciprocal of cube of distance d from dipole center: H = C * (1 / d^3).
Physical Sciences>Physics>Electromagnetism>Energy
5-Physics-Electromagnetism-Energy
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0224