Free, Bound and Total Charge
In dielectric materials, the total charge of an object can separated into "free" and "bound" charges.
Bound charges set up electric dipoles in response to an applied electric field E, and polarize other nearby dipoles tending to line them up, the net accumulation of charge from the orientation of the dipoles is the bound charge. They are called bound because they cannot be removed: in the dielectric material the charges are the electrons bound to the nuclei.
Free charges are the excess charges which can move into electrostatic equilibrium, i.e. when the charges are not moving and the resultant electric field is independent of time, or constitute electric currents.
Read more about this topic: Charge Density
Famous quotes containing the words bound, total and/or charge:
“I ask you to join in a re-United States. We need to empower our people so they can take more responsibility for their own lives in a world that is ever smaller, where everyone counts.... We need a new spirit of community, a sense that we are all in this together, or the American Dream will continue to wither. Our destiny is bound up with the destiny of every other American.”
—Bill Clinton (b. 1946)
“Parenthood always comes as a shock. Postpartum blues? Postpartum panic is more like it. We set out to have a baby; what we get is a total take-over of our lives.”
—Polly Berrien Berends (20th century)
“To fight aloud is very brave,
But gallanter I know,
Who charge within the bosom
The Cavalry of Woe.”
—Emily Dickinson (1830–1886)