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:
“When complaints are freely heard, deeply considered and speedily reformed, then is the utmost bound of civil liberty attained that wise men look for.”
—John Milton (1608–1674)
“... one of the blind spots of most Negroes is their failure to realize that small overtures from whites have a large significance ... I now realize that this feeling inevitably takes possession of one in the bitter struggle for equality. Indeed, I share it. Yet I wonder how we can expect total acceptance to step full grown from the womb of prejudice, with no embryo or infancy or childhood stages.”
—Sarah Patton Boyle, U.S. civil rights activist and author. The Desegregated Heart, part 1, ch. 10 (1962)
“Those things for which the most money is demanded are never the things which the student most wants. Tuition, for instance, is an important item in the term bill, while for the far more valuable education which he gets by associating with the most cultivated of his contemporaries no charge is made.”
—Henry David Thoreau (1817–1862)