Conservation of Electric Charge
The total electric charge of an isolated system remains constant regardless of changes within the system itself. This law is inherent to all processes known to physics and can be derived in a local form from gauge invariance of the wave function. The conservation of charge results in the charge-current continuity equation. More generally, the net change in charge density within a volume of integration is equal to the area integral over the current density through the closed surface, which is in turn equal to the net current :
Thus, the conservation of electric charge, as expressed by the continuity equation, gives the result:
The charge transferred between times and is obtained by integrating both sides:
where is the net outward current through a closed surface and is the electric charge contained within the volume defined by the surface.
Read more about this topic: Electric Charge
Famous quotes containing the words conservation of, conservation, electric and/or charge:
“A country grows in history not only because of the heroism of its troops on the field of battle, it grows also when it turns to justice and to right for the conservation of its interests.”
—Aristide Briand (1862–1932)
“A country grows in history not only because of the heroism of its troops on the field of battle, it grows also when it turns to justice and to right for the conservation of its interests.”
—Aristide Briand (1862–1932)
“The more I see of democracy the more I dislike it. It just brings everything down to the mere vulgar level of wages and prices, electric light and water closets, and nothing else.”
—D.H. (David Herbert)
“One can only call that youth healthful which refuses to be reconciled old ways and which, foolishly or shrewdly, combats the old. This is nature’s charge and all progress hinges upon it.”
—Anton Pavlovich Chekhov (1860–1904)