Quantity of
charge is proportional to to
potential; that is, Q = CE, where Q is the quantity of charge in
coulombs, E is the potential in volts, and C is a constant called the
capacitance of the
charged object. The unit of capacitance is the farad. Capacitance increases with the
size of the object, and also increases if the
charge is distributed between two conductors by induction, if the
conductors are insulated from each other. (This is because for the same
total quantity of electricity the potential, E, is lowered by the presence of the nearby
induced charge of
opposite polarity.)