THEORY. A capacitor is a device used extensively in electronic circuits to store electric charge and electric potential energy and to release electric energy. When two conductors have equal and opposite charges, the capacitor is said to be charged. The capacitance of a capacitor is a measure of its capacity for storing charge. The capacitance depends on the geometrical arrangement of the conductors, the physical size and shape of the conductors, and the material medium separating them. The equivalent capacitance of a parallel combination of capacitors is the simple sum of the individual capacitances. The reciprocal of the equivalent capacitance of a series combination of capacitors is the sum of the reciprocals of the individual capacitances.