A capacitor is an essential electronic component that stores electrical energy in the form of an electric field. It consists of two parallel plates separated by a dielectric material. The symbol commonly used to represent a capacitor in circuit diagrams is two short parallel lines with a gap between them.
A capacitor consists of two metal plates separated by a dielectric. A capacitor is capable of storing electrical charge and energy. The higher the value of capacitance, the more charge the capacitor can store. The larger the area of the plates or the smaller their separation the more charge the capacitor can store.
Capacitors that have both of their respective terminals connected to each terminal of another capacitor are said to be connected in Parallel. Parallel connected capacitors have a common supply voltage across them. Series connected capacitors have a common current flowing through them.
Figure 8.3.1 8.3. 1: (a) Three capacitors are connected in series. The magnitude of the charge on each plate is Q. (b) The network of capacitors in (a) is equivalent to one capacitor that has a smaller capacitance than any of the individual capacitances in (a), and the charge on its plates is Q.
Charge on this equivalent capacitor is the same as the charge on any capacitor in a series combination: That is, all capacitors of a series combination have the same charge. This occurs due to the conservation of charge in the circuit.
If this simple device is connected to a DC voltage source, as shown in Figure 8.2.1 , negative charge will build up on the bottom plate while positive charge builds up on the top plate. This process will continue until the voltage across the capacitor is equal to that of the voltage source.