The action of a capacitor Capacitors store charge and energy. They have many applications, including smoothing varying direct currents, electronic timing circuits and powering the memory to store information in calculators when they are switched off. A capacitor consists of two parallel conducting plates separated by an insulator.
One plate of the capacitor collects a positive charge while the other collects a negative charge, creating an electrostatic field between them. This electrostatic field is the medium through which the capacitor stores energy. The amount of electrical charge that can be stored in the capacitor is determined by the capacitor’s capacitance.
A charged capacitor can supply the energy needed to maintain the memory in a calculator or the current in a circuit when the supply voltage is too low. The amount of energy stored in a capacitor depends on: the voltage required to place this charge on the capacitor plates, i.e. the capacitance of the capacitor.
The charge that a capacitor can store is proportional to the voltage across its plates. When a voltage is applied across the capacitor, the current flows from the voltage source to the capacitor plates. As the capacitor charges up, the current gradually decreases until it reaches zero.
When a voltage is applied to a capacitor, the electric charge accumulates on the plates. One plate of the capacitor collects a positive charge while the other collects a negative charge, creating an electrostatic field between them. This electrostatic field is the medium through which the capacitor stores energy.
The capacitance is the charge gets stored in a capacitor for developing 1 volt potential difference across it. Hence, there is a direct relationship between the charge and voltage of a capacitor. The charge accumulated in the capacitor is directly proportional to the voltage developed across the capacitor.