A capacitor or a capacitor is a passive electronic component composed of a pair of conductors separated by a dielectric. When a voltage potential difference between conductors, an electric field is present in the dielectric. This energy is stored and produces a mechanical force between the plates. The effect is greatest among the great, flat, parallel, conductors strictly separated.
An ideal capacitor is characterized by a single constant value, capacity, measured in farads. This is why the electric charge on each conductor to the potential difference between them. In practice, the dielectric between the plates passes a small amount of leakage current. Drivers and led to introduce an equivalent resistance of the series and the dielectric has a maximum electric field strength resulting from the breakdown voltage.
The capacitors are widely used in electronic circuits to block current flow in alternating current while allowing pass interference filters, to smooth the production of electricity, and for many other purposes. Resonant circuits are used in radio frequency equipment to select specific frequencies from a signal with many frequencies.