Capacitance is a fundamental concept in the field of electronics and electromagnetism. It refers to the ability of an object or a system to store electric charge when a voltage difference (potential difference) is applied across it. In other words, capacitance is a measure of how much electrical energy can be stored in an electric field between two conductive surfaces or objects.
The basic unit of capacitance is the farad (F), named after the English physicist Michael Faraday. One farad is defined as the capacitance of a system that stores one coulomb of electric charge when a potential difference of one volt is applied across it:
1 farad = 1 coulomb / 1 volt
Capacitance depends on the geometry of the conductive surfaces, the distance between them, and the properties of the material between them (called the dielectric material). Generally, the larger the surface area of the conductive plates and the closer they are together, the higher the capacitance.
Capacitors are components designed to store electrical energy in the form of electric charge. They consist of two conductive plates separated by a dielectric material. When a voltage is applied across the plates, one plate accumulates positive charge while the other accumulates negative charge. This creates an electric field between the plates, and the amount of charge stored per unit voltage (potential difference) is the capacitance.
Capacitance has numerous practical applications in electronics, such as in smoothing power supplies, filtering signals, timing circuits, and more. It also plays a critical role in communication systems, energy storage devices, and many other areas of technology.