consider a flat plate subject to parallel flow (top and bottom)

Capacitance can also be determined from the dimensions or area, A of the plates and the properties of the dielectric material between the plates. The ability of a capacitor to store a charge on its conductive plates gives it its Capacitance value. So the larger the capacitance, the higher is the amount of charge stored on a capacitor for the same amount of voltage.

Then from above we can define the unit of Capacitance as being a constant of proportionality being equal to the coulomb/volt which is also called a Farad, unit F.Īs capacitance represents the capacitors ability (capacity) to store an electrical charge on its plates we can define one Farad as the “ capacitance of a capacitor which requires a charge of one coulomb to establish a potential difference of one volt between its plates” as firstly described by Michael Faraday. Units of: Q measured in Coulombs, V in volts and C in Farads. Note that capacitance C is ALWAYS positive and never negative. The capacitors ability to store this electrical charge ( Q ) between its plates is proportional to the applied voltage, V for a capacitor of known capacitance in Farads. When a capacitor is fully charged there is a potential difference, (p.d.) between its plates, and the larger the area of the plates and/or the smaller the distance between them (known as separation) the greater will be the charge that the capacitor can hold and the greater will be its Capacitance. Then, a capacitor has the ability of being able to store an electrical charge Q (units in Coulombs) of electrons. When a voltage is applied to these plates an electrical current flows charging up one plate with a positive charge with respect to the supply voltage and the other plate with an equal and opposite negative charge. Capacitance is measured in units of the Farad (F), so named after Michael Faraday.Ĭapacitors consist of two parallel conductive plates (usually a metal) which are prevented from touching each other (separated) by an insulating material called the “dielectric”.

This capacitance value also depends on the dielectric constant of the dielectric material used to separate the two parallel plates.

Capacitance is the measured value of the ability of a capacitor to store an electric charge.

Consider a flat plate subject to parallel flow (top and bottom)