Basically, a capacitor consists of two parallel conductive plates separated by insulating material. Due to this insulation between the conductive plates, the charge/current cannot flow between the plates and is retained at the plates. The plates may be of different shapes like rectangle, square, circular, and. The image below is showing a simple circuit to show how capacitor charging and discharging takes place in a circuit. As the changeover switch moves towards the battery positive terminal. As we know that when a voltage source is connected to conductor it gets charged say by a value Q. And since the charge is proportional to the voltage applied, we can say that: Q∝V In order to equate the charge Q and voltage V. Q=CV, where C is the capacitance of the. Capacitors are used in almost every field of electronics, and play a very significant role in power circuits as well. Depending on the application we may use different types of capacitors for. The standard unit of capacitance is Farad, named after scientist Michael Faraday. 1 Farad=1 coulomb/volt Farad is a very large unit, in practice, we generally use smaller units like Nano farads, Pico farads, Micro farads, etc.