CAPACITOR

CAPACITOR:

Capacitor is an electronics device which has the capacity to store energy in the form of electric charge. Unlike resistors, capacitors do not restrict the flow of electron. It is a two terminal device and originally known as condenser. The capacitor is made up of two electrically conducting plates separated by dielectrics(insulators). This plates of capacitor is responsible for the accumulation of the electric charges. One plate accumulate the positive charge and other plate accumulate the equal and opposite negative charge.

CAPACITANCE:

Capacitance is the electric charge stored in the capacitor when 1 volt of charge is applied across it.

Capacitance(C) of a capacitor is equal to the ratio of electric charge (Q) and voltage (V).

Mathematically,

                                        

UNIT AND SYMBOL OF RESISTANCE:

The unit of Capacitance is Farad (F). In an electrical or electronics circuit diagram the symbol of capacitor is given in the figure below.

PARALLEL PLATE CAPACITOR:

Parallel plate capacitor is the simplest form of capacitor. It is made up  of two parallel metal plate with dielectrics between them.The capacitance of the parallel plate capacitor is given by,

                                                        

Where, C= Capacitance of parallel plate capacitor.

             e=  permittivity of the dielectric between the plate of capacitor.

             A= Area of plate of parallel plate capacitor

             d= Distance between the plate of the capacitor.

SIMPLE EXPERIMENT TO SHOW THE CHARGE STORE IN CAPACITOR:

This is a simple experiment to show that charge is actually stored in a capacitor. For this experiment we would need a capacitor of high capacitance, a battery and a small bulb or LED. Connect the circuit as shown in figure below. Make sure that capacitor is very large.

When the circuit closes, the bulb will glow as the current flow from battery to capacitor to charge it up. 

Gradually the bulb will grow dimmer and will finally goes off when capacitor reaches its full capacity.

Now if we remove the battery and replace it with the wire, the bulb will again glow as the charge is stored in the capacitor will discharge.

When the capacitor fully discharge, the bulb will turn off.

This experiment proofs that charge is actually stored in a capacitor.

That all about Capacitor. If you have any query or questions leave your question in the comment section.