what is principle or capacitor?

A small device used to store huge amount of electric charge in a small room is called capacitor. Take an insulated metal plate A. Charge the plate to its maximum potential. Now take another insulated plate B. Take the plate B nearer to plate A. You will observe that negative charge will be produce on the plate near to plate A and the same amount of positive charge will be produced on the other side of plate B. Now the plate B will start affecting the plate A slowly. The negative charge will start decreasing the electric potential of plate A. But positive charge helps in increasing the potential. But the effect of negative charge is much more than that of the positive because the negative side of plate is near to the plate A. So potential of A will start decreasing and it can be charged again to raise its potential to maximum.

Deep
28 Apr
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6 Answers

jai
08 Jul

Principle of a Capacitor What is a Capacitor It is a device used to store charge in an electrical circuit An every day use To remove sparking in the ignition system of an automobile. When an electric current is switched on or off there is an induced current which can create sparking. If we put a capacitor in the circuit this current charges the capacitor instead and this will avoid occurrence of sparking. Charge is proportional to potential When a charge is given to a conductor its potential rises. If we give a conductor a charge Q then its potential rises. The greater the charge the greater the potential. So they are proprotional to each other and may be exepressed as Q &prop; V Which means that charge Q is directly proportional to potential V or that the potential is directly proportional to the charge given to a conductor We can re-write this as the following equation Q = C V Here C is the capacitance of the conductor Factors determining Capacitance 1. Shape and size of the conductor 2. The surrounding medium 3. Presence of other conductors We can re-write the equation as: C=Q/V Where C is the charge stored per unit potential rise in the conductor SI unit for Capacitance This is Farad 1 Farad = 1 Coulomb/Volt or 1 F = 1 C/V However, Farad is a very large unit so we use smaller units like &mu;F which is 10 -6 F Principle of a Capacitor Say we have a large plate and we give a positive charge to it There is a limit to the amount of charge that can be given to the plate because as charge is given its potential rises and beyond a certain limit the charges start leaking. If we get another plate and place it next to this positively charged plate then negative charge will pulled towards the side of this plate which is closer to the positvely charged plate and positive charge on the further side. This negative charge on plate 2 will reduce the potential on plate 1. At the same time the positive charge on plate 2 will try to increaser the potential of plate 1. However the effect of the closer side of plate 2 holding negative charge will be more. This leads to reduction in the potential of plate 1. So now more charge can be given to plate 1 Now if we earth the outer side of the second plate. Then the positive charge on this side will go to Earth.With this plate 1 will be able to hold even more positive charge. This is the principle of a capacitor

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Principle of a Capacitor
What is a Capacitor
It is a device used to store charge in an electrical circuit
An every day use
To remove sparking in the ignition system of an automobile. When an electric current is switched on or off there is an induced current which can create sparking. If we put a capacitor in the circuit this current charges the capacitor instead and this will avoid occurrence of sparking.
Charge is proportional to potential
When a charge is given to a conductor its potential rises. If we give a conductor a charge Q then its potential rises. The greater the charge the greater the potential. So they are proprotional to each other and may be exepressed as
Q ∝ V
Which means that charge Q is directly proportional to potential V or that the potential is directly proportional to the charge given to a conductor
We can re-write this as the following equation
Q = C V
Here C is the capacitance of the conductor
Factors determining Capacitance
1. Shape and size of the conductor
2. The surrounding medium
3. Presence of other conductors
We can re-write the equation as:
C=Q/V
Where C is the charge stored per unit potential rise in the conductor
SI unit for Capacitance
This is Farad
1 Farad = 1 Coulomb/Volt
or
1 F = 1 C/V
However, Farad is a very large unit so we use smaller units like
μF
which is
10 -6 F
Principle of a Capacitor
Say we have a large plate and we give a positive charge to it
There is a limit to the amount of charge that can be given to the plate because as charge is given its potential rises and beyond a certain limit the charges start leaking.
If we get another plate and place it next to this positively charged plate then negative charge will pulled towards the side of this plate which is closer to the positvely charged plate and positive charge on the further side.

This negative charge on plate 2 will reduce the potential on plate 1. At the same time the positive charge on plate 2 will try to increaser the potential of plate 1. However the effect of the closer side of plate 2 holding negative charge will be more. This leads to reduction in the potential of plate 1. So now more charge can be given to plate 1
Now if we earth the outer side of the second plate. Then the positive charge on this side will go to Earth.With this plate 1 will be able to hold even more positive charge.

This is the principle of a capacitor

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