A capacitor can store energy in the form of potential energy in an
electric field. In this chapter we'll discuss the capacity of conductors
to hold charge and energy.
CAPACITANCE OF AN ISOLATED CONDUCTOR
When a conductor is charged its potential increases. It is found that for an isolated conductor (conductor
should be of finite dimension, so that potential of infinity can be assumed to be zero) potential of the
conductor is proportional to charge given to it.
Work done in charging the conductor to the charge on it against its own electric field or total energy stored
in electric field of conductor is called self energy or self potential energy of conductor
CAPACITANCE OF AN ISOLATED SPHERICAL CONDUCTOR
SHARING OF CHARGES ON JOINING TWO CONDUCTORS (BY A
CONDUCTING WIRE)
A capacitor or condenser consists of two conductors separated by an insulator or dielectric.
When uncharged conductor is brought near to a charged conductor, the charge on conductors
CIRCUIT SOLUTION FOR R–C CIRCUIT AT t = 0 (INITIAL STATE)
AND AT t = ? (FINAL STATE)
DISTRIBUTION OF CHARGES ON CONNECTING TWO CHARGED
CAPACITORS
Derivation of above formulae
When initially uncharged capacitors are connected as
shown then the combination is called series combination
Derivation of Formulae
When one plate of each capacitors (more than one) is
connected together and the other plate of each capacitor
is connected together, such combination is called parallel
combination
The combination which contains mixing of series parallel
combinations or other complex combinations fall in mixed
category
Charging of a condenser :
(i) In the following circuit. If key 1 is closed then the condenser gets
charged. Finite time is taken in the charging process. The quantity of
After one time constant
Method for objective
In any circuit when there is only one capacitor then
When a dielectric fills the space between the plates then molecules having dipole moment align themselves
in the direction of electric field.
CAPACITORS WITH DIELECTRIC
CAPACITORS WITH DIELECTRIC
OTHER TYPES OF CAPACITORS
Spherical capacitor :
This arrangement is known as spherical capacitor
