*ELECTROSTATIC POTENTIAL AND CAPACITANCE

ELECTROSTATIC POTENTIAL

Work done in bringing a unit +ve charge from infinity to any point in the electrostatic field

V=kΣQi/Ri

V=kQ/r

1 VOLT

One joule of work done to move 1 coulomb of charge from infinity to the point against ES force

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due to a point charge

due to dipole

EOUIPOTENTIAL SURFACES

ELECTRIC POTENTIAL ENERGY

Surfaces with constant potential value at all point on the surface. (parallel component of electric field is 0)

The electric potential energy of any given charge or system of changes is termed as the total work done by an external agent in bringing the charge or the system of charges from infinity to the present configuration without undergoing any acceleration.

kQq/r

The potential difference between points A & B :
Vb-Va=(Ub-Ua)/q

Electric potential energy of an Electric dipole in dipole from zero energy position to the desired position (The zero energy position to be one when the dipole When an electric dipole of dipole moment p is on it such that P= P​× E​ This torque tends to rotate the dipole let dW the small amount of work done.

potential energy of a dipole

Capacitance

C=Q/V

Due to system of charges

Capacitance for isolated sphere

4πε0R

Capacitance when metal slab inserted

kε0A[kd-x(k-1)]

Capacitance for parallel plate capacitor

Kε0A/d
K=εr(dielectric constant

Energy stored in a capacitor

U=(Q^2)/2C