Potential

Potential

Potential DifferenceThe potential difference between the points A and B is defined as the work done to move a unit charge from point A to point B

Work done( ) to move the charge for small distance :

Work done = Force x DistanceTotal Work done (W) to move the charge from A to B:

Work done to move unit charge from A to B is potential difference between A and B

We know that

..1

- a charge which create the electric field E

- Potential at a point A- Potential at a point B

Eqn2 ,Eqn.3 in Eqn.1

From Fig.1

.3;

..2

Potential Difference

The potential difference between the points A and B is defined as the work done to move the unit charge from A to B

Work done to move the charge for small distance

Work done = Force x DistanceTotal Work done to move the charge from A to B

- Potential at a point A- Potential at a point BVoltWork done to move unit charge from A to B is potential difference between A and B

Potential or Absolute PotentialPotential at any point is defined as the work done to move a unit positive charge from infinite to a that point in an electric field (E)

Potential difference between a point A and B:

...1To find potential (V) at point B substitute in Eqn. 1

- a charge which create the electric field E

Total change (dv )in V(x,y,z) is the sum of partial changes ( ) with respect to x,y,z.

Relation between Electric field and potential (E and V)We know that. 1. 2Compare 1 and 2

Electric Dipole The two equal and opposite charges ,which are separated by a small distance, is called electric -dipole or dipole.Dipole Moment(M)It is defined as the product of charge(Q) and distance (d)between the charges

Potential and Electric field intensity due to an electric dipoleConsider a positive and negative point charges separated by a distance d.Position of the charges and are (0,0,d/2) and (0,0,-d/2) respectively.The potential at point P is the sum of potential due to individual charges at that point

- distance between charge and point P- distance between charge and point P

If the point is far away from the charges the difference between and is negligible.

This approximation may not be made in the numerator

In spherical co-ordinate system

We know that14Eqn.2 ,Eqn.3 in Eqn.1235

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9Eqn.7,Eqn.8,Eqn.9 in Eqn.6