**Field From An Electric Dipole**

The electrostatic potential at position **r** due to an electric dipole at the origin is given by:

where

- is a unit vector in the direction of
*r'*,**p**is the (vector) dipole moment, and*ε*_{0}is the permittivity of free space.

This term appears as the second term in the multipole expansion of an arbitrary electrostatic potential Φ(**r**). If the source of Φ(**r**) is a dipole, as it is assumed here, this term is the only non-vanishing term in the multipole expansion of Φ(**r**). The electric field from a dipole can be found from the gradient of this potential:

where **E** is the electric field and *δ*3 is the 3-dimensional delta function. This is formally identical to the magnetic **H** field of a point magnetic dipole with only a few names changed.

Read more about this topic: Dipole

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