Electric field due to dipole
============================

The strength of the electric field set up by a dipole at a distant point on the dipole axis,
which runs through both point charges comprising the dipole, is proportional to the inverse
cube of the distance to the dipole and the value of the electric dipole moment.

**Notation:**

#. :math:`\varepsilon_0` (:code:`epsilon_0`) is :attr:`~symplyphysics.quantities.vacuum_permittivity`.

**Conditions:**

#. :math:`r / d \gg 1` where :math:`d` is the distance between point charges of the
   dipole. This means that the point where electric field is measured must be far enough
   from the dipole itself.

**Links:**

#. `Wikipedia <https://en.wikipedia.org/wiki/Electric_dipole_moment#Potential_and_field_of_an_electric_dipole>`__.

.. py:currentmodule:: symplyphysics.laws.electricity.electric_field_due_to_dipole

.. py:data:: electric_field_strength

    :attr:`~symplyphysics.symbols.electrodynamics.electric_field_strength` due to dipole.

Symbol:
    :code:`E`

Latex:
    :math:`E`

Dimension:
    :code:`voltage/length`


.. py:data:: electric_dipole_moment

    See :doc:`laws.electricity.electric_dipole_moment_is_charge_times_distance` and
    :attr:`~symplyphysics.symbols.electrodynamics.electric_dipole_moment`.

Symbol:
    :code:`p`

Latex:
    :math:`p`

Dimension:
    :code:`charge*length`


.. py:data:: distance

    :attr:`~symplyphysics.symbols.classical_mechanics.euclidean_distance` to dipole.

Symbol:
    :code:`d`

Latex:
    :math:`d`

Dimension:
    :code:`length`


.. py:data:: law

    :code:`E = p / d^3 / (2 * pi * epsilon_0)`


    Latex:
        .. math::
            E = \frac{1}{2 \pi \varepsilon_0} \frac{p}{d^{3}}