Capacitance of spherical capacitor
==================================

A spherical capacitor is composed of two concentric spheres with the space between them
filled with a dielectric medium. See `Figure`_.

.. _Figure: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capsph.html

**Links:**

#. `Physics Bootcamp, formula 34.3.1 <http://www.physicsbootcamp.org/Spherical-Capacitor.html>`__.

.. py:currentmodule:: symplyphysics.laws.electricity.circuits.capacitance_of_spherical_capacitor

.. py:data:: capacitance

    :attr:`~symplyphysics.symbols.electrodynamics.capacitance` of the capacitor.

Symbol:
    :code:`C`

Latex:
    :math:`C`

Dimension:
    :code:`capacitance`


.. py:data:: absolute_permittivity

    :attr:`~symplyphysics.symbols.electrodynamics.absolute_permittivity` of the medium between the spheres.

Symbol:
    :code:`epsilon`

Latex:
    :math:`\varepsilon`

Dimension:
    :code:`capacitance/length`


.. py:data:: inner_radius

    Radius of the inner sphere. See :attr:`~symplyphysics.symbols.classical_mechanics.distance_to_origin`.

Symbol:
    :code:`r_in`

Latex:
    :math:`r_\text{in}`

Dimension:
    :code:`length`


.. py:data:: outer_radius

    Radius of the outer sphere. See :attr:`~symplyphysics.symbols.classical_mechanics.distance_to_origin`.

Symbol:
    :code:`r_out`

Latex:
    :math:`r_\text{out}`

Dimension:
    :code:`length`


.. py:data:: law

    :code:`C = 4 * pi * epsilon * r_in * r_out / (r_out - r_in)`


    Latex:
        .. math::
            C = \frac{4 \pi \varepsilon r_\text{in} r_\text{out}}{r_\text{out} - r_\text{in}}