Enthalpy change via entropy change and electric field change
============================================================

The infinitesimal change in entropy of the system with a dielectric medium can
be expressed using the change in its entropy and the change in the electric
field strength.

**Conditions:**

#. The dielectric is isotropic whether or not the electric field is present.
#. The medium is homogeneous.
#. The volume change of the medium is insignificant.

**Links:**

#. Formula 31.9 on p. 122 of "General Course of Physics" (Obschiy kurs fiziki), vol. 3 by Sivukhin D.V. (1979).

.. py:currentmodule:: symplyphysics.laws.thermodynamics.dielectrics.enthalpy_change_via_entropy_change_and_electric_field_change

.. py:data:: enthalpy_density_change

    Infinitesimal change in :attr:`~symplyphysics.symbols.thermodynamics.enthalpy` of the system per unit :attr:`~symplyphysics.symbols.classical_mechanics.volume`.

Symbol:
    :code:`dH`

Latex:
    :math:`dH`

Dimension:
    :code:`energy/volume`


.. py:data:: temperature

    :attr:`~symplyphysics.symbols.thermodynamics.temperature` of the system.

Symbol:
    :code:`T`

Latex:
    :math:`T`

Dimension:
    :code:`temperature`


.. py:data:: entropy_density_change

    Infinitesimal change in :attr:`~symplyphysics.symbols.thermodynamics.entropy` of the system per unit :attr:`~symplyphysics.symbols.classical_mechanics.volume`.

Symbol:
    :code:`dS`

Latex:
    :math:`dS`

Dimension:
    :code:`energy/(temperature*volume)`


.. py:data:: electric_displacement

    :attr:`~symplyphysics.symbols.electrodynamics.electric_displacement`.

Symbol:
    :code:`D`

Latex:
    :math:`D`

Dimension:
    :code:`charge/area`


.. py:data:: electric_field_change

    Infinitesimal change in :attr:`~symplyphysics.symbols.electrodynamics.electric_field_strength`.

Symbol:
    :code:`dE`

Latex:
    :math:`dE`

Dimension:
    :code:`voltage/length`


.. py:data:: law

    :code:`dH = T * dS - D * dE`


    Latex:
        .. math::
            dH = T dS - D dE