Current is voltage over impedance
=================================

Alternating current flowing through an electric component is proportional to voltage applied to it
and inversely proportional to its impedance. This is the complex generalization of the :ref:`Ohm's
law <Current is voltage over resistance>`.

**Notes:**

#. This is a phenomenological equation.

**Conditions:**

#. The material must be ohmic, i.e. current must be proportional to voltage.

#. The AC circuit must be time-invariant.

**Links:**

#. `Wikipedia — Ohm's law <https://en.wikipedia.org/wiki/Ohm%27s_law#Reactive_circuits_with_time-varying_signals>`__.

#. `Univeristy of Maryland — Complex impedance method for AC circuits <https://physics.umd.edu/~jacobson/273c/impedance.pdf>`__.

.. py:currentmodule:: symplyphysics.laws.electricity.current_is_voltage_over_impedance

.. py:data:: current

    Phasor :attr:`~symplyphysics.symbols.electrodynamics.current` through the component.

Symbol:
    :code:`I`

Latex:
    :math:`I`

Dimension:
    :code:`current`


.. py:data:: voltage

    Phasor :attr:`~symplyphysics.symbols.electrodynamics.voltage` across the component.

Symbol:
    :code:`V`

Latex:
    :math:`V`

Dimension:
    :code:`voltage`


.. py:data:: impedance

    :attr:`~symplyphysics.symbols.electrodynamics.electrical_impedance` of the component.

Symbol:
    :code:`Z`

Latex:
    :math:`Z`

Dimension:
    :code:`impedance`


.. py:data:: law

    :code:`I = V / Z`


    Latex:
        .. math::
            I = \frac{V}{Z}