Magnetic field of coil
======================

Near the center of the coil, the magnetic field is quite uniform and directly
proportional to the current in the coil's wire.

**Notation:**

#. :math:`\mu_0` (:code:`mu_0`) is :attr:`~symplyphysics.quantities.vacuum_permeability`.

**Conditions:**

#. The medium is vacuum.
#. The magnetic field is measured near the center of the coil.

**Links:**

#. `Physics LibreTexts, similar formula 12.7.11 <https://phys.libretexts.org/Bookshelves/University_Physics/University_Physics_(OpenStax)/University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)/12%3A_Sources_of_Magnetic_Fields/12.07%3A_Solenoids_and_Toroids>`__.

.. py:currentmodule:: symplyphysics.laws.electricity.magnetic_field_of_coil

.. py:data:: magnetic_flux_density

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

Symbol:
    :code:`B`

Latex:
    :math:`B`

Dimension:
    :code:`magnetic_density`


.. py:data:: current

    :attr:`~symplyphysics.symbols.electrodynamics.current` flowing through the coil.

Symbol:
    :code:`I`

Latex:
    :math:`I`

Dimension:
    :code:`current`


.. py:data:: length

    :attr:`~symplyphysics.symbols.classical_mechanics.length` of the coil.

Symbol:
    :code:`l`

Latex:
    :math:`l`

Dimension:
    :code:`length`


.. py:data:: coil_turn_count

    Number of turns in the coil. See :attr:`~symplyphysics.symbols.basic.positive_number`.

Symbol:
    :code:`N`

Latex:
    :math:`N`

Dimension:
    :code:`dimensionless`


.. py:data:: law

    :code:`B = mu_0 * I * N / l`


    Latex:
        .. math::
            B = \frac{\mu_0 I N}{l}