Magnetic pressure

In physics, magnetic pressure is an energy density associated with a magnetic field. In SI units, the energy density ${\displaystyle P_{B}}$ of a magnetic field with strength ${\displaystyle B}$ can be expressed as

${\displaystyle P_{B}={\frac {B^{2}}{2\mu _{0}}}}$

where ${\displaystyle \mu _{0}}$ is the vacuum permeability.

Any magnetic field has an associated magnetic pressure contained by the boundary conditions on the field. It is identical to any other physical pressure except that it is carried by the magnetic field rather than (in the case of a gas) by the kinetic energy of gas molecules. A gradient in field strength causes a force due to the magnetic pressure gradient called the magnetic pressure force.