# Formula Magnetic dipole Magnetic dipole moment Electric current Area

## Magnetic dipole moment

`\( \class{red}{\boldsymbol{\mu}} \)`Unit

`\( \mathrm{A} \, \mathrm{m}^2 \)`

Magnetic dipole moment is a measure of the "strength" of a magnetic dipole. In this case, the dipole moment is generated by a circular current. The \(\class{red}{\boldsymbol{\mu}}\) vector points in the same direction as the surface normal vector.

A torque acts on a magnetic dipole in an external magnetic field, resulting in the orientation of the dipole along the magnetic field direction.

## Electric current

`\( \class{red}{I} \)`Unit

`\( \mathrm{A} \)`

Electric current along a closed loop. For example, a current along a metallic ring.

## Area

`\( \boldsymbol{A} \)`Unit

`\( \mathrm{m}^2 \)`

Area enclosed by a current loop. For a ring current this area is given by: \( A = \pi \, r^2 \), where \( r \) is the radius of the ring. The enclosed area can be associated with an orthogonal vector that is perpendicular to the area. The direction of this vector is determined by the right-hand rule.