# Magnet Ball for iPhone Do it Yourself

Magnetic energy and electric energy are related by Maxwell's equations. The potential energy of a magnet of magnetic moment m in a magnetic field B is defined as the mechanical work of magnetic force (actually of magnetic torque) on re-alignment of the vector of the magnetic dipole moment, and is equal:

E_{\rm p,m} = -m\cdot B

while the energy stored in an inductor (of inductance L) when current I is passing via it is

E_{\rm p,m} = {1\over 2}LI^2.

This second expression forms the basis for superconducting magnetic energy storage.

Energy is also stored in a magnetic field. The energy per unit volume in a region of space of permeability \mu containing magnetic field B is:

u={1\over 2}{B^2 \over \mu}

If the magnetic field is an area in the x,y directions, then 3D fundamental magnoflux energy may be formed by applying a voltage at right angles in the z direction.

*Magnet Ball for iPhone Do it Yourself*E_{\rm p,m} = -m\cdot B

while the energy stored in an inductor (of inductance L) when current I is passing via it is

E_{\rm p,m} = {1\over 2}LI^2.

This second expression forms the basis for superconducting magnetic energy storage.

Energy is also stored in a magnetic field. The energy per unit volume in a region of space of permeability \mu containing magnetic field B is:

u={1\over 2}{B^2 \over \mu}

If the magnetic field is an area in the x,y directions, then 3D fundamental magnoflux energy may be formed by applying a voltage at right angles in the z direction.

*From Wikipedia, the free encyclopedia*