31. There is an ideal n ?n ?n lattice of aligned magnetic dipoles , d units apart. 32. So the most basic entity, corresponding to a point electric charge, is a point magnetic dipole . 33. In the physically correct Amp�re model, magnetic dipole moments are due to infinitesimally small loops of current. 34. Likewise, the electric field from a magnetic dipole behaves like the magnetic field from an electric dipole. 35. Following is the formula for moving charge; for the forces on an intrinsic dipole, see magnetic dipole . 36. The magnetization field of a region points in the direction of the average magnetic dipole moment in that region. 37. Unfortunately, the small magnitudes of nuclear magnetic dipoles also makes them less inclined to align to external fields. 38. A changing external magnetic field causes the magnetic dipoles to rotate, changing the dimensions of the crystal lattice. 39. In paramagnetic materials, the magnetic dipole moments of individual atoms spontaneously align with an externally applied magnetic field. 40. That means the magnetic field from a magnetic dipole behaves similarly to the electric field from an electric dipole.
