Force on Dipoles and Hidden Momentum

摘要

After a brief review of "hidden momentum" and the various approximate methods and arguments that have been used for determining the force on Amperian electric and magnetic dipoles, we rigorously solve Maxwell's equations for the force on electrically small perfect electric conductors (PEC's) carrying electric and magnetic dipoles induced by external fields to prove unequivocally that there is an internal ("hidden-momentum") force exerted on the charge-current of the PEC by internal fields in the PEC induced by the external fields - thereby making the force on the Amperian magnetic dipole equal to the force on a magnetic-charge magnetic dipole with the same magnetic dipole moment in the same external field.