Equivalence Principles and Electromagnetism

The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, I show that the universality of free-fall trajectories {Galileo weak equivalence principle (WEP[I])} does not imply the validity of the Einstein equivalence principle (EEP). However, WEP[I] plus the universality of free-fall rotation states (WEP[II]) does imply EEP. To test WEP[II] and EEP, I suggest that E\"otv\"os-type experiments on polarized bodies be performed.