Analysis of electrical machinery is usually carried out with the aid o
f lumped-parameter techniques; at the same time, a distributed-paramet
er model is of theoretical interest, as it, provides insight into the
behavior of the magneto-electric device without any restriction impose
d upon supply frequency, with of air gap or even velocity. An analysis
which takes into account the finite velocity c of a plant: electromag
netic wave in vacuum, of necessity resorts to restrict,ed relativity,
which has the great advantage of leaving the field equations form-inva
riant. In the present paper such an approach is briefly outlined.