Electromagnetic induction in a rotating sphere

Abstract

Abstract An account is given of the induction of electric currents in a rotating conducting sphere surrounded by a stationary conducting shell. Both induction by a constant field and the freely decaying modes are treated. The associated mechanical couples are discussed. The results of most interest are those concerning the toroidal magnetic fields. These fields are entirely confined to the interior of the conductor and may play an important part in terrestrial magnetism. Induction in an oscillating sphere is briefly discussed.