A compact, energy efficient motor having a rotor including N/2 pairs of rotor poles located about the periphery of the rotor, the rotor poles having alternating opposite polarities. The rotor is surrounded by a stator including stator poles concentric to the rotor. The motor is a multiphase motor, each phase including two polar pieces, an internal polar piece and an external polar piece, the polar pieces being interpositioned one within the other. One phase of the motor includes a polar piece having fractional stator poles. A motor constructed according to the invention has no loss of magnetic flux, because the magnetic flux generated by the magnetized rotor poles is always closed upon itself. This increases the efficiency of the motor, and allows high power output with compact size.