Apparatus (200) for use as a motor or generator, comprising: a first part (210); a second part (230) movable relative to the first part (210) and spaced from the first part (210) by an air gap (260); and a plurality of spaced activatable magnet elements (220) provided on the first part (210), each activatable magnet element (220) being operative when activated by application of an electric current thereto to direct a magnetic field across the air gap (260) towards the second part (230); wherein each activatable magnet element (220) comprises: a pole piece (222) defining an air-gap facing surface (223A, 223B), the pole piece (222) comprising: a first limb (224A); a second limb (224B); and a coil-winding section (224C) positioned between the first and second limbs (224A, 224B); a permanent magnet arrangement (225) provided between the first and second limbs 224A, 224B) of the pole piece; and an electrically conductive coil (226) wound around the coil-winding section (224C) of the pole piece, wherein the electrically conductive coil (226) is operative to generate a magnetic flux oriented to oppose the magnetic flux of the permanent magnet arrangement (225); characterised in that the pole piece (222) further comprises a parallel flux path section (224D) extending in parallel to the coil-winding section (224C) operative to allow magnetic flux from the permanent magnet arrangement (225) to flow in parallel to the coil-winding section (224C).