A method for controlling an electric machine includes measuring a motor control parameter or parameters and selectively positioning an adjustable member within the electric machine in response the motor control parameters. Selective positioning of the adjustable member varies the geometry of a flux path within the electric machine, thereby inducing a predetermined voltage output in the electric machine. An electric machine includes a rotor, a shaft operatively connected to the rotor to rotate in conjunction therewith, and a stator. An adjustable member is positioned between the rotor and the stator, and has a variable offset position that can be selected by an electronic control unit (ECU) and applied by an actuator to thereby vary the geometry of a flux path within the electric machine. The adjustable member can include a non-magnetic annular hub and magnetic radial arms and axial extensions.