The performance characteristics of an annular‐arc configuration under the influence of a magnetic field have been experimentally analyzed, particularly with respect to the effects of tensor conductivity andj × Bbody forces. In this device the plasma conditions are such that the electrical conductivity is insufficient to prevent the diffusion of the plasma through the magnetic field, i.e., the magnetic Reynolds number was small. Experiments were conducted with this device using helium and argon at power levels up to 50 kW, magnetic field strengths to 10 000 G, and particle densities of the order of 1016/cm3to 1017/cm3. The electron gyroradius was smaller than the electron mean free path, i.e., &ohgr;e&tgr;e> 1, where &ohgr;eis the gyrofrequency, and &tgr;eis the time between collisions for electrons. The impedance of the arc in helium was found to vary linearly with &ohgr;e&tgr;e. The existence of a circulating azimuthal Hall current was also demonstrated. A yaw probe was employed to measure the angle of the flow due to thej × BLorentz forces. A good agreement was found between the measured rotation in argon and the predicted value obtained from momentum considerations.