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Volume 15: Pages 371-378, 2002
Ampère Force Without Ampère's Disproved Third Law
Robert B. Driscoll
Istituto per la Ricerca di Base
The Marinov motor disproves Ampère's third law (that the ponderomotive force exerted on a current element by a closed circuit is always normal to the direction of the current element). Consequently, the conventional Ampère force law and the Lorentz force are invalid. However, the other three force laws of Ampère result in the corrected Ampère force IiIjr−2[a(dsi dsj) + b(rˆ dsi)(rˆ dsj) + crˆ (dsi × dsj)]rˆ, where a, b, and c are constants, rˆ = r/r, and r extends from dsi to dsj. The invalid conventional Ampère force is derived from this valid force and the now disproved third law. The corrected force, applied to two separated infinite rectilinear circuits when parallel and when at right angles, from the known currents and separations and the measured forces, gives b = −3(a − 1), c = 0. A special Marinov motor is designed to facilitate analysis. It is shown that a coplanar circular closed circuit, centered on the radius between the center of the ring (rotor) and one of the brush points, exerts a finite torque on the ring about its axis of axial symmetry. Technological elaborations are briefly indicated.
Keywords: Ampère force, Lorentz force, Marinov motor
Received: October 7, 1999; Published online: December 15, 2008