Electrode access to specific interior conduction paths in a low-Rm ferrite cylindrical shell

Determine whether attaching external electrodes to a magnetically permeable, electrically conducting cylindrical shell (with inner radius a > 0, outer radius b, and long axis orthogonal to both Earth's axisymmetric geomagnetic field and the local rotational velocity) can select or access a specific interior conduction path for which the electromotive force is nonzero, rather than yielding only an averaged response over many interior paths due to current distribution in the homogeneous conductor.

Background

The theoretical analysis identifies closed paths within a magnetically permeable conducting cylindrical shell (with low magnetic Reynolds number Rm < 1 and topology satisfying ∇×(v×B) ≠ 0) along which a nonzero electromotive force should arise when the shell corotates with Earth through its axisymmetric geomagnetic field.

However, in practical measurements the shell is a continuous homogeneous conductor, raising uncertainty about whether external electrode placement can isolate a single interior path versus sampling an aggregate of many paths. The experiments treat the shell as a lumped element by attaching multimeter leads to the ends, sidestepping the unresolved issue of path selectivity.