Okay, Im not an electrical engineer but I dabble with circuits, electronics, and electromagnets. Id like to know if it is possible to measure the voltage, or current (not sure sure which is applicable here) using the measurement of interaction between one small magnetic field produced, and its influence on a magnetic field of an electromagnet. Not sure if that was clear so Ill restate it. If a wire gives off a magnetic field when energized, could one hold an electromagnet X distance from said wire and the two magnetic fields would interact... Would that interaction of fields lead to finding the wires voltage or current? Simplified: Finding the current/voltage of an unknown wire through its magnetic field.