We went to Under Saddle Yoke near Moffat to find another marmot. We had to cross an electric fence below Saddle Yoke. Mrs B suggested testing the electric field with a compass. I was unable to get a shock from the wire but companions attested to the fact that it was live. The photo below shows the compass held a decent distance above the wire. It points correctly north and south.
Held close above the wire, it lines up with the wire.
Same when held close below the wire.
Maxwell's Right Hand Grip Rule would suggest that the compass should be perpendicular to the wire and in opposite directions above as below. The lining up with the wire could be that the wire is ferro-magnetic and has induced magnetism from the compass, thus becoming an opposite poled magnet itself and attracting the needle.
