Wikipedia:Reference desk/Archives/Science/2018 June 23

= June 23 =

Where is the south pole of a power meter's north pole?
I've read that a magnetic monopole has never been observed. In Toronto in the early 2000s, I used a magnetic compass for some science-class work and noticed that when close enough to a power meter, it would always mark the meter as the magnetic north pole. (My neighborhood was of older semidetached houses; I was told my home at the time had been built in the 1950s.) Where is the south pole of a magnet, whose north pole is a power meter of the type I would have observed? Neon Merlin  03:31, 23 June 2018 (UTC)
 * If I understand your question properly, the "north pole" would be the compass needle's attraction to the meter's electromagnetic field (EMF) -- and in effect, the "south pole" would be, in this case, "ground". 2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 07:09, 23 June 2018 (UTC)
 * No. The compass needle aligns itself along a Field line that emerges from a south magnetic pole and curves through space to return to a north magnetic pole. Both these magnetic poles are located inside the electric power meter and produce an external Magnetic field. This could be prevented by shielding the meter with an iron case. DroneB (talk) 11:40, 23 June 2018 (UTC)