As is known, a toroid magnet is generally doughnut shaped with {HEAD ~ a hole} in {TAIL ~ the middle}; one side is north, the other south 
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As is known , a toroid magnet is generally doughnut shaped with { HEAD ~ a hole } in { TAIL ~ the middle } ; one side is north , the other south
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH