Researchers think it's the effect of convection currents in our planet's molten interior that causes the entire Earth to behave as one gigantic magnet, with a North and South Pole.
研究者们认为，是地球内部熔岩里对流流的作用使得整个地球像个拥有南北磁极的巨型磁体一样运转。
2
Permanent magnet Deferrizater iron is a complicated process, in addition to iron around the iron was magnetized iron removal effect will be affected.
永磁除铁器除铁是一个复杂的物理过程，除铁器周围铁件被磁化后除铁效果会受影响。
3
The inverse effect also occurs: a spinning bar magnet will cause a suspended copper disk to rotate.