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by rlpb
3389 days ago
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A permanent magnet also fights against incoming particles, and doesn't seem to consume any energy. Why would an electromagnet be any different? Edit: the permanent magnet will feel a force applied against it in the opposite direction, of course. In space, that's have to be countered by rockets though, not electrically in the current running through the superconductor, right? |
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Because the incoming electrically charged particle induces current in the coils of the electromagnet.
A permanent magnet does not have to deal with that - even if there is current it doesn't affect the magnetism in a permanent way.
Think about an electric solenoid: A stationary electromagnet does not consume power, a moving one does as it acts on the external magnets.