how do magnets attract things like iron from a distance, without using energy?

Question

I’ve read somewhere that magnets dont do work so they dont use energy, but then how come they can move metallic objects? where is that coming from?

In: Physics

Answer 1

They do. Magnetic fields produced by finite loops of current don’t do work. Intrinsecal magnetic fields (electron spin) do. The saying “magnetic fields do no work” comes from the fact classical electrodynamics doesn’t contemplate spin.
For a long rant about the same thing, check [this video](https://youtu.be/fHG7qVNvR7w)