Physics/Magnetizing a metal object with a magnet
I have been playing around with magnets, and noticed that a magnet attracting a nail will cause that nail to also attract another nail. I do not know what the technical term for this magnetic transfer is, but I would like to ask a question about this phenomenon.
I have read that an electric current produces a magnetic field, so I am wondering what would happen if you had a copper wire connected to a permanent magnet at one end, and a ferrous metal object at another. Would running current through the copper wire cause the ferrous metal object to become magnetized by the permanent magnet in the same way that my nail was magnetized?
Some things to know:
1) Ferrous material, by definition, is any material that strengthens the magnetic field (scientists call it the 'B-field') placed on it. It doesn't matter WHERE that external B-field comes from; if you place ferrous material within a B-field, that B-field will be strengthened by the presence of the ferrous material.
2) The B-field created by a current AND the B-field created by a permanent magnet are identical. For a ferrous material, it doesn't matter whether the external B-field is from either of these sources, the ferrous material will increase the strength of the B-field coming from outside it.
Thus, your question is a little ambiguous. If you have ferrous material near a permanent magnet, the B-field from the permanent magnet will be stronger. Same thing for a B-field coming from a current. Thus, in BOTH cases, the ferrous material MIGHT increase the B-field coming from outside to the point where the ferrous material acts like a permanent magnet. Or, in both cases, it might not. It all depends on how strong is the B-field coming from outside the ferrous material.
As you noted, when you moved your permanent magnetic close to the ferrous material, the B-field from your permanent magnet did become strong enough to make the ferrous material act like another permanent magnet. Whether trying to do the same with current will work is impossible to say.