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# Magnetic Shielding Watch

1. Hi, please could someone explain the following experiment. You tie a paper clip to a piece of string fixed to a clamp stand and then use a magnet to make it hover in mid air. You then swipe different materials between the magnet and the paperclip. Some materials make it fall and other have no effect. Magnetic materials (e.g. steel) seem to have an effect. Please could someone explain how this works. From what I have read I have an idea. I know it has something to do with magnetic shielding. Say if you put another paper clip in-between the magnet and the levitating paperclip on the string then will the paperclip in the middle essentially provide a place for magnetic field lines form the magnet to terminate leaving less to terminate on the levitating clip and hence it falls? But I thought magnetic materials strengthened the field though (as in an electromagnet) so shouldn't the magnetic material make the attraction to the levitating clip stronger?
2. (Original post by Bibloski)
Hi, please could someone explain the following experiment. You tie a paper clip to a piece of string fixed to a clamp stand and then use a magnet to make it hover in mid air. You then swipe different materials between the magnet and the paperclip. Some materials make it fall and other have no effect. Magnetic materials (e.g. steel) seem to have an effect. Please could someone explain how this works. From what I have read I have an idea. I know it has something to do with magnetic shielding. Say if you put another paper clip in-between the magnet and the levitating paperclip on the string then will the paperclip in the middle essentially provide a place for magnetic field lines form the magnet to terminate leaving less to terminate on the levitating clip and hence it falls? But I thought magnetic materials strengthened the field though (as in an electromagnet) so shouldn't the magnetic material make the attraction to the levitating clip stronger?
I suspect your magnet is positioned such that the N or S pole is nearest the clip and shield.
However the principle is the same.

http://www.kjmagnetics.com/blog.asp?...ding-materials

Yes the steel does "strengthen" the field but it concentrates the lines of flux within itself, preventing them from getting out the other side. This reduces the field strength on the other side of the plate.

This also shows it but not so clearly.

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Updated: January 23, 2015
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