refrigerator magnets

[dstebbins]

Refrigerator magnets stick to refrigerator doors (duh, common sense, eh?), so the fridge must have an opposite magnetic charge to a fridge magnet. One is positive, the other is negative.

 

But by that notion, two fridge magnets should both be the same charge, and thus should repel each other, yet they stick to each other. Why is that?

 

EDIT: Btw, I put this in Chemistry because I learned about positive and negative charges in Chemistry class. If this is in the wrong board, please quietly move it to the proper one.

[Cap'n Refsmmat]

You're talking about electrostatic charges, like you get with static electricity (where your hair raises up). Magnetism is somewhat different.

 

http://en.wikipedia.org/wiki/Magnetism

[Phi for All]

Refrigerator magnets are made with alternating positive and negative poles on their surface so they'll stick better. If you place two flat fridge magnets together and rub them against each other you can feel the attraction and repulsion.

 

The surface of the fridge is not a magnet, it's just made from a ferrous metal.

 

I used to work with some guys in AZ who made and sold custom fridge magnets. The sheet material doesn't come pre-charged. You print the sheet, die cut it in the shape required, then box it up to ship to the client. Before shipping you run the order through a magnetizer as the last step, otherwise they'd be sticking to your machinery all the time.

[Pangloss]

That sounds like an interesting machine. Any idea how it did its thing?

[swansont]

The surface of the fridge is not a magnet, it's just made from a ferrous metal.

 

Meaning that it has magnetic domains that can align in response to an external field, so it becomes magnetic. And attraction lowers the energy for this type of material.

[Klaynos]

That sounds like an interesting machine. Any idea how it did its thing?

 

Big electromagnet?

[dstebbins]

You're talking about electrostatic charges, like you get with static electricity (where your hair raises up). Magnetism is somewhat different.

 

http://en.wikipedia.org/wiki/Magnetism

 

But aren't electricity and magentism essentially the same thing?

[swansont]

But aren't electricity and magentism essentially the same thing?

 

They are related, but not the same.

[Phi for All]

That sounds like an interesting machine. Any idea how it did its thing?

Big electromagnet?

I worked remotely with those guys so I never saw their setup but I think their magnetizer is just a big electromagnet that creates a field through which the magnet orders were passed. IIRC, the longer the magnets stayed in the magnetizer the stronger they were. Fridge magnets don't need much (most of the promotional mags on my fridge won't hold more than two sheets of paper).

[Mr Skeptic]

That sounds like an interesting machine. Any idea how it did its thing?

 

Any constant magnetic field will eventually magnetize iron. If you heat the iron up a lot, and let it cool in a magnetic field, it will magnetize very quickly.

[spikegomez]

Magnetism and electricity is not the same but it's exactly related,

Magnets have two polls the north and the south, and electricity has positive and negative particles. how ever, the electricity can be convert to magnet and magnet can be convert to electricity... that is how the magnet and electricity are said to be similar.

The refrigerator wall is not exactly a magnet but it is a commonly metal, that can attract magnets... the refrigerator magnets are have an alternating polls so when we put the two magnets(Refrigerator magnets) together, they attract each other...

hope this help you a little...

Edited November 22, 2008 by swansont
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