Questions about magnets.

[jdiwnab]

Originally Posted by Elgin Clock

What is the strongest pole?

Neither is stronger. The strength of a magnet is based on the material, the size and somewhat the age. If you took a bar magnet and a Guassmeter (measures magnetic field intensity. 10,000 Gauss=1 Tesla=very strong magnet. 500 is fairly strong), you will see that the N end will have approx the same value as the S end (but one will be negative). Around the middle, you will have nearly 0. The sensor I was using for a science project regularly read about -1.7 Gauss (I guess Earth's magnetic field) and went up to about -+ 100 gauss with the really weak, old magnets the school had.

If you can find an old microwave, then you could find some very strong ring magnets in the "MAGNETRON" (that is really what they are called). I measured one and was getting about -+800 gauss

[sanddrag]

You can get really strong magnets out of hard drives. I would recommend using old broken ones as working hard drives are expensive.

[Joe Ross]

Try here for strong magnets: http://search-desc.ebay.com/Neodymiu...Z2QQsacatZ1266

[jgannon]

Originally Posted by Joe Ross

Try here for strong magnets: http://search-desc.ebay.com/Neodymiu...Z2QQsacatZ1266

I second that. Neodymium magnets are as strong as they get, and eBay is always a fantastic place for good deals.

[Kevin Sevcik]

*rubs hands together* Boy are you in for it....

http://www.amazingmagnets.com
http://www.engconcepts.net/
http://www.wondermagnet.com
The last one also has ferro-fluid.

Also, in response to to one pole of a magnet being "stronger" than another... If a magnet is symmetrical on a plane perpendicular to the poles, then they're the same strength. You can increase the surface gauss at one end by tapering it to a point, however. It doesn't matter if this end is a N or S pole, however.

For lots of info on magnets and stuff, see:
http://www.dansdata.com/magnets.htm
http://www.dansdata.com/magnets2.htm

[sanddrag]

Originally Posted by Kevin Sevcik

http://www.wondermagnet.com
The last one also has ferro-fluid.

That stuff is really cool. I saw on TV something sort of like that which they were developing to use as fluid in off-road racing shocks to essentially change the viscosity in a matter of miliseconds.

[JoeXIII'007]

You can make an electromagnet with some sort of magnetically attractable metal core and a coil of wire plus an electric current to boot. They're usually weaker though. For some really strong magnets, look in any bad trashed audio speaker (not internal to a TV set).

Oh yeah, they do have N&S poles as others have mentioned, when split in two they indeed make two separate magnets. There is no such thing as the strongest pole and the best shielding is space or some seriously magnetic resistant material. I could not name one for you though.

-Joe