talkmagic.co.uk

It's not entirely magic related, and there's a swearword at the end (so maybe NSFW), but today's Abstruse Goose cartoon is a pretty good explanation of how magnets work. http://abstrusegoose.com/

Thanks Tomo.

Soooo, passing a current through a wire and then coiling the wire creates a solenoid. Which increases the magnetic field quite a bit. Is this why you aren't supposed to wind or coil electric cables when they are in use?

Wishmaster wrote:Thanks Tomo.

Soooo, passing a current through a wire and then coiling the wire creates a solenoid. Which increases the magnetic field quite a bit. Is this why you aren't supposed to wind or coil electric cables when they are in use?

I think it was safety advice, really. When you pass a current through a wire it heats slightly due to it's natural resistance. If you put a lot of wire in one place, all that heat is also in one place. I've never heard of a domestic extension coil getting so hot it burst into flames, but I don't know everything.

The interesting thing is that if you place an iron bar inside the coil, it focuses and concentrates the field. I was talking to a friend on Monday night who's a magnet specialist about what would happen if that core was neodymium instead of iron or steel. He had no idea but was interested in finding out what the result would be. Time to break out the magnets, methinks!

And the goggles...

Mr_Grue wrote:And the goggles...

Brass ones, naturally... and black rubber acid gauntlets!

We'll come and visit you in hospital Tomo.

Will it create a super strong field or do something else? Does the field size increase with strength or is that constant? You've started something now you know. Lots of questions here.

Wishmaster wrote:We'll come and visit you in hospital Tomo.

Will it create a super strong field or do something else? Does the field size increase with strength or is that constant? You've started something now you know. Lots of questions here.

Well, the more energy in the form of electricity you throw at the coil, and the more coil you have, determines the strength of the field. My magner-bothering friend thought that maybe because the domains in a permanent magnet are already aligned, a long neo would do nothing to concentrate or "turbo charge" the resulting field. I'll know next week. Next week is R&D week. Me like R&D week. Me like a lot!

My guess involves black holes and the end of the world

I'll be interested to see the results of this, but if I were to hazard a guess I would say that the neodinium would not increase an electromagnet's magnetism. It might stick to it though.

Still, I don't really know squat about magnets other than what I remember from science classes at school and that if you have a certain magical magnetic device (you know the one) and you drop it onto a stone floor, it breaks in half quite cleanly. Neodinium is more fragile than I thought >: