Hi Guys,
Have one of my physics exams tomorrow and i still don't quite get lens's law and eddy currents, anyone have a dummy explanation or a good way of explaining them.
Thanks
Ed

Never heard of it! Are you referring to Flemings right and left hand rules?

These continentals - always pinching our ideas!!

Im talking about:
http://en.wikipedia.org/wiki/Lenz's_law
http://en.wikipedia.org/wiki/Eddy_current

http://micro.magnet.fsu.edu/electromag/java/lenzlaw/

http://micro.magnet.fsu.edu/electromag/java/lenzlaw/

Oh yes got it now.

Thats one of the laws that poo poo's perpetual motion.

If you move a wire in a magnetic field it induces a currene. That very current produces a magnetic field that opposes the motion.

Otherwise you would have no resistance to motion and loads of amps - perpetual motion in other words.

Thats how I remembered it but it was 40 years ago I sat that exam!

http://www.youtube.com/watch?v=bkSsgTQOXVI

Thanks for that video, that helps explain it. So basically it creates another magnetic field to oppose to motion

EDIT: LCB is by far the best source of info for everything!

[Edited on 17/6/10 by eddie99]

Still think you should read up on Flemings rules! Let us know how it goes.

Cheers

Saw the post this morning and looked up and learnt the flemings left hand rule. That came up and i was able to unload my knowledge, unfortunately not one thing came up about Lenz's law and eddy currents but oh well, general knowledge has improved

Sods law I guess.

I used to analyse the cource material and work out what areas it would be difficult to question in a 3 hour exam, what were easy to question and what were key to understanding the subject. Trouble was it was so much work to do this that I studied the whole area to find out and ended up knowing it all (for a short period of time anyhow!!)

Your tutor/lecturer should have guided you on the questions to expect if he/she was worth anythin.

Cheers and enjoy the studying