Cool demonstration of electromagnetic induction using a magnet and copper pipe

Cool. I've seen several demonstrations of eddy-current braking, but this is the best one that doesn't require a big electromagnet.

too.

I have some small Boron Iron magnets about 1/4 in. in diameter that slowly slide down an inclined aluminum cookie sheet. Its a great demo. Of course the same magnets slide very fast down a piece of cardboard to illustrate the difference.

Interestingly these magnets stick to the black specks in our granite counter top. Obviously these specks are some iron mineral in the granite.

You haven't seen jack until you've tried it with a solid silver bar. The thickness makes a lot of difference (more than the 2% conductivity difference ;-), but there's the allure of pure silver too). It takes seconds *per inch*. On an inclined slab, it's so "sticky" the magnet starts tumbling down in slow motion.

Tim

-- Deep Friar: a very philosophical monk. Website:

Tis one's cool too:

I guess one utube leads to another! ;-)

Cheers! Rich