Is the ring magnetised?

The weblink is to a Nuffield Foundation suggested practical; you have to heat treat thin metal washers (so that they can be snapped easily) and then magnetise them (circularly) by passing 100Amp (suggested) through a wire passed through the middle of the washer. This could prove problematic; if you follow the advice to thread the wire through again and again, make sure the wire is threaded through the same direction each time to avoid cancelling out the field! The word document is just a printable version of the website. A prac to try out for yourself first!