How to Create an Electromagnet

Video Transcript

"Hi, I'm Steve Jones and I'm going to show you how to create an electromagnet. Now the first thing that you are going to need is a coil of copper wire. This is insulated copper wire. The importance of the copper, don't have to be copper, but it's best copper. Other good conductors are things like gold and silver, which are too expensive, and aluminum, which is a little bit brittle. So this should be copper wire, and it should be insulated on the outside, either by lacquer, or by plastic. So you have a piece of copper wire. You need a cardboard tube of some kind. And you simply wrap the copper wire around the cardboard tube until you've got a coil like this, with one end at each end. Bare the ends, attach it to a battery, and you have an electromagnet. Just be careful, though. Make sure the wire is long enough to give enough resistance so the current isn't too great. To make it much stronger, we always put a core inside. The core should be iron, and normally is laminated, but it doesn't actually have to be with this type of magnet. And we take the core and we simply put it inside the tube, and that will increase the strength of the electromagnet by a factor of ten or so. It's a very effective way of increasing the strength. Sometimes we'll find that the best kind of magnet is one like this, a horseshoe, where you wrap the coil around. Essentially you can wrap it right the way 'round, and this end will be a north pole, and this end a south pole. That means that if you put a piece of metal, iron, across the top, you'll get a very, very strong attraction between that iron and this coil. You'll get what's called a magnetic circuit, and this is a very effective way of making an electromagnet. The magnet is very strong. You don't lose any of the magnetism. It is channeled through this iron in here. So that is basically how to create an electromagnet."