How to Make a Temporary Magnet

Video Transcript

"Hi, I'm Steve Jones, and I'm going to tell you how to make a temporary magnet. It's an interesting word to use for a magnet, temporary, because in fact, most magnets are either permanent, that is they're always magnetic, or they're electromagnets, which are magnetic when you switch them on, and they're not magnetic when you switch them off, so a temporary magnet is really more like an electromagnet. You can't have a permanent magnet, which is temporary. It won't be permanent if it's temporary. You can have weaker magnets, or stronger magnets, or magnets that lose their magnetism, but then they wouldn't be called permanent magnets, so let's look at the kind of magnets here, that we're talking about, a temporary magnet. An electromagnet, basically, we know that we usually start with a core of iron, or something of that kind, and around the iron, we would wrap a coil of wire, and that coil of wire would then be attached to a battery, and that makes our electromagnet. The electromagnet is temporary, because when you switch on the current, the magnet becomes magnetic, and when you switch the current off, the iron, because of the nature, we call it soft iron. Soft, meaning it loses its magnetism, so when we switch off the current, this becomes de-magnitized, so this is a true temporary magnet. It's not a permanent magnet. It's only magnetic, when you've got the current flowing through it. Now, you can make permanent magnets, weaker permanent magnets, and obviously, permanent magnets are used in things like electric motors, because you don't want the magnetism to disappear, from the electric motor, but something like an electromagnet, a temporary magnet, might be used to lift iron or steel, in a scrapyard, for example, so this is where the temporary magnet, or electromagnet, is useful, because if I want to pick up a piece of steel, I pick it up, but it's no good, if it then sticks to the machine, that I've picked it up with. I have to be able to de-magnetize it, and drop it somewhere else, and that's why this temporary magnet is important, so that's how I make a temporary magnet."