Frostbite Theater - Here's a Question!

Here's a Question! - Cut a Magnet

A steel rod is magnetized by swiping it along a permanent magnet. Its field is viewed by placing it under a piece of paper and sprinkling iron filings on it. This shows that it has two poles, one on each end. The rod is then cut in half and the field is viewed again. What is seen?

[ Show Transcript ]

Announcer: Frostbite Theater presents... Cold Cuts! No baloney!

Joanna and Steve: Just science!

Joanna: Hi! I'm Joanna!

Steve: And I'm Steve!

Joanna: Here's a question for you...

Steve: A steel rod is magnetized by swiping it along a permanent magnet. Its field is viewed by placing it under a piece of paper, sprinkling iron filings on the paper, and then shaking the table by smacking a piece of wood with a hammer a number of times.

Joanna: This shows that it has two poles, one on each end.

Steve: The rod is then cut in half and the field is viewed again.

Joanna: What is seen?

Steve: Does one piece have two poles and the other piece have none?

Joanna: Does each piece have two poles?

Steve: Does each piece have one pole?

Joanna: Or, does each piece have no poles?

Pause the video now if you'd like to think it over before we show you what happens.

Joanna: As far as we know, magnetic poles always come in pairs. Magnetic monopoles could exist. They've just never been observed.

Steve: Sadly, cutting a magnet in half doesn't make magnetic monopoles. It just makes two magnets.

Joanna: Thanks for watching. I hope you'll join us again soon for another question!

Citation and linking information

For questions about this page, please contact Carol McKisson.