What is this?

[Caryc]

LARGE electric motors typically contain zero permanent magnets. They are mostly like induction motors and generate magnetic fields through electromagnetic induction instead.electromagnets.

There are some permanent magnet motors, but most are induction.

I once bought a big bass speaker for my car. It had a five pound magnet in it.

 

[Tony in SD]

I once bought a big bass speaker for my car. It had a five pound magnet in it.

Interesting how most motors are induction and most speakers have permanent magnets now days. However back in the day 100 years ago or so, the speakers of large cabinet radio used DC voltage to induce a magnetic field for the audio speaker coil to react against to produce sound..