Permanent magnet
part · 600 BC · Ancient world
A material with stable magnetization.
Principles and materials it uses
- Magnetism — uses. A permanent field.
- Lodestone — is made of. The first magnets were pieces of lodestone.
Where it is used
- Compass — is part of. The needle is a magnet.
- Loudspeaker — is part of. A permanent magnet.
- Galvanometer — is part of. A magnet.
- Speedometer — is part of. A rotating magnet drags the needle.
- Headphones — is part of. A magnet moves the diaphragm.
- Pickup — is part of. A magnet magnetizes the string.
- Dynamic microphone — is part of. The coil moves in the field of a magnet.
- Magnetron — is part of. A magnet makes the electrons spiral.
- Subwoofer — is part of. A magnet system moves the cone.
- Electricity meter — is part of. A braking magnet.
History: what it evolved from and what it influenced
- Lodestone — evolved from. The first magnets were lodestone.
What it is a kind of
- Neodymium magnet — includes. A kind of magnet.
Things built in a similar way
- Electromagnet — works like. An electromagnet attracts iron like a permanent magnet, but only while current flows.