1.
electromagnet
A magnet whose magnetic field is produced by passing an electric current through a coil of wire, usually wound around an iron core. Unlike a permanent magnet, its magnetism can be switched on and off and its strength adjusted by changing the current. Widely used in motors, relays, speakers, scrapyard cranes, and maglev trains.
When current is passed through the coil, the iron rod becomes an electromagnet.
Compound of 電磁 ('electromagnetic') and 磁石 ('magnet'), lexically 電(気) + 磁石. The element 磁石 here keeps its independent reading rather than undergoing sequential voicing.
Usage
- A standard topic in elementary and middle school science; the classic experiment is winding a wire around a nail or iron rod, passing current through it, and picking up paper clips.
- Often contrasted with 永久磁石 ('permanent magnet') in physics lessons and textbooks.
- Appears in many everyday contexts as a component: speakers, door locks, relays, MRI machines, particle accelerators.
Common collocations
- 電磁石を作る: to make an electromagnet
- 電磁石の磁力: the magnetic force of an electromagnet
- 電磁石に電流を流す: to pass current through an electromagnet
- 強力な電磁石: a powerful electromagnet
- 電磁石の原理: the principle of the electromagnet
Similar words
- 磁石: magnet — the general term; refers most naturally to permanent magnets.
- 永久磁石: permanent magnet — a magnet that retains its magnetism without a current; the standard contrast to 電磁石.
- 電磁波: electromagnetic wave — related field but refers to waves (light, radio, X-rays), not static fields.
- コイル: coil — the wound wire that produces the magnetic field in an electromagnet.
Related Words
Compare:
永久磁石 (permanent magnet)
Compare:
電磁波 (electromagnetic wave)
Compare:
コイル (coil)