ampere-turn

ampere-turn — noun

1. a unit used in electrical engineering to measure the magnetic force created when

1.nounC2
Definition

a unit used in electrical engineering to measure the magnetic force created when a single loop of wire carries one ampere of current

Example

In class, Rin calculated that one loop carrying one ampere makes one ampere-turn.

formula idea: one turn x one ampere

The repair guide says this relay needs fifty ampere-turns before the switch closes.

pattern: need + number + ampere-turns

Common collocations
  • produce X ampere-turns
  • need X ampere-turns
  • required ampere-turns
  • coil turns
  • lifting magnet

Grammar Patterns

[number] + ampere-turn(s)

need / produce / create + [number] + ampere-turn(s)

Usage Note

This unit is mostly used in technical writing about coils, relays, and electromagnets. It nearly always appears with a number, and the value rises if you increase either the current or the number of coil turns.

Common Mistakes

The coil produces ten amperes-turn.
The coil produces ten ampere-turns.
In the plural form, add -s to the end of the whole unit, not to 'ampere'.

Word family

  • ampere
    nounB2

Synonym discussion

Sense: noun/1

An ampere-turn is a practical engineering unit for the magnetic force made by current passing through a coil. A gilbert measures the same general idea, but it belongs to an older system and appears mainly in historical or specialist writing. An ampere measures only the electric current in the wire, not the effect of the whole coil. A volt measures electrical pressure, so it answers a different question again. If you double the current or the number of turns, the ampere-turn value also doubles. Use ampere-turn when you want to state how strongly a coil can magnetize something, ampere for current, volt for voltage, and gilbert mostly when reading older material.

gilbert ↗amperevolt

Common collocations

Nouns

Phrases

  • one ampere-turn
  • required ampere-turns
  • produce X ampere-turns
  • need X ampere-turns

Etymology

French surnameEnglish scientific compound

The term combines ampere, the unit named after the French physicist Andre-Marie Ampere, with turn, meaning one loop of wire in a coil. Engineers formed the compound to describe the magnetic force produced by current flowing through a set number of coil turns.