# ampere

## noun

am·​pere ˈam-ˌpir
also
-ˌper
plural amperes
1
: the practical meter-kilogram-second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm
2
: the base unit of electric current in the International System of Units that is defined by setting the fixed numerical value of the elementary charge to 1.602176634 x 10-19 ampere seconds

## Examples of ampere in a Sentence

a current of 15 amperes
Recent Examples on the Web The rate of flow is measured in amperes: 1 amp = 6.24 x 1018 electrons flowing through a certain point per second. Rhett Allain, WIRED, 23 Feb. 2024 The unit of electric current known as the ampere, or amp for short, is named after the founder of electrodynamics. IEEE Spectrum, 11 July 2023 The digital circuit breaker is also about 3,000 times as fast as most mechanical breakers, enabling circuit interruption capabilities up to 150,000 amperes, the upper limit for today’s circuit breakers. IEEE Spectrum, 20 June 2023 But Mudawar, who has previously collaborated with Ford Motor Co., is developing a system that would use special cooling technology to get more than 2,400 amperes—1,400 amperes of current would put five-minute EV charging within reach. Rebecca Heilweil, Smithsonian Magazine, 24 May 2023 Right now, researchers think that faster-charging EVs would need charging cables that can handle far more amperes—the unit for electric current—than what vehicles can handle today. Rebecca Heilweil, Smithsonian Magazine, 24 May 2023 Despite its size, the KiloDrone draws just 1.2 amperes at 12 volts. IEEE Spectrum, 21 Sep. 2020 Projections from the research firm Omdia for 1,200-V SiC MOSFETs indicate a price of 16 cents per ampere in 2025. IEEE Spectrum, 26 Mar. 2023 These are: the meter, the kilogram, the ampere, the candela, the mole, the kelvin, and the second. Tom Vanderbilt, Harper’s Magazine , 13 Mar. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ampere.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

## Word History

Etymology

André-Marie Ampère

First Known Use

1881, in the meaning defined at sense 1

Time Traveler
The first known use of ampere was in 1881

ampere

Ampère

## Cite this Entry

“Ampere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ampere. Accessed 2 Mar. 2024.

## Kids Definition

ampere

noun
am·​pere
: a unit for measuring the rate of flow of an electric current

## Medical Definition

ampere

noun
am·​pere
ˈam-ˌpi(ə)r also -ˌpe(ə)r
1
: the practical mks unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm
2
: the base unit of electric current in the International System of Units that is equal to a constant current which when maintained in two straight parallel conductors of infinite length and negligible circular sections one meter apart in a vacuum produces between the conductors a force equal to 2 × 10−7 newton per meter of length

Ampère

## biographical name

Am·​père
André-Marie 1775–1836 French physicist

## More from Merriam-Webster on ampere

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!