The ampere (A) is the SI unit of electric current. It is defined as the constant current that, when maintained in two straight parallel conductors of infinite length and negligible circular cross-section, produces a force of 2 × 10^-7 newtons per meter between them.
The term "ampere" is named after André-Marie Ampère, a French physicist, who contributed significantly to the study of electromagnetism in the early 19th century. The ampere was standardized in the late 1800s, and its definition was refined during the International System of Units (SI) establishment in 1960.
Amperes are widely used in electrical engineering, electronics, and physics to measure current flow. Common applications include household electrical systems, electronic devices, and power generation. Most countries use the ampere as the standard unit for electrical measurements.