Named after the French physicist André-Marie Ampère, it is one of the seven base units in the International System of Units (SI), used to measure electric current. It is universally adopted, especially in scientific and engineering fields. One ampere represents a charge flow of one coulomb per second through a conductor's cross-section.

A unit of electric current where 1 milliampere equals 0.001 amperes. Commonly used for electronic device operating currents (e.g., an LED draws ~20 mA), sensor signals (4–20 mA industrial standard), and battery capacity estimation. Universally adopted in electronics and automation industries in China and globally.