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ampere

(Encyclopedia)ampere ămˈpēr [key], abbr. amp or A, basic unit of electric current. It is the fundamental electrical unit used with the mks system of units of the metric system. The ampere is officially defined a...

Galvani, Luigi

(Encyclopedia)Galvani, Luigi lo͞oēˈjē gälväˈnē [key], 1737–98, Italian physician. He was professor of anatomy from 1775 at the Univ. of Bologna and was noted as a surgeon and for research in comparative a...

Volta, Alessandro, Conte

(Encyclopedia)Volta, Alessandro, Conte älĕs-sänˈdrō kônˈtā vôlˈtä [key], 1745–1827, Italian physicist. He was professor of physics at the Univ. of Pavia from 1779 and became famous for his work in elec...

voltaic cell

(Encyclopedia)voltaic cell, a simple device with which chemical energy is converted into electrical energy. Two dissimilar metals (e.g., copper and zinc) are immersed in an electrolyte (e.g., a dissolved sulfate). ...

tachometer

(Encyclopedia)tachometer tăkŏmˈətər [key], instrument that indicates the speed, usually in revolutions per minute, at which an engine shaft is rotating. Some tachometers, especially those used in automobiles, ...

Stark, Johannes

(Encyclopedia)Stark, Johannes, 1874–1957, German physicist, Ph.D. Univ. of Munich, 1897. From 1900 until he retired in 1922, Stark served short stints on the faculties of several academic institutions, including ...

Van Halen, Eddie

(Encyclopedia)Van Halen, Eddie (Edward Lodewijk Van Halen), 1955–2020, American rock musician and song writer, b. Amsterdam, Netherlands; his family moved to California when he was young. He and brother Alex form...

silicon carbide

(Encyclopedia)silicon carbide, chemical compound, SiC, that forms extremely hard, dark, iridescent crystals that are insoluble in water and other common solvents. Widely used as an abrasive, it is marketed under su...

Sioux City

(Encyclopedia)Sioux City, city (1990 pop. 80,505), seat of Woodbury co., NW Iowa, at the junction of the Big Sioux and Floyd rivers with the Missouri; inc. 1857. It is a shipping, wholesale trade, and industrial ce...

Siemens, Sir William

(Encyclopedia)Siemens, Sir William, 1823–83, English electrical engineer, b. Germany; brother of Ernst Werner von Siemens. Originally his name was Carl Wilhelm Siemens. After visiting England to introduce an elec...