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printed circuit

(Encyclopedia)printed circuit, electric circuit in which the conducting paths connecting circuit components are affixed to a flat, insulating base board. The base is typically of plastic, glass, ceramic, or some ot...

Popper-Lynkeus, Josef

(Encyclopedia)Popper-Lynkeus, Josef yōˈzĕf pôpˈər-lünˈkāo͝os [key], 1838–1921, Austrian philosopher, social reformer, and inventor. His unpopular views kept him from any academic position, so he worked ...

transistor

(Encyclopedia)CE5 Simple transistor circuit transistor, three-terminal, solid-state electronic device used for amplification and switching. It is the solid-state analog to the triode electron tube; the transist...

commerce, in economics

(Encyclopedia)commerce, traffic in goods, usually thought of as trade between states or nations. Engaged in by all peoples from the earliest times, it has been carried on in some areas and by some peoples more than...

psychological test

(Encyclopedia)psychological test, any of a variety of testing procedures for measuring psychological traits and behavior, or for studying some specialized aspect of ability. Several forms of testing have arisen fro...

photoelectric cell

(Encyclopedia)CE5 Photoelectric cell: Light causes a photosensitive surface to emit electrons, which flow as current to the positive terminal. A galvanometer measures the current and thus indicates light intensi...

Fort Worth

(Encyclopedia)Fort Worth, city (2020 pop. 918,915), seat of Tarrant co., N Tex., on the Trinity River 30 mi (48 km) W of Dallas; settled 1843, inc. 1873. An army post...

Iacocca, Lee

(Encyclopedia)Iacocca, Lee (Lido Anthony Iacocca) īˌəkōˈkə [key], 1924–2019, American automobile business executive, b. Allentown, Pa., grad. Lehigh Univ. (1945), Princeton (M.A., 1946). That year he joined...

Hanover, city, Germany

(Encyclopedia)Hanover, Ger. Hannover, city, capital of Lower Saxony, N Germany, on the Leine River and the Midland Canal. It is a major industrial, commercial, ...

Auckland

(Encyclopedia)Auckland ôkˈlənd [key], city (2021 pop. 1,630,092), N North Island, New Zealand. It is situated on an isthmus and is the largest urban region and chief port of the coun...