Columbia Encyclopedia

Search results

500 results found

thermoelectricity

(Encyclopedia)thermoelectricity, direct conversion of heat into electric energy, or vice versa. The term is generally restricted to the irreversible conversion of electricity into heat described by the English phys...

dielectric

(Encyclopedia)dielectric dīˌĭlĕkˈtrĭk [key], material that does not conduct electricity readily, i.e., an insulator (see insulation). A good dielectric should also have other properties: It must resist breakd...

Eagleton, Thomas Francis

(Encyclopedia)Eagleton, Thomas Francis, 1929–2007, U.S. senator (1968–87), b. St. Louis, Mo. Admitted to the bar in 1953, he entered Democratic politics in Missouri and served as circuit attorney for St. Louis ...

fuel cell

(Encyclopedia)fuel cell, electric cell in which the chemical energy from the oxidation of a gas fuel is converted directly to electrical energy in a continuous process (see oxidation and reduction). The efficiency ...

antenna

(Encyclopedia)antenna ăntĕnˈə [key], in electronics, system of wires or other conductors used to transmit or receive radio or other electromagnetic waves (see radio); sometimes called an aerial. The idea of usi...

typewriter

(Encyclopedia)typewriter, instrument for producing by manual operation characters similar to those of printing. Corresponding to each key on the instrument's keyboard is a steel type. Activated through a series of ...

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...

Armstrong, Edwin Howard

(Encyclopedia)Armstrong, Edwin Howard, 1890–1954, American engineer and radio inventor, b. New York City, grad. Columbia (E.E. 1913). He was associated in research with Michael I. Pupin at Columbia and became pro...

potentiometer

(Encyclopedia)potentiometer. 1 Manually adjustable, variable, electrical resistor. It has a resistance element that is attached to the circuit by three contacts, or terminals. The ends of the resistance element are...

microphone

(Encyclopedia)microphone, device for converting sound into electrical energy, used in radio broadcasting, recording, and sound amplifying systems. Its basic component is a diaphragm that responds to the pressure or...