follow Dictionary.com

How do you spell Hannukah?

rheostat

[ree-uh-stat] /ˈri əˌstæt/
noun, Electricity
1.
an adjustable resistor so constructed that its resistance may be changed without opening the circuit in which it is connected, thereby controlling the current in the circuit.
Origin
1843
1843; rheo- + -stat
Related forms
rheostatic, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for rheostat
  • Connects battery to battery charger and adjusts rheostat to start flow of electricity into battery.
  • Employ the lowest rheostat setting on your instrument that shows detail and color to your satisfaction.
British Dictionary definitions for rheostat

rheostat

/ˈriːəˌstæt/
noun
1.
a variable resistance, usually consisting of a coil of wire with a terminal at one end and a sliding contact that moves along the coil to tap off the current
Derived Forms
rheostatic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for rheostat
n.

1843, coined by English physicist Sir Charles Wheatstone (1802-1875) from Greek rheos "a flowing, stream" (from PIE root *sreu-, see rheum) + -stat "regulating device." Related: Rheostatic.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
rheostat in Science
rheostat
  (rē'ə-stāt')   
See under resistor.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Article for rheostat

adjustable resistor used in applications that require the adjustment of current or the varying of resistance in an electric circuit. The rheostat can adjust generator characteristics, dim lights, and start or control the speed of motors. Its resistance element can be a metal wire or ribbon, carbon, or a conducting liquid, depending on the application. For average currents, the metallic type is most common; for very small currents, the carbon type is used; and for large currents the electrolytic type, in which electrodes are placed in a conducting fluid, is most suitable. A special type of rheostat is the potentiometer, an instrument that measures an unknown voltage or potential difference by balancing it, wholly or in part, by a known potential difference. A more common potentiometer is simply a resistor with two fixed terminals and a third terminal connected to a variable contact arm; it is used for such purposes as a volume control in audio equipment.

Learn more about rheostat with a free trial on Britannica.com
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for rheostat

Few English speakers likely know this word

Word Value for rheostat

11
10
Scrabble Words With Friends

Nearby words for rheostat