an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents.
choobRead more in this article about some frequently asked questions and fun facts related to our definitions.
If you see an odd glow in the sky tonight, here’s what it’s called and its causeYou’ve heard of the northern lights? The next few days you may be able to see lights even if you aren’t that far north. The sun erupted on Sunday, spewing plasma, “a highly ionized gas containing an approximately equal number of positive ions and electrons” right in our direction. There’s no reason to freak out; solar storms are relatively common, and the most significant impact they have on …
- electron probe microanalysis,
- electron radiography,
- electron spin resonance,
- electron telescope,
- electron transport,
- electron volt,
- electron-ray tube,
Origin of electron tube
First recorded in 1920–25
Also called electronic tube.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
an electrical device, such as a valve, in which a flow of electrons between electrodes takes placeAlso called: vacuum tube Sometimes shortened to: tube
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
A sealed glass tube containing either a vacuum or a small amount of gas, in which electrons move from a negatively charged electrode, the cathode, to a positively charged one, the anode. The cathode is usually heated by an electric current to free the electrons. Other electrodes in the tube can vary the electric or magnetic fields in the tube to control the strength and direction of the moving electrons. Electron tubes are used to amplify signals, rectify AC currents, and produce x-rays, among other uses. They have been mostly replaced by transistors but are still used in television screens, computer monitors, and microwave technology. Also called valve See also vacuum tube.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.