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Home Fundamentals The Electron Velocity of Electrons in a Vacuum Tube  
See also: The Charge of the Electron, The Mass of the Electron, The Klystron  
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Velocity of Electrons in a Vacuum TubeAuthor: J.B. Hoag
The equation connecting the voltage E and the velocity v is as follows: Ee/300 = mv^{2}/2, where e is the charge of the electron in electrostatic units and m is its mass in grams. This equation is accurate to within 1 per cent up to 7,000 volts. For higher voltages, a more complicated relativity equation must be used. The righthand side of the equation is a wellknown expression for the energy of moving bodies. This "kinetic" energy is expressed in units called "ergs". An energy of 1.60·10^{10} ergs will be acquired by an electron speeded up by means of a 100volt battery. Thus 1 electron volt is equivalent to 1.60·10^{12 }ergs. The electron volt is abbreviated "eV" and is often used today in referring to the velocity of a charged particle. It should be clear, however, that the volt is a measure of the energy of the particle rather than its velocity.


Home Fundamentals The Electron Velocity of Electrons in a Vacuum Tube 