Electron gun

Electrons are accelerated towards an anode and pass through a hole, at high speed. To convert the energy gained in electron Volts to Joules (Coulomb Volt) multiply by the charge of the electron.

Energy gained = V x 1.6x10-19 Joules

The velocity is found by making the energy in Joules equal to the kinetic energy of the fast moving electron.

In a cathode ray tube with an anode voltage of 3000iVolts, the electron velocity is the value of v in the equation....

1/2mv2 = eV

v = (2eV/m)0.5

= (2 x 1.6x10-19 x 3x103/ (9.11x10-31))0.5

= (1.05x10(-19 + 3 + 31))0.5

= (10.5x1014)0.5

= 3.2x107 m/s

... 10% of the speed of light!