How fast do CRTs shoot electrons?

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SUMMARY

CRTs (Cathode Ray Tubes) shoot electrons at speeds significantly less than the speed of light due to the mass of electrons, which prevents them from reaching light speed according to special relativity. The average speed of electrons in a CRT is approximately 1.18 x 107 m/s when accelerated by a voltage of 400 V, translating to about 4% of the speed of light. In larger tube TVs, with an accelerating voltage of around 25,000 V, electrons can reach speeds of approximately one-third the speed of light. This information is crucial for understanding the operational mechanics of CRT technology.

PREREQUISITES
  • Understanding of special relativity and its implications on mass and speed
  • Basic knowledge of electron behavior in electric fields
  • Familiarity with CRT technology and its components
  • Knowledge of voltage and energy conversion in electron acceleration
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  • Research the effects of voltage on electron acceleration in CRTs
  • Explore the principles of special relativity as they apply to particle physics
  • Investigate the differences in electron speeds across various display technologies, including LCD and OLED
  • Learn about the historical context and evolution of CRT technology in television
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Physics students, electrical engineers, and technology enthusiasts interested in the mechanics of CRT displays and electron dynamics.

Ralphonsicus
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Thanks.
 
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It must be less than the speed of light.
 
Yes I know that because electrons have mass and therefore (according to special relativity) they cannot reach light speed. But that wasn't the question, the question was HOW FAST do CRTs shoot electrons (on average)?
 
Ralphonsicus said:
Yes I know that because electrons have mass and therefore (according to special relativity) they cannot reach light speed. But that wasn't the question, the question was HOW FAST do CRTs shoot electrons (on average)?

With a quick bit of googling I found that the voltage of a CRT TV cathode is 400 V. Therefore an electron accelerated will obtain 400 eV of energy. The speed of an 400 eV electron is 1.18*10^7 m/s or ~4% of the speed of light.
 
Oops, don't know how I came up with 400 V. Maybe that's for a ye olde oscilloscope or something.
 
Haha it's grand, thanks all.
 

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