Can Electrons in an Electrically Charged Gas Generate Voltage?

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Discussion Overview

The discussion revolves around the generation of voltage by electrons in electrically charged gases, particularly in the context of fluorescent and gas discharge lamps. Participants explore theoretical concepts related to electromagnetic induction and the behavior of electrons in different current conditions, including AC and DC sources.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether electrons flowing in a fluorescent lamp create an electromotive force (emf) that could induce voltage in copper windings wrapped around the lamp.
  • Another participant acknowledges that variable current flow generates a variable magnetic field but questions the significance of this in terms of induced voltage.
  • Concerns are raised about energy losses in the lamp, with some suggesting that a significant portion is converted to visible light rather than other electromagnetic frequencies.
  • A participant inquires about the effects of applying a DC source to a gas discharge lamp and whether this would induce emf in windings around the tube.
  • One participant asserts that a DC current produces a uniform static magnetic field and suggests that the results would be similar to those in a metallic conductor, indicating no induced voltage.
  • Another participant claims that wrapping copper wire around the tube can induce a current useful for charging devices, citing personal experience in Nigeria.

Areas of Agreement / Disagreement

Participants express differing views on whether induced voltage occurs in the scenarios described, with some asserting that it does not happen under DC conditions while others suggest it could be possible under certain circumstances. The discussion remains unresolved regarding the specifics of induced voltage in these contexts.

Contextual Notes

Participants reference various assumptions about the behavior of gases under different electrical conditions, the nature of electromagnetic fields, and the efficiency of energy conversion in gas discharge lamps. However, these assumptions are not fully explored or agreed upon.

Crazymechanic
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Hello, could you please share some insights on the matters I'm about to ask.

The examples will be without any numbers of real physical dimensions more like theoretical concepts.

In a fluorescent lamp or gas discharge lamp the electrons flow from cathode to cathode(anode ??) as I believe they change places 50/60 times a second because the ac current does so either, but that's not of highest importance here , so the electrons flow exciting the gas(mercury vapor)) atoms which give a UV photon emission on the phosphor coating on the walls which in turn radiate em radiation in the visible spectrum at a certain wavelength.
The questions is while does electrons are traveling in the lamp they not only excite the mercury atoms but create and emf right? Like every moving charge does.So if I would wrap windings of copper around the long tube fluorescent bulb would I see some voltage induced?
Or in this case most if the electron energy is wasted as visible light rather than other forms of em frequencies?


The second question would be , imagine a tube like (possibly made of glass) enclosure , then low pressure gas in it and electrodes at both ends of the tube. A dc current source applied to the electrodes making one cathode the other anode depending on the polarity.
Now assume the voltage is high enough for the gas to conduct, when this happens again the tube has some windings wound in the middle of it would there be induced voltage/current in those windings because of the electron flow perpendicular to them?
 
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So if I would wrap windings of copper around the long tube fluorescent bulb would I see some voltage induced?
As every variable current flow, it generates a variable magnetic field, indeed. So what?
Or in this case most if the electron energy is wasted as visible light rather than other forms of em frequencies?
There are significant non-radiative losses, but a good fraction of the energy gets converted to visible light.
 
Ok, then if the fluorescent gas discharge lamp would be powered from dc source , not taking into account the need for limited current and so just the fact a dc power source now the one end become the cathode the other the anode , electrons flow would that electron flow through the tube induce emf in those windings around the tube or in this case it wouldn't ?
I know that dc has a uniform static magnetic field but I always wondered what happens when that dc is passed along a gas or some other conducting environment ? I guess the same as when it is passed along a wire but still someones approval of my thinking and little explanation would be great.
 
I know that dc has a uniform static magnetic field but I always wondered what happens when that dc is passed along a gas or some other conducting environment ?
That does not matter, you get the same results as with a metallic conductor.
In this case: No induced voltage.
 
Crazymechanic said:
Hello, could you please share some insights on the matters I'm about to ask.

The examples will be without any numbers of real physical dimensions more like theoretical concepts.

In a fluorescent lamp or gas discharge lamp the electrons flow from cathode to cathode(anode ??) as I believe they change places 50/60 times a second because the ac current does so either, but that's not of highest importance here , so the electrons flow exciting the gas(mercury vapor)) atoms which give a UV photon emission on the phosphor coating on the walls which in turn radiate em radiation in the visible spectrum at a certain wavelength.
The questions is while does electrons are traveling in the lamp they not only excite the mercury atoms but create and emf right? Like every moving charge does.So if I would wrap windings of copper around the long tube fluorescent bulb would I see some voltage induced?
Or in this case most if the electron energy is wasted as visible light rather than other forms of em frequencies?


The second question would be , imagine a tube like (possibly made of glass) enclosure , then low pressure gas in it and electrodes at both ends of the tube. A dc current source applied to the electrodes making one cathode the other anode depending on the polarity.
Now assume the voltage is high enough for the gas to conduct, when this happens again the tube has some windings wound in the middle of it would there be induced voltage/current in those windings because of the electron flow perpendicular to them?
Winding a copper wire around the tube will indeed induce a current the wire that is useful enough to charge phone batteries ect. I was in Nigeria a few years ago and saw this regularly done!
 

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