Mutual Induction and Law of Conservation of Mass

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Discussion Overview

The discussion revolves around mutual induction and its relationship with the conservation of energy, specifically questioning the source of voltage generated in a secondary coil when influenced by a primary coil's magnetic field. Participants explore the energy dynamics involved in this process, including scenarios with open circuits and the implications for electromagnetic fields.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the origin of the voltage generated in the secondary coil, suggesting it cannot be created and must come from a conversion of energy from the magnetic field.
  • Another participant asserts that the energy does indeed come from the magnetic field of the first coil.
  • It is noted that if the second coil is an open circuit, no energy flows to it despite the presence of an electromotive force due to the varying magnetic field.
  • A participant expresses confusion about the relevance of a previous response to the original question regarding energy transfer from the primary field.
  • Further questions are raised about whether the primary magnetic field loses energy over time and how this relates to the attraction of iron objects by electromagnetic fields.
  • One participant suggests that if the primary circuit is not replenished, the primary field does lose energy, which affects the secondary coil.
  • There is uncertainty expressed regarding the specifics of energy loss in the context of electromagnetic fields attracting objects.

Areas of Agreement / Disagreement

Participants generally agree that the energy for the induced voltage comes from the primary coil's magnetic field, but there is disagreement about the implications of energy loss and the specifics of how it operates in different scenarios, such as open circuits and the attraction of iron objects.

Contextual Notes

Some participants express uncertainty about the mechanics of energy transfer and loss in mutual induction, particularly in relation to open circuits and the behavior of electromagnetic fields.

Nishantkumar19
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In mutual induction, when a coil is turned on or off, it generates voltage in another nearby coil. But where is that voltage coming from? It can't be created, so what form of energy does it convert from?

As far as I know, when the magnetic field cuts across the coil, that generates voltage, but does the magnetic field itself lose energy that is being converted to voltage in the second coil?
 
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Yes, the energy comes from the magnetic field, which comes from the first coil.
 
Drakkith said:
Yes, the energy comes from the magnetic field, which comes from the first coil.
If the second coil is open circuit, no energy flows to it. When the first coil has a varying magnetic field, as with AC, it applies an electro motive force to the electrons in the secondary, but as there is an open circuit they cannot move and so no energy is absorbed.
 
tech99 said:
If the second coil is open circuit, no energy flows to it. When the first coil has a varying magnetic field, as with AC, it applies an electro motive force to the electrons in the secondary, but as there is an open circuit they cannot move and so no energy is absorbed.

What does this have to do with the OP's question or my response?
 
Drakkith said:
What does this have to do with the OP's question or my response?
My apologies if I have missed the point, but the questioner seemed to be asking if, to induce a voltage in a nearby coil, energy is taken from the field of the primary, and that was the direction of my reply.
 
tech99 said:
My apologies if I have missed the point, but the questioner seemed to be asking if, to induce a voltage in a nearby coil, energy is taken from the field of the primary, and that was the direction of my reply.

I see. It seemed like you were chiming in just to point out something about an open circuit. No worries.
 
Does that mean the primary field loses energy over time?

Does the same apply for when an electromagnetic field attracts iron objects?

Is it the size of the field that diminishes, or the attracting energy itself?

Thanks for all your help.
 
Nishantkumar19 said:
Does that mean the primary field loses energy over time?

If not replenished by the primary circuit, yes. That's why when you turn of the primary, the secondary side shuts off too.

Nishantkumar19 said:
Does the same apply for when an electromagnetic field attracts iron objects?

That is beyond my expertise.
 

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