Inductance of an inductor in large Steady state Magnetic field

Discussion in 'Physics' started by wes, Jul 4, 2012.

  1. wes

    Thread Starter Active Member

    Aug 24, 2007
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    So would the inductance of a inductor be effected if it was in a large magnetic field. Example, would the inductance of a inductor change if it was in say a MRI?

    MRI's use a steady state magnetic field right? as in not changing, no oscillations.

    If so would it add to the inductance or would it decrease it? Also why?
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    Does the inductor have a magnetic core or is it an air cored inductor?
     
  3. wes

    Thread Starter Active Member

    Aug 24, 2007
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    umm could be eithier or. I am just wondering what effects the MRI or whatever is generating the steady state magnetic field will have on a inductor within it's field. I assume if it was a air cored inductor, then any effect on the inductor would be tiny. If it was a magnetic core, then the effects would be much greater I assume because of the magnetic core lining up with the larger MRI (Electromagnet) magnetic field orientation. Especially since the MRI or electromagnet's field would be many many times greater than the inductor
     
  4. t_n_k

    AAC Fanatic!

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    I think you have effectively answered your own question.

    Something that might give some more useful insights would be a search on the topic of magnetic amplifiers and saturable reactors.
     
  5. wes

    Thread Starter Active Member

    Aug 24, 2007
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    Thanks, I will look those up.
     
  6. BillO

    Well-Known Member

    Nov 24, 2008
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    MRI does employ a constant magnetic field, but that is not the end of it. It also employs RF fields to achieve its goal. The overall field in an MRI machine is not steady state.

    To play with your question. It would depend on the nature of the inductor. If it was a non-ferrous coil, then I'd say absolutely no. However, there are other materials that might produce a different result. But this is not related to MRI.

    More to the point, the human body contains lots of materials that would be 'affected' by large constant fields. Water is the one that MRI depends upon. Mostly because it is so prevalent. However, the effect is not one of a change in what we would normally term inductance, although it is an 'induced' effect.

    MRI actually relies more on QED than classical electromagnetism.

    How far do you need to delve into this?:)
     
  7. wes

    Thread Starter Active Member

    Aug 24, 2007
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    not really all that far, just wanted to get a rough idea of what happens.
     
  8. wes

    Thread Starter Active Member

    Aug 24, 2007
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    Actually I was just thinking and it would be useful to know how to figure this out. So how would you go about trying to figure out how much a large steady state magnetic field would effect a inductor. Like say a 1 Tesla magnetic field and a 10 mh inductor with a iron core or some other high permeable core.
     
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