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Faraday's Law

  1. Jun 20, 2004 #1


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    Why is it that a changing magnetic flux through a surface should induce an emf? I know that the emf is from a non-conservative electric field, but how exactly was this field generated? (if that is the correct expression for it)
    Last edited: Jun 23, 2004
  2. jcsd
  3. Jun 22, 2004 #2
    When someone gives you an answer as to why this happens, won't you just want to know why whatever answer they gave happens? What will this explanation tell you, exactly?

    In my humble opinion whether you accept a paradigm a famous scientist offers you shouldn't depend on whether there is a more fundamental explanation proposed later, but instead depend on wether you can verify it to be a good predictor - which with Faraday's Law is easy to do.
  4. Jun 22, 2004 #3
    THe apearance of the emf is due to the transformation of the B field to the reference frame of the wire. The transformation laws are governed by the Lorenz equations. I guess this explanation ( given in more detail) is a more fundamental and satisfactory one. Dont forget Faraday was an experimental guy. It's an experimental law
  5. Jun 22, 2004 #4
    I've never met a physicist who took anything on faith. To be honest, I don't recall anyone who seriously studies science taking anything on faith.
    I've also never met anyone who seriously studies science who didn't think when learning a theory.
    You've never learned it because nobody knows the answer to that question. I.e. it's one of Maxwell's equations and those equations are postulates, i.e. not derivable from from other postulates.

    For details please see - http://rustam.uwp.edu/202/lec18_19.html

    Last edited by a moderator: Apr 21, 2017
  6. Jun 22, 2004 #5


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    This is the nature of an inquisitive mind. If it weren't for people asking why, we would still be in the realm of classical physics, with no motivation to advance.

    And I apologize if my original post seemed to be confrontational to anyone; the people on this board are obviously the last people one would expect to take things on faith. It just seemed like a sensible question to ask.
  7. Jun 22, 2004 #6
    No problemo! I all the years I've been posting in physics boards on the internet I've seen many people think that physicists are just gulible people who believe anything a prof tells them too. I don't know why people make that assumption so much but it does seem to be a common theme to those people who are not scientists.

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