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Connect an ideal battery across two end of a superconductor?

  1. Sep 14, 2013 #1
    Hi,
    What will happen if I connect an ideal battery across two ends of a superconductor?
    Assume all contacts are ideal, lossless.
    Is the current infinitive?
     
    Last edited: Sep 15, 2013
  2. jcsd
  3. Sep 15, 2013 #2
    What is an ideal battery? The one whose internal resistance is zero?
     
  4. Sep 15, 2013 #3
    Yes.
     
  5. Sep 15, 2013 #4

    Drakkith

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    Staff: Mentor

    Mathematically, sure.
    Just realize that this is impossible in the real world.
     
  6. Sep 15, 2013 #5
    Then the current will grow till the magnetic field becomes so strong that the superconductor will stop being a superconductor, or is torn apart by mechanical stress from the growing magnetic field, whichever happens first.
     
  7. Sep 15, 2013 #6

    Drakkith

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    Staff: Mentor

    There's also the fact that it isn't possible to have a battery with 0 resistance. Even with a resistance close to zero, the battery would discharge so fast it would explode. It is using a chemical reaction to generate electricity, after all.
     
  8. Sep 15, 2013 #7
    An ideal battery cannot be chemical almost by definition. There are in fact special-purpose generators with very low internal resistance that can generate huge currents, albeit for very brief periods of time. I guess we could imagine this "ideal battery" is such a generator.
     
  9. Sep 15, 2013 #8

    Drakkith

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    Staff: Mentor

    Well, then it wouldn't be a battery at all, would it?
    I'm curious as to how they even generate current in a superconductor normally. Is it induced somehow? But perhaps that is a question for another thread.
     
  10. Sep 21, 2013 #9
    Hi,
    For example, assuming that we have the battery ideal with no internal resistance and all contacts, wires are ideal (no resistance).
    Then, theoretically, the voltage/current across/through two ends of the wire is indeterminate, right?
    And this configuration even impossible in theory.
     
  11. Sep 21, 2013 #10
    No. There will always be certain effects that make this impossible. An example was given in #5.
     
  12. Sep 21, 2013 #11

    Dale

    Staff: Mentor

    This is merely a modern version of the "unstoppable force against an immovable object" paradox.

    There is no such thing as an ideal battery. There are superconductors, but even those can only support a finite current density before they cease being superconducting. Both of those realities will prevent infinite current.
     
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