connect an ideal battery across two end of a superconductor?


by anhnha
Tags: battery, connect, ideal, superconductor
anhnha
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#1
Sep14-13, 11:41 PM
P: 149
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?
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voko
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#2
Sep15-13, 12:25 AM
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What is an ideal battery? The one whose internal resistance is zero?
anhnha
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#3
Sep15-13, 12:59 AM
P: 149
Quote Quote by voko View Post
What is an ideal battery? The one whose internal resistance is zero?
Yes.

Drakkith
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#4
Sep15-13, 01:15 AM
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connect an ideal battery across two end of a superconductor?


Mathematically, sure.
Just realize that this is impossible in the real world.
voko
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#5
Sep15-13, 01:17 AM
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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.
Drakkith
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#6
Sep15-13, 01:26 AM
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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.
voko
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#7
Sep15-13, 01:55 AM
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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.
Drakkith
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#8
Sep15-13, 01:58 AM
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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.
anhnha
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#9
Sep21-13, 09:42 PM
P: 149
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.
voko
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#10
Sep21-13, 10:15 PM
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No. There will always be certain effects that make this impossible. An example was given in #5.
DaleSpam
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#11
Sep21-13, 10:24 PM
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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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