Thread: conduction
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newshound newshound is offline
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Default conduction

On 03/06/2021 14:02, williamwright wrote:
If two conductors are merely touched together electricity can flow
between them. That just seems too easy somehow. I mean, just touching?
That's ridiculous. I've always thought that it ought to need more
intimate bonding between conductors for current to flow. Even if the
conductors aren't touching, sometimes there's a spark.

Another question. Why do I wonder about such things?


What do you mean by "merely touched"?

Once there is any contact force, there is a contact area and assuming
the metals are clean, a constriction resistance (which you can look up
for yourself).

Actually if you bring two copper wires close enough then Van der Waals
forces will cause them to be attracted together so if they are flexible
enough they will end up in contact.

And even if they are not touching, put a potential drop across them and
even if the dielectric strength of the air is not exceeded, there will
be some quantum tunnelling.

There are very few stupid questions.