Metallic lattice and electrical resistance (1 Viewer)

[Akira_Tikira]

Hi
Let me ask you a question and hope someone is able to help me.

We know that when we hook a metal wire to a potential difference, electron flow and the collision between the electron with the atoms cause energy to be transformed into heat.

Why is it that a metal which is not hooked up to a potential difference do not experience this temperature (this may sound stupid), doesn't electrons randomly drift around the lattice at tremendous speed and must collide with the atom. So there must be some mechanism or all our metals would heat up...

I require an explanation of why this phonenmone doesn't occur

 

[kini mini]

Good question

Short Answer: Conservation of Energy!

Long answer:

Electrons in metals are delocalised, but their kinetic energy has to come from somewhere. This can be provided by the application of a potential difference. I'm sure that electrons are drifting around the lattice to some extent, and transferring their energy to the lattuce, but there can be no net change in the energy of the piece of metal as a whole unless you apply the PD or heat it etc.