How do we explain electrical resistivity and heat.

[Naty1]

I was looking in my old physics text in connection with another thread and the text said high speed electron collisions and slow speed drift of electrons with an applied electric field don't explain resistivity very well...yielding resistivities 100 times or more than observed.

The electrons do not make as many collisions as classical theory predicts. Theories based on quantum physics agree well with experiment. Classical theory predicts correctly that metals obey ohms law, buit cannot rpedict the numerical value of resistivity.

For a plain old resistor, not an exotic semiconductor or such, what's an explanation resistance and associated electrical heating?

Also, I noticed tungsten has only 3.3 times the resistivity of copper...so why does it get so hot?? Basically because we make it so thin in filament bulbs? R = p[l/A]??

 

[Naty1]

I should have added "classical explanations of " to my post:

and the text said classical explanations of high speed electron collisions and slow speed drift of electrons...

It seems that normal high speed electron collisions continue to occur (this would be a classical view) when an electric potential is applied and a slow speed electron drift results from the applied potential...but there must be something that changes dramatically when a potential is applied as significant heat is typically produced. Maybe electrons are being knocked further out of their typically stable orbits in a resistor? and give off radiation (heat) as they return to lower energy orbits??

 

[Naty1]

This looks like what I was trying to figure out...will log it here for future reference:

http://tau.nanophys.kth.se/cmp/hall/node1.html