• Support PF! Buy your school textbooks, materials and every day products Here!

Microscopic Ohm's Law

  • Thread starter ed2288
  • Start date
  • #1
25
0

Homework Statement


Explain the terms used in the microscopic version of Ohm's Law


Homework Equations


j=oE



The Attempt at a Solution


Well I know what we have here is the current density within a conductor is equal to its conductivity multiplied by an 'E-field'. But what is this E-field? Is it an external field that acts upon the wire? But if this is the case will the electrons in the conductor not just move in a few microseconds to go back into equilibrium meaning j=0. You could act on it with an varying field but then how would the calculation work out?
Or is E the field inside the conductor caused by the current density?
Thanks
 

Answers and Replies

  • #2
LowlyPion
Homework Helper
3,090
4

Homework Statement


Explain the terms used in the microscopic version of Ohm's Law


Homework Equations


j=oE

The Attempt at a Solution


Well I know what we have here is the current density within a conductor is equal to its conductivity multiplied by an 'E-field'. But what is this E-field? Is it an external field that acts upon the wire? But if this is the case will the electrons in the conductor not just move in a few microseconds to go back into equilibrium meaning j=0. You could act on it with an varying field but then how would the calculation work out?
Or is E the field inside the conductor caused by the current density?
Thanks
Maybe this helps?
http://hyperphysics.phy-astr.gsu.edu/HBASE/electric/ohmmic.html
 
  • #3
25
0
Hmmm I guess I've spent so long doing electrostatics that I'm struggling a bit with the intuition of currents.
So from the link above, am I right in thinking the E field is from within the wire caused by a potential difference from a power source?
 

Related Threads for: Microscopic Ohm's Law

  • Last Post
Replies
2
Views
27K
  • Last Post
Replies
15
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
3
Views
3K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
1
Views
945
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
1
Views
2K
Top