Understanding Microscopic Ohm's Law

In summary, the microscopic version of Ohm's Law states that the current density within a conductor is equal to its conductivity multiplied by the E-field. The E-field is a result of a potential difference from a power source and can either be an external field acting upon the wire or an internal field caused by the current density.
  • #1
ed2288
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
 
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  • #2
ed2288 said:

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
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?
 

What is Microscopic Ohm's Law?

Microscopic Ohm's Law is a fundamental physical law that describes the relationship between current, voltage, and resistance in a microscopic scale. It is used to understand the behavior of electric currents in materials at the atomic level.

What is the equation for Microscopic Ohm's Law?

The equation for Microscopic Ohm's Law is I = nqAv, where I is the current, n is the number of charge carriers, q is the charge of each carrier, A is the cross-sectional area of the material, and v is the drift velocity of the carriers.

How is Microscopic Ohm's Law different from Macroscopic Ohm's Law?

Microscopic Ohm's Law takes into account the behavior of individual charge carriers in a material, while Macroscopic Ohm's Law only considers the overall behavior of the material. In other words, Microscopic Ohm's Law is applicable at the atomic level, while Macroscopic Ohm's Law is applicable at the macroscopic level.

What are the assumptions of Microscopic Ohm's Law?

The assumptions of Microscopic Ohm's Law are that the material is uniform and isotropic, that the charge carriers are moving in a straight line, and that the material is in a steady state with no build-up or depletion of charge carriers.

What are some practical applications of Microscopic Ohm's Law?

Microscopic Ohm's Law is used in the design and analysis of electronic devices such as transistors, diodes, and integrated circuits. It is also important in fields such as semiconductor physics, materials science, and electrical engineering.

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