Does there exist any electric field inside a charged conductor?

  • #1
We know that there exists no electric field inside a conductor. But while calculating drift velocity of electrons inside an electric conductor, why do we consider the electrons are present inside the charged conductor?
 

Answers and Replies

  • #2
Dale
Mentor
Insights Author
2020 Award
31,951
8,857
We know that there exists no electric field inside a conductor.
There certainly can exist an electric field inside a conductor. The electric field is proportional to the current density for ordinary conductors. This is known as Ohm's law
 
  • Like
Likes FactChecker
  • #3
Is it electric field or electric current?
 
  • #4
nasu
Gold Member
3,786
439
Is it electric field or electric current?
Both. The electric field drives the electric current.
 
  • #5
4
1
What you're referring to is probably what you get told in electrostatics at first, but the lack of an electric field is actually the condition for the static state, it can exist and as mentioned here causes a current to flow, this is now electrodynamics
 
  • Like
Likes Anindya Mondal
  • #6
1,370
381
On the atomic scale there are always significant electric fields but these average out.
 
  • #7
What you're referring to is probably what you get told in electrostatics at first, but the lack of an electric field is actually the condition for the static state, it can exist and as mentioned here causes a current to flow, this is now electrodynamics
Yeah, I refer to electrostatics
 
  • #8
vanhees71
Science Advisor
Insights Author
Gold Member
18,822
9,688
In electrostatics by definition you assume that all fields are time independent and that all current densities are vanishing, ##\vec{j}=0##. Now you have (in non-relativistic approximation) ##\vec{j}=\sigma \vec{E}##, where ##\sigma## is the electric conductivity of your medium. For a conductor ##\sigma \neq 0##, which implies that ##\vec{E}=0##, because in the electrostatic case you have by definition ##\vec{j}=0##.
 
  • #9
In electrostatics by definition you assume that all fields are time independent and that all current densities are vanishing, ##\vec{j}=0##. Now you have (in non-relativistic approximation) ##\vec{j}=\sigma \vec{E}##, where ##\sigma## is the electric conductivity of your medium. For a conductor ##\sigma \neq 0##, which implies that ##\vec{E}=0##, because in the electrostatic case you have by definition ##\vec{j}=0##.
I can't understand, please be elaborate.
 
  • #10
vanhees71
Science Advisor
Insights Author
Gold Member
18,822
9,688
What don't you understand? It's very simple. In electrostatics by definition the current density vanishes. In a conductor, according to Ohm's Law, the current density is proportional to the electric field and thus the electric field must vanish within the conductor. I don't know, how I can this elaborate more.
 

Related Threads on Does there exist any electric field inside a charged conductor?

Replies
14
Views
9K
  • Last Post
Replies
7
Views
1K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
6K
  • Last Post
Replies
14
Views
1K
  • Last Post
Replies
8
Views
3K
  • Last Post
Replies
13
Views
2K
  • Last Post
2
Replies
37
Views
10K
  • Last Post
Replies
3
Views
2K
Top