Electric field due to current carrying conductor

In summary: The electric field is about the strength of surface charges divided by permittivity of the medium outside the wire.In summary, the presence of a constant current carrying conductor can result in a non-zero electric field, which can have both attractive and repulsive effects on static charges depending on their position. This is due to the accumulation of charges on the surface of the wire, rather than the relativistic contraction of lengths within the wire.
  • #1
pranav p v
29
3
Does static charge near to a constant current carrying conductor experience force on it?
I am asking this question because i have learned that electric field and mangnetic field are same thing but viewing differently with respect to the frame of reference...when a positive test charge moves ( parallel to the wire) near to the current carrying conductor ,with respect to the positive charge positive ions in the conductor are moving and due to length contraction charge density due to positive ions will be higher so net electric field will be present. that will repel the test charge... So magnetic field in the rest frame is actually electric field in the test charge's moving frame..i am ok with this .but consider when that test charge at stationary position ,it sees the length contraction of electrons ( which are moving) ... So there will be an attractive electrical force ...but if I think like the following,wire is actually neutral because at a time,number of electrons enter into the wire equal to number of electrons leave ...so in that way static test charge will not experience any force. I feel contradiction...help me

I am repeating my question, electric field due to current carrying conductor is zero or not??
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
pranav p v said:
I am repeating my question, electric field due to current carrying conductor is zero or not??
For an ideal conductor it is zero. Real conductors may be slightly non zero, but for all practical purposes (including relativistic effects) you can consider it zero for a good conductor.

How familiar are you with four-vectors. The easiest explanation uses them.
 
  • #3
pranav p v said:
Does static charge near to a constant current carrying conductor experience force on it?

...but consider when that test charge at stationary position ,it sees the length contraction of electrons ( which are moving) ... So there will be an attractive electrical force ...but if I think like the following,wire is actually neutral because at a time,number of electrons enter into the wire equal to number of electrons leave ...so in that way static test charge will not experience any force. I feel contradiction...help me

I am repeating my question, electric field due to current carrying conductor is zero or not??

It is not zero in general, and can be quite measurable, indirectly, as electric potential that decreases the farther from the wire you go. The direction of this field when near the wire is along the wire, when farther from wire, more radial and hard to determine - it depends on the objects in the vicinity of the wire.

The relativistic contraction of lengths does not mean that density of negative charge is necessarily higher than density of positive nuclei. The interior of the wire is to a high accuracy neutral, since any local excess is electrostatically unstable and is quickly disrupted by movable electrons from the surrounding metal.

The major effect on the electric field outside the wire is due the same charges that produce electric field inside the wire - the charges on the surface of the wire. The surface of the wire is a boundary that the charges cannot easily cross so accumulation and excess of charges can persist there. And it has to, if there is to be non-zero electric field inside the wire. These charges have nothing to do with contraction of lengths, but everything to do with resistance of the wire. For same current and wire diameter, the higher the resistance of the wire, the greater the density of surface charges.
 

1. What is an electric field?

An electric field is a region in which an electric charge experiences a force. It is a fundamental concept in physics that describes the influence of electric charges on each other through the force of attraction or repulsion.

2. What is a current carrying conductor?

A current carrying conductor is a material, such as a wire, that allows electric current to flow through it. It is usually made of a metal or other conductive material and is used to transmit electricity from one point to another.

3. How does a current carrying conductor create an electric field?

When an electric current flows through a conductor, it creates a magnetic field around the conductor. This changing magnetic field then induces an electric field in the surrounding space. The strength of the electric field is directly proportional to the current flowing through the conductor.

4. What is the direction of the electric field due to a current carrying conductor?

The direction of the electric field due to a current carrying conductor is perpendicular to the direction of the current flow and follows the right-hand rule. This means that if you point your thumb in the direction of the current, your fingers will curl in the direction of the electric field.

5. How does the electric field due to a current carrying conductor affect nearby charges?

The electric field due to a current carrying conductor can exert a force on nearby charges. If the nearby charges are positive, they will be attracted towards the conductor, while negative charges will be repelled. This effect is used in many applications such as motors, generators, and transformers.

Similar threads

Replies
3
Views
489
  • Electromagnetism
Replies
17
Views
1K
  • Electromagnetism
Replies
11
Views
758
  • Electromagnetism
Replies
14
Views
1K
  • Electromagnetism
Replies
4
Views
973
  • Electromagnetism
Replies
7
Views
957
  • Electromagnetism
Replies
15
Views
1K
  • Electromagnetism
Replies
5
Views
317
Replies
4
Views
1K
Replies
4
Views
1K
Back
Top