Is the direction of electric field the direction of current?

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Discussion Overview

The discussion centers on the relationship between the direction of the electric field and the direction of conventional current. It explores theoretical and conceptual aspects, particularly in the context of conductive materials and various charge carriers.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants argue that the direction of the electric field is not the same as the direction of conventional current, as the current is defined by the flow of positive charge, while the electric field drives the motion of electrons.
  • Others suggest that in conductive materials, the direction of current and the electric field can be the same and are proportional, referencing Ohm's law.
  • One participant points out that positive charges flow from a positive plate to a negative plate, which aligns with the direction of the electric field, but acknowledges that electrons are the actual charge carriers.
  • A later reply introduces the concept of free charges in a vacuum, where currents can exist without an electric field, adding complexity to the discussion.
  • Some participants mention anisotropic materials, such as graphite, where the current density may not align with the electric field direction, indicating a more advanced consideration of the topic.

Areas of Agreement / Disagreement

Participants generally disagree on the relationship between the electric field and conventional current, with multiple competing views presented. The discussion remains unresolved regarding the implications of different scenarios, such as conductive materials versus free charges in vacuum.

Contextual Notes

The discussion includes references to specific conditions, such as the behavior of charges in anisotropic materials and the implications of Ohm's law, which may not be universally applicable in all contexts.

StevenJacobs990
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Is the direction of electric field save as the direction of (conventional) current?
 
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StevenJacobs990 said:
Is the direction of electric field save as the direction of (conventional) current?

no, it's in the direction of charge flow ... electron direction. It is the electric field that drives the motion of the electrons/charge
 
StevenJacobs990 said:
Is the direction of electric field save as the direction of (conventional) current?
@davenn is correct. In general the electric field and the current are not in the same direction.

However, in the special case of a current inside a conductive material the direction of the current and the direction of the E field are the same and they are proportional to each other. This is the meaning of Ohm's law
 
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davenn said:
no, it's in the direction of charge flow ... electron direction. It is the electric field that drives the motion of the electrons/charge
Careful here. Th direction of Positive charge is defined by the direction of the field. That is the direction of the conventional current. Signs need to be observed meticulously and that post doesn't make it as clear as it should. Anyone who is struggling will need to make a conscious effort to realize minus times minus is plus when doing the sums.
StevenJacobs990 said:
Is the direction of electric field same as the direction of (conventional) current?
I would say that is perfectly correct and that bringing electrons in is not relevant here. The sign of the particles carrying the current is something that comes in much later.
 
Dale said:
@davenn is correct. In general the electric field and the current are not in the same direction.

However, in the special case of a current inside a conductive material the direction of the current and the direction of the E field are the same and they are proportional to each other. This is the meaning of Ohm's law
I don't get this. Positive charges will flow from a positive plate to a negative plate. That is also direction of the Field, isn't it? It may be that electrons are carrying the charge but that doesn't affect the conventional current.
Did you have something else in mind? I'm sure you must have.
 
sophiecentaur said:
Did you have something else in mind?
I was thinking of free charges in vacuum, where you can have currents (charge velocity) without an E field (charge acceleration).
 
Dale said:
I was thinking of free charges in vacuum, where you can have currents (charge velocity) without an E field (charge acceleration).
That's a relief! :smile:
But I'm reading the OP and assuming it is a question about the everyday situations of circuits, currents, devices and PD, In any of those situations, charge will flow (or at least be displaced) in the direction of any net Electric field.
I think it's time to give the OP a chance to respond and give us a better clue about the level of his question.
 
jtbell said:
There are anisotropic materials (e.g. graphite) in which the resistivity is described by a tensor, and the current density at a point is not necessarily in the same direction as the electric field.

https://en.wikipedia.org/wiki/Elect...ty#Tensor_equations_for_anisotropic_materials

This is a rather advanced topic, though. I don't remember seeing it in an introductory textbook.
Yes. It's a scientific truth but does it help with the OP's question? Seasoned PF members don't always take not of the Code Letter, associated with the title. It's a B, in this case, meaning basic High School Level.
 

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