Two infinite lines of current in the same direction

In summary, the conversation discusses the calculation of magnetic field and forces between two parallel lines of current using the right hand rule and Ampere's law. It also raises the question of why a coaxial line, modeled as multiple lines of current, does not close in on itself and concentrates the current in the center. The explanation given is the mutual repulsion of like charges.
  • #1
datran
14
0
I heard this question from my TA and was not satisfied with the answer. Can someone elaborate for me please?

There are two infinite lines of current that are traveling in the same direction. By the right hand rule and ampere's law, we can calculate the magnetic field and calculate the F of one line on the other.

The forces are pointed toward each other, so they will get closer and closer.


A coaxial line can be modeled as many infinite lines of current bundled together. How come the wires do not close themselves in and therefore the current should be concentrated within the center of the coaxial wire.

If we were to send an AC voltage down the line, there should be only surface current, yet our previous analysis indicates that the lines should be pulled closer to each other therefore concentrating the current in the center of the coaxial wire.

Any explanation will be much appreciated!

Thank you!
 
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  • #2
Well, there is the mutual repulsion of like charges ...
 

Related to Two infinite lines of current in the same direction

1. How do two infinite lines of current in the same direction interact with each other?

Two infinite lines of current in the same direction will produce a magnetic field that is parallel to both lines. This magnetic field will cause the lines to repel each other, creating a force that pushes them away from each other.

2. What is the strength of the magnetic field between two infinite lines of current in the same direction?

The strength of the magnetic field between two infinite lines of current in the same direction is directly proportional to the current in each line and inversely proportional to the distance between the lines. As the distance between the lines increases, the strength of the magnetic field decreases.

3. Can two infinite lines of current in the same direction cancel each other out?

No, two infinite lines of current in the same direction cannot cancel each other out. Since the magnetic field they produce is parallel, they will always repel each other and never cancel out.

4. How does the current in one line affect the magnetic field produced by the other line?

The current in one line has a direct effect on the strength of the magnetic field produced by the other line. As the current increases, the strength of the magnetic field also increases, resulting in a stronger repulsive force between the two lines.

5. What is the mathematical equation for the force between two infinite lines of current in the same direction?

The force between two infinite lines of current in the same direction can be calculated using the equation F = μ0*I1*I2/2πd, where μ0 is the permeability of free space, I1 and I2 are the currents in each line, and d is the distance between the lines.

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