What are the Forces on parallel ac conductors

In summary, two long parallel conductors A and B are carrying an ac current with a wavelength of λ, separated by λ/4 at all points. The ac current phase of conductor A leads the current phase of conductor B by λ/4 at all points mutually at right angles between the two conductors. This results in a force directed towards conductor B on conductor A and a force directed away from conductor A on conductor B. However, despite the forces being in the same direction, there will not be a net force that would move both conductors towards each other due to the varying magnetic field and other factors. This is a scenario that has not been addressed before.
  • #1
Tracer
63
0
The Scenario:
Two long parallel conductors A and B are carrying an ac current with a wave length of λ. The conductors are separated in distance at all points by λ/4 and the ac current phase of conductor A leads the ac current phase of conductor B by λ/4 at all points mutually at right angles between the two conductors.
The Problem:
Conductor A will always be in a field radiated from Conductor B that is exactly in phase with the actual phase of conductor A's current. Consequently conductor A will experience a force directed toward conductor B.
Conductor B will always be in a field radiated from conductor A that is exactly 180° out of phase with with the actual phase of conductor B's current. Consequently conductor B will experience a force directed away from conductor A.
Since forces on both conductors are in the same direction it seems that a net force would exist that would tend to move both conductors in a direction from conductor A towards conductor B.
The question: Why will this not happen?
 
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  • #2
Hi Tracer! :smile:

What is the effect of the varying magnetic field?
 
  • #3
tiny-tim said:
Hi Tracer! :smile:

What is the effect of the varying magnetic field?

Aside from inducing currents in other conductors?

This is not a homework problem tiny-tim. It is a scenario that I have never seen addressed anywhere.
a more graphic of the problem is presented in the EMRPHASES1.doc atachment.

Regards, Tracer.
 

Attachments

  • EMRPHASES1.doc
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FAQ: What are the Forces on parallel ac conductors

What are the forces on parallel AC conductors?

The forces on parallel AC conductors are primarily electromagnetic forces. These forces are caused by the interaction between the electric and magnetic fields generated by the flow of alternating current through the conductors. The magnitude and direction of the forces depend on the current, distance between the conductors, and the phase relationship between the currents in the two conductors.

How do these forces affect the conductors?

These forces can cause the conductors to attract or repel each other. If the two conductors have currents flowing in the same direction, they will experience an attractive force. On the other hand, if the currents are flowing in opposite directions, the conductors will experience a repulsive force. These forces can cause the conductors to move, which can lead to mechanical stress and potentially damage the conductors.

What factors affect the magnitude of these forces?

The magnitude of the forces on parallel AC conductors depends on several factors, including the current in the conductors, the distance between them, and the frequency of the alternating current. Additionally, the shape and size of the conductors can also affect the magnitude of the forces. Thicker and longer conductors will generally experience greater forces.

How can these forces be minimized?

To minimize the forces on parallel AC conductors, the distance between the conductors can be increased. This reduces the interaction between the electric and magnetic fields, resulting in smaller forces. Additionally, using conductors with a lower current or a lower frequency can also help reduce the forces. Proper insulation and support for the conductors can also help prevent excessive movement and stress.

Are these forces only present in AC systems?

No, these forces can also be present in DC systems, but they are typically much smaller. This is because the magnetic fields in DC systems are constant, whereas in AC systems, they are constantly changing. Therefore, the forces on parallel DC conductors are typically negligible and do not need to be considered in most cases.

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