Wire in E Field: Will it Deflect?

• cragar
In summary, the conversation discusses the possibility of a current carrying wire deflecting in an E field and whether there would be any changes if the observer was in motion. It is suggested that if there is a voltage across the wire, there would be an E field down the wire, similar to a plate capacitor. However, it is also mentioned that there may be a B field from an external E field, which could potentially balance out any forces experienced by the wire.
cragar
If I had a current carrying wire in an E field. Would it deflect? The wire it self just has a B field and no free charge. But If I was moving with respect to the wire I would see length contraction and a net E field. So in my frame the wire would deflect. Or is something wrong with my reasoning?

cragar said:
If I had a current carrying wire in an E field. Would it deflect?
I expect it wouldn't. But let's make it more interesting, and use a length of resistance wire so there is significant potential across the wire. (Make it of carbon and delicately suspend it with elastic quartz fibres to avoid arguments.) Would it experience deflecting forces now with a few hundred volts P.D.?
But If I was moving with respect to the wire I would see length contraction and a net E field. So in my frame the wire would deflect. Or is something wrong with my reasoning?
I can't comment.

so if we have a suspended wire with a voltage across it, so There is an E field down the wire, so it is basically like a plate capacitor. So if we have a charge separation in the wire
the +q and -q charged will experience forces in the opposite directions and should cancel.

cragar said:
so if we have a suspended wire with a voltage across it, so There is an E field down the wire, so it is basically like a plate capacitor. So if we have a charge separation in the wire
the +q and -q charged will experience forces in the opposite directions and should cancel.
I think the more positive end of the wire will be pushed by the E field (i.e., attracted towards the negative plate) and the negative end of the wire will be attracted by the E field (i.e., attracted towards the positive plate), so the wire will tend to rotate about an axis through its centre.

So torque on an Electric dipole.

Now that I think more about my original post, an looking at this in the moving frame.
If I move with respect to this wire an I get a net E field from the wire, I will also get a B field from the external E field, and this will cause a Lorentz force F= q(vxB) and this will
probably balance the F=qE from the E field.

1. Can a wire in an electric field be deflected?

Yes, a wire in an electric field can be deflected. When an electric field is applied to a wire, it exerts a force on the electrons in the wire, causing them to move and the wire to deflect.

2. How does the direction of the electric field affect the deflection of a wire?

The direction of the electric field determines the direction of the force exerted on the electrons in the wire. If the electric field is parallel to the wire, there will be no deflection. If the electric field is perpendicular to the wire, there will be maximum deflection.

3. What factors affect the amount of deflection in a wire in an electric field?

The amount of deflection in a wire in an electric field is affected by the strength of the electric field, the length and mass of the wire, and the charge of the particles in the wire. Additionally, the material and thickness of the wire can also influence the amount of deflection.

4. Can a wire be deflected in a uniform electric field?

Yes, a wire can be deflected in a uniform electric field. The deflection will be the same at all points along the wire, as long as the strength of the electric field is constant.

5. Can a wire be deflected in a non-uniform electric field?

Yes, a wire can be deflected in a non-uniform electric field. However, the amount of deflection will vary at different points along the wire due to the varying strength of the electric field.

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