# I Forces between two straight conductors

1. Feb 9, 2017

### LogarithmLuke

Hi, im having trouble figuring out how the forces work between two straight conductors with currents going through them. I know that when the currents go the same way, the forces are attractive, and when the currents go opposite ways, the forces are repelling. I know one has to use the right hand rule, but i just cant figure out how to do it to get it right.

Could someone help clear this up?

2. Feb 9, 2017

3. Feb 9, 2017

### LogarithmLuke

Im aware of what the magnetic fields around the wires look like, the trouble comes with finding the direction of the forces between to conductors.

4. Feb 9, 2017

### BvU

That's exactly what I'm avoiding by first establishing a B field from wire 1 -- after which I can forget wire 1. Wire 2 then experiences a Lorentz force in that B field.
Hyperphysics in fact does it the same way (1 = left, 2= right wire)

5. Feb 11, 2017

### lychette

can you sketch the field patterns for each wire. Can you sketch the resultant field pattern for 2 wires when the currents are in the same direction and in opposite directions. In the same direction the combined field is (visually) attractive.
In opposite directions the combined field is (visually) repulsive.