The work of the magnetic force

[Eitan Levy]

Homework Statement

We put 2 very long parallel wires on a table, in both of them the current flows at the same direction. As a result, they get closer to each other.
Does this create a conflict with the fact that magnetic force does not do work?
What is the energy source for the work done on the wires?

Homework Equations

Irrelevant

The Attempt at a Solution

Honestly I Just can't figure this out, any help would be appreciated.

 

[BvU]

Hi Ethan,

PF rules forbid help if no attempt is made, so 'dunno' is not good enough, I'm afraid...

what energy sources are there in this scenario ?

 

[Eitan Levy]

Hi Ethan,

PF rules forbid help if no attempt is made, so 'dunno' is not good enough, I'm afraid...

what energy sources are there in this scenario ?

I just don't really know. The only source I can think of is the magnetic force.

 

[BvU]

the fact that magnetic force does not do work

 

[Eitan Levy]

I know it doesn't, but what can be the source of energy in here? Normal and gravity don't seem to be the sources to me, so what can be the source?

 

[Eitan Levy]

Can anyone give a hint? I really have no clue.

 

[CWatters]

Consider an electric motor which is a similar set up. What does that need in order to make it spin/rotate a load?