Increase in kinetic energy in current carrying conductor

[carlyn medona]

Homework Statement

If I have two current carrying conductor carrying current is same direction, they move towards each other so kinetiisc energy increases. So which force does work here?

Homework Equations

The Attempt at a Solution

I know magnetic force can't do work, is work done by some external factor ?

 

[kuruman]

I know magnetic force can't do work ...

How do you know that? If that's the case, how do you explain a pin jumping off a table top and sticking to a refrigerator magnet hovering above it? Be careful with how you generalize what.

 

[lekh2003]

I know magnetic force can't do work, is work done by some external factor ?

Kuruman is correct. I'm going to let you in on the secret... it does do work. The question you should be asking is how it does work.

The right hand rules should help you out. If you do not understand what those are, take a look at this pdf from a physics textbook: http://fcis.aisdhaka.org/personal/chendricks/IB/Giancoli/Giancoli Ch 20 Magnetism.pdf

Look at Page 9, it should have a summary of the ways magnetic fields and currents interact.