# Magnetic forces on plates

1. Aug 17, 2009

### munozcim

Dear all,

I've found in many books forces acting between 2 parallel wires, but not between a magnetic field and a surface. Let's now imagine a conducting plate which is within a magnetic field. Which is the resultant force acting on that panel?

Raúl

2. Aug 17, 2009

### fatra2

Hi there,

Thinking about it, your question should boil down to a wire in an electric field. I assume that you plate is conductive. What happens to the "free" charges in a conductive plate??? (come on this is simple).

From this result, you can apply a wire current within a magnetic field.

Cheers

3. Aug 17, 2009

### espen180

If you are talking about two plates of evenly distributed current, I should think you can integrate the forces to find the answer.

It reminds me of the problem of the forces two equally and linearly uniformly charged rods excert on each other.

Last edited: Aug 17, 2009
4. Aug 17, 2009

### munozcim

Thanks fatra2 and espen180 for your quick reply. Actually I'm thinking about a lightning strike which is acting on a conductive plate. The current flows from the attachment point to the whole plate in a radial way in all directions. The plate can be assumed as isotropic.
The magnetic field created by the lightning strike acts on the conductive plate pushing it downwards. I would like to know the value of that pushing force.
cheers

5. Aug 18, 2009

### fatra2

But no matter what, once your lightning strikes the conductive plates, the extra free charges will redistribute on the edge of the plate. Therefore, applying current in a wire could be applied.

Cheers