# How can I calculate the force between finite coil and metal plate?

1. Aug 1, 2014

### eastblue

Hi,

I would like to calculate the force between a finite coil and a nearby metal plate. A pulsed current is supposed to flow into the magnetic coil, which will generate a magnetic field near the coil. Due to this magnetic field, an Eddy current will be produced in a nearby metal plate and finally there will be a repulsion between the coil and the plate.

I was able to calculate the magnetic field on the metal plate, but I am not sure how to calculate the force between the coil and the plate. Can we actually calculate the Eddy current? Is there easier way to estimate the force without calculating the Eddy current? Any suggestion would be welcome.

Thanks.

2. Aug 2, 2014

### Simon Bridge

The coil will have a magnetic field due to the current in the coil.
Part of the magnetic field will be near the plate.
The magnetic field produces eddy currents - well done.
When the magnet is first switched on and brought close it repels the plate.

If the plate is iron-like, it may be attracted to a stationary constant magnet. You need to know how the plate responds to a magnetic field - this is a material property that you look up.
Also see: