When an aluminum plate is placed between two wires (lying parallel to each other), it doesn't change the repelling nor attracting force between the wires when a current is passing through them.
But when you encouter with a magnet a coil of wire there is a current induced in this coil and by Lenz'law the coil will produce an equal magnetic field which would repel the magnet.
Now I should expect that this also would happen with the two wires, that in the aluminium plate an equal magnetic field is induced no matter what direction the current is. But this doesn't happen. Why not? Or did I mix things up?