Induction and Halbach array

Question

I have recently studied and tried to understand the concept of the Inductrack, a form of magnetic levitation.

In the following link they present three different ways to construct the track: http://cegt201.bradley.edu/projects/proj2004/maglevt1/inductrack.html

The first one is pretty straightforward, basically utilizing wire coils as you would expect from any simple induction experiment.

But with the other two methods I have a bit of trouble understanding the workings behind them, hopefully someone here can help.

The third method (utilizing the laminated slotted copper sheets):
from what I understand this would basically be the same as horizontally aligned wire coils and due to the sinusoidal nature of the magnetic field there is still induction when the array is moved.
Is this correct?
If so, is the orientation of the wire coils completely irrelevant to the effectiveness of the system?
Or is there an alignment that would be optimal?

This brings me to the second method utilizing wire rungs.
Here every wire is shortened to every other wire in the pack. Is this setup better than any of the other two in terms of effectiveness?

Which would physically speaking be the ideal way to construct the track?

Answer 1

When you are clear about eddy current (in superconductors) and Lenz's law then you can easily find out the answer. Eddy current will be created in superconductors when they exposed to external magnetic field, that eddy current will induce an electromagnetic field and the direction of the magnetic field will always be opposite to the original magnetic field (applied field). Hence these two opposite lines of force will oppose each other which causes the object with the induced magnetic field to float.