When a conducting cylinder is put in a constant magnetic field it perturbes the magnetic field lines. We have already looked at the field lines inside the cylider, now we will look at the lines immediatly outside the cylinder.

If mu is very high, it pulls the field lines into it. The largest petubations to the field are on the axis along the unperturbed lines of bo would be.

In this graph mu was set at 200 and the inputed bo field was .2 div per line or 5 lines per unit. At the area of greates pertubation it is 8 lines per division, 1.6 times greater than bo.

When you have a superconductor, no b lines penatrate the cylider. This pushes the lines out of the cylinder's way and as expected the greatest pertubation occurs where the lines get squeezed out of the way the most, at the top of the cylinder.

The strength of the constant magnetic field is the same in both diagrams, but in this case the strength of the perturbed field is 6 lines in the .5 div between the end of the cylinder and the marking for the 2^nd div. This repretents a field strength of 12 lines per div. or 2.4 times bo.