Self Assessment Quiz

1. Solve the London equation to determine the field variation inside a flat slab of very large surface area and of thickness d, placed in a magnetic field H parallel to the plane of the slab.

2. In the limit , why is complete flux expulsion not achieved ?

3. What can you deduce about the current flow in a superconducting wire from the fact that B=0 within a superconductor ?

4. A long cylinder of a superconducting material is placed in an axial magnetic field. The critical field of this configuration is determined. Now, a sphere is made of the same material and it's behaviour in an applied magnetic field is measured. It is found that even at fields less than the critical field of the material, there are normal (non-superconducting) regions inside the sample? Explain this anomaly.