[ Physics ] Open Question : [PHYSICS]How to - "Prove that the magnetic field at the centre of a sphere is zero when _____ ?

Prove that the magnetic field at the centre of a sphere is zero when two wires are placed perpendicularly on it surface on two different points and a current is running through it . How to prove that the induced magnetic field is zero at the centre of the circle I know how to do it for a ring , but for a sphere ... im not sure. pls take any variables of your choice...ill understand.

Source: http://answers.yahoo.com/question/index?qid=20120904025924AAY1WRH

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