Six point charges , each of the same magnitude q, are arranged in different manners as shown in Column II . In each case, a point M and a line PQ passing through M are shown . Let E be the electric field and V be the electric potential at M (potential at infinity is zero ) due to the given charge distribution when it is at rest . Now, the whole system is set into rotation with a constant angular velocity about the line PQ . Let B be the magnetic field at M and `mu` be the magnetic moment of the system in this condition . Assume each rotating charge to be equivalent to a steady current .

Answer

`(##JA_09_PHY_P1_E08_001_A01##)`