1. The problem statement, all variables and given/known data We have a very long ferromagnetic cylinder with square cross section, with side length a. Cylinder is homogeneosly magnetized over his volume so that the magnetization vector is parallel to the axis of cylinder. Cylinder is in vacuum. Find the current appeared in the cylinder because of the presence of the vector M. Find the vector H and B at the center of cylinder. 2. Relevant equations 3. The attempt at a solution Since M=Jxn it means that current in the cylinder is equal to M by intensity with the direction shown in the picture But i don't know how to determine H and B in the center of the cylinder, i mean i could use generalized Amphere's law to find H and then easily find B but i don't know how, because i don't see what kind of symmetry would work here. Could anyone help me out here?