Hello everyone! I am new to Comsol Multiphysics. I need to study the oersted field generated in a bilayer structure of Permalloy (Ni 80%, Fe 20%) and Platinum. I am using AC/DC module and using external current density to input a current in the whole structure. I am inputting J in x direction. When I calculate magnetic field, I am getting a varying magnetic field which has been induced from the external current density. I want to know if the current is DC, why is the magnetic field AC? I am attaching my comsol file as well.
Thanks in advance.