can you make an electromagnet with ac current
Electromagnet The energy loss per cycle of the AC current is constant for each of these processes, so the power loss increases linearly with frequency.
Earth's magnetic field The Earth's magnetic field is believed to be generated by electric currents in the conductive material of its core, created by convection currents due to heat escaping from the core. However the process is complex, and computer models that reproduce some of its features have only been developed in the last few decades.