Object is used as the core of the coil is the magnetic field intensity. Temporary magnet substance Mild steel or a magnetic field with high intensity. And widely used for electromagnetic .
As the object used as the axis of the coil is what tells the saturation magnetic field. Message magnetic soft steel or cause a magnetic field with a high intensity electromagnetic and used .
It is an object that is used as a winding axis of said magnetic field strength magnetic substances temporary or light steel, the magnetic field is used to make popular and high-intensity Electromagnetic Fields