Magnetic fields are generated either by moving (also called electric currents) or by changing . For example, in an electric motor, electric current produces a magnetic field which forces the motor to turn.
Moving charged in atoms create a tiny electrical current, which produces a magnetic field. Thus atoms such as iron carry a magnetic field.
The cause of the is not well understood, but seems to be caused by electrical currents in the core. The magnetism of old rocks is called .
also have magnetic fields, probably caused by rotations of hot ionized in the star. These magnetic fields cause spots on the .
is made from electric and magnetic fields.
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