Magnetic Fields from Magnets and Currents

Magnetic fields come from moving electric charges and from magnetic materials such as bar magnets. A current is one example of moving charge. The magnetic field made by a current can be calculated with the Maxwell equation.

Bar magnets also create magnetic fields. In magnetic materials, the field...

Magnetic fields are fundamental to electromagnetism and underlie many practical applications ranging from compasses to magnetic resonance imaging.

Magnetic fields or B-fields can be generated by moving charges, such as an electrical current, or objects such as bar magnets due to the microscopic dynamics of charges inside the magnetic mater...