The principle of operation of the electric motor of direct current can also be verified through the principle of attraction and repulsion between magnetic fields, due to the interaction of the magnetic field. The force against electromotive force or generated voltage is induced in the winding of the armature.

The magnet represents the field winding where in the lower part is the south pole and in the upper part the north pole of the magnet. The armature winding is in turn connected to a direct current source rab lighting through the brushes and the switch; current flows through the armature winding. Due to this current a magnetic field is caused around the conductor of the armature, whose direction is given by the rule of the right hand. This field interacts with the field of the magnet and then a force arises and causes the armature winding to rotate.

Between the second and third stages the direct current is the same as that of the armature winding and also in the power supply, causing the force to have the same direction. The switch makes the sense be the same, due to the fact that it does the mechanical rectification, otherwise the resulting force on the armature winding would be zero.