what is the function of the field coils of a DC motor?

They provide a magnetic field that is opposite that of the rotating axle. Here is an interactive site that may help although this site has paermanent magnets for the field magnetism.
(Broken Link Removed)

THANK U DrBob222

The function of the field coils in a DC motor is to create a magnetic field that interacts with the armature, which is the rotating part of the motor. When an electric current flows through the field coils, a magnetic field is generated, and the direction of this field is opposite to that of the rotating axle or armature.

The interaction between the magnetic field generated by the field coils and the armature results in the production of torque, which causes the armature to rotate. This rotational motion is then used to drive mechanical devices connected to the motor, such as fans, pumps, or machinery.

To understand the function of field coils further, you can refer to websites or online resources that provide interactive demonstrations or simulations of DC motors. Unfortunately, I am unable to provide specific links or recommendations for such resources at the moment.