Demagnetizing action refers to the process of reducing or removing the magnetism from a material. This can be done by subjecting the material to a strong alternating magnetic field or heating it above its Curie temperature to randomize the magnetic domains and reduce the overall magnetization.

To remove the magnetic properties from an electromagnet, you can disrupt the alignment of the magnetic domains in the core material by heating it above its Curie temperature or by demagnetizing it using a demagnetizing coil. This will randomize the arrangement of the magnetic domains and eliminate the magnetic field.

it is the flux which is flowing opposite to the main field flux and demaganetize it...

in order to eliminate this demagnetiszing component we have to connect the compensating winding in series with the armature winding which develop the flux in it oppose to the demagnetizing component

To demagnetize a gold plated chain, you can try gently rubbing a demagnetizing tool (such as a demagnetizing wand) along the chain in a smooth motion. Alternatively, you can expose the chain to a strong magnetic field in the opposite direction to the magnetization to cancel out the magnetism. Be gentle to avoid damaging the delicate gold plating.

The quality of the attractive field diminishes with separation from the wire.