False

Compensating windings are not embedded in the pole faces and they do not have the same polarity as the adjoining armature winding.

Explanation:

Compensating windings are a type of auxiliary winding used in DC machines, typically in the form of interpoles or commutating poles. They are placed on the stator or armature core and are connected in series with the armature winding.

1. Purpose of compensating windings:

The primary purpose of compensating windings is to reduce commutation problems in DC machines. Commutation refers to the process of converting alternating current in the armature winding to direct current in the brushes and external circuit. During commutation, the brushes slide over the commutator segments, and as the armature coils pass under the brushes, the current must be commutated from one coil to the next without any sparking or arcing.

2. Role of compensating windings:

Compensating windings help in achieving sparkless commutation by producing a magnetic field that counteracts the armature reaction. Armature reaction is the distortion of the main magnetic field due to the armature current flowing through the armature winding. This distortion can cause sparking and poor commutation.

3. Placement and polarity:

Compensating windings are placed in the slots or teeth of the stator or armature core, but they are not embedded in the pole faces. They are positioned in such a way that their magnetic field opposes the armature reaction.

The compensating windings are connected in series with the armature winding, but they have opposite polarity to that of the adjoining armature winding. This means that when the armature winding produces a magnetic field in one direction, the compensating winding produces a magnetic field in the opposite direction. This counteracts the armature reaction and helps to maintain a more uniform magnetic field in the air gap.

Conclusion:

In conclusion, compensating windings are not embedded in the pole faces and they have opposite polarity to that of the adjoining armature winding. They are used to reduce commutation problems and improve the performance of DC machines.