⟩ Explain me what if there are no compensation windings?
In the absence of compensation windings the flux will be suddenly shifting backward and forward with every change in load inducing an e.m.f in the armature coils. The magnitude of this e.m.f may be so high as to strike an arc between the consecutive commutator segments. This may further develop into a flash-over around the whole commutator thereby short circuiting the whole armature.