Speed Control of DC motor by Armature Resistance Control

A 4 pole generator with 16 coil has a two layer lap winding. The pole pitch is
Line joining tangent and Torque line in a circle diagram gives
Two electrical wires run to a machine. One wire is 6mm thick, and the other is 3mm thick. For the two wires to carry the same current, the larger wire
Difference in speed between stator field and rotor
Shape of the torque slip curve is