When a compound wound DC motor is cumulatively compounded, what does this mean?

Correct Answer: Option D — The current flow direction in each series-field coil is in the same direction as the current flow direction in its corresponding shunt-field coil, in which case the field fluxes are additive.

Cumulative compounding occurs when series and shunt field windings are wound so their magnetic fluxes flow in the same direction. These additive fluxes combine to boost starting torque while maintaining better speed regulation than a pure series motor.