he …… creates flux which will create an emf that cancels out the induced emf in the coil undergoing commutation        *Pole shoeInterpolesCommutatorBrushes

The correct term that fills in the blank is "Interpoles."

Explanation:

Interpoles are small auxiliary poles used in DC machines, particularly in shunt and compound wound motors, to improve performance during the commutation process. They create a magnetic field that produces a flux which counteracts the induced electromotive force (emf) in the coil undergoing commutation. This cancellation of the induced emf is crucial to minimize sparking at the commutator and ensures smooth operation of the motor.

In summary:

• Pole shoe: An integral part of the machine that helps to direct magnetic flux.
• Commutator: A device that reverses the direction of current in the coil.
• Brushes: Conducting components that make contact with the commutator to control the flow of current.

In these contexts, interpoles play a vital role in enhancing the performance and efficiency of DC machines by providing a corrective magnetic field during commutation.