Question

The purpose of using inter-poles in large DC machines is to nullify:

• A. The de-magnetizing & cross magnetizing effect of armature mmf
• B. The heating effect due to copper losses
• C. The eddy currents
• D. Constant losses

Hint:

Inter-poles are used to improve commutation in large DC machines by compensating for the armature's magnetic effects on the main field.

Answer 1

The Correct Option is A

In large DC machines, inter-poles are used to neutralize the de-magnetizing and cross magnetizing effects produced by the armature's magnetic field. These effects can distort the main field and cause poor commutation. By placing inter-poles, the magnetic field is made more uniform, and the effects of the armature mmf are neutralized. Thus, the primary purpose of inter-poles is to nullify the de-magnetizing and cross magnetizing effects of the armature mmf.