Q. For 6252 AT/Poles, if brush shift is of 2.50 mech. Degrees, what will be the cross-magnetizing ampere-turns per pole for a 6-pole DC machine?

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Q. The armature reaction in a DC machine causes distortion in the main field flux. Effect of armature reaction can be reduced by_________

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Q. In order to neutralize armature mmf perfectly under the pole shoe, the ampere-conductors of compensating winding must be (pole arc/pole pitch=1) _______

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Q. What is the ampere turns per pole for compensating winding in DC machines?

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Q. Where are no equalizer rings connected?

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Q. Inequality in brush arm currents caused due to different emf induced in different parallel paths may give rise to copper losses. These effects can be avoided by using _________

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Q. Which of the following method will completely neutralize the armature reaction in a DC machine?

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Q. What is the exact location of compensating winding?

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Q. Exact purpose of compensating winding in a DC generator is _________

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Q. Function of interpole flux is_________

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Q. Why dummy coils are connected in DC machine?

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Q. The most likely cause(s) of sparking at the brushes in a DC machine is /are ____________

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Q. Each of the following statements regarding interpoles is true except______________________

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Q. Axis undergo shifting as a result of armature reaction, can be balanced by ______

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Q. The choice of average coil voltage determines the minimum number of commutator segments for its design.

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Q. Compensating winding will provide incomplete neutralization ____________

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Q. Cross-magnetizing effect of armature reaction can be reduced by __________

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Q. To counter the effect of shift in MNA due to armature reaction, which of the following component can be shifted?

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Q. Calculate the number of conductors on each pole piece required in a compensating winding for a 6-pole lap-wound dc armature containing 286 conductors. The compensating winding carries full armature current. Assume ratio of pole arc/ pole pitch = 0.7.

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Q. A compensating winding with ampere-turns greater than peak ampere turns is required in order to neutralize the effect of armature reaction because _____________

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