Q. Why brushes shifting method is not employed in practical commutation?

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Q. Which are the methods for getting an ideal commutation?

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Q. In resistance commutation method we add resistance between __________________

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Q. What is the effect on time constant of transient current, as a result of resistance commutation?

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Q. Which voltage is neutralized in voltage commutation process?

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Q. Interpoles are excited with ____________

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Q. Interpoles are excited by keeping them in ____________ with armature.

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Q. Polarity of interpoles is one pole ahead in the direction of armature rotation in _____________

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Q. What is the size of interpolar air gap compare to main pole air gap?

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Q. For a given 4-pole machine, carrying armature current 56.82 A, with 846 conductors. The mean flux density in the air gap under the interpoles is 0.5 Wb/m² on full load and radial gap length is 0.3 cm. Ampere-turns required for an interpole is ____________

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Q. A 440 V, 4-pole, 25 kW, dc generator has a wave-connected armature winding with 846 conductors. The mean flux density in the air-gap under the interpoles is 0.5 Wb/m² on full load and the radial gap length is 0.3 cm. Number of turns required on each interpole is _________

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Q. To achieve spark less commutation brushes of a DC generator are placed ________

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Q. If in the DC machine, the reversal of current in the coil is faster than ideal or linear commutation then the commutation is said to be __________ commutation.

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Q. For a DC machine, in a commutator ________

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Q. The insulating material used between the commutator segments is normally _______

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Q. Why interpoles are tapered in a DC machine?

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Q. The main function of interpoles in a loaded DC machine is to minimize _______between the brushes and the commutator.

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Q. Which of the following is different component?

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Q. How many coils under an adjoining pole pairs is/are connected between adjacent commutator segments in lap winding?

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Q. In wave winding, P/2 coils are connected under the influence of “x” pole-pairs which connect adjacent segments. X is ____

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