Objective Questions on Alternators

16. A winding is having a number of slots is equal to the number of poles, then this winding is called

(A) concentrated winding.
(B) short pitch winding.
(C) full pitch winding.
(D) distributed winding.

17. Symmetrical waveform does not have

(A) capacitance.
(B) odd harmonics.
(C) both even and odd harmonics.
(D) even harmonics.

18. A synchronous machine

(A) can operate at unity power factor.
(B) can operate at leading power factor.
(C) can operate at lagging power factor.
(D) can operate at any power factor.

19. A winding is having number of slots is greater than number of poles, then this winding is called

(A) concentrated winding.
(B) distributed winding.
(C) full pitch winding.
(D) integrated slot winding.

20. When the number of slots / pole / phase is fractional, then this winding is called

(A) short pitch winding.
(B) full pitch winding.
(C) fractional slot winding.
(D) integral slot winding.

21. When the number of slots / pole / phase is integer, then this winding is called

(A) fractional slot winding.
(B) integer slot winding.
(C) concentrated winding.
(D) short pitch winding.

22. Which alternator are more suitable for the high-speed system?

(A) Salient pole.
(B) Non-salient pole.
(C) Both (A) and (B).
(D) None of these.

23. The number of poles in turbo alternator are

(A) 2.
(B) 6.
(C) 8.
(D) 10.

24. When two alternator are operating in parallel and at perfect synchronization, their synchronizing power will be

(A) negative.
(B) infinite.
(C) positive.
(D) zero.

25. The stationary alternator must not be connected to live bus bars because it will results _______________ .

(A) short circuit.
(B) open circuit.
(C) nothing will happen.
(D) floating.

26. Floating of alternators with busbars occurs at when

(A) synchronized generated emf is less than the busbar voltage.
(B) synchronized generated emf is greater than the busbar voltage.
(C) synchronized generated emf is equal to the busbar voltage.
(D) none of above.

27. Which of the following conditions is to be fulfilled, for connecting an alternator to infinite bus?

(A) Phase sequence should be same.
(B) Frequency is need not same.
(C) Terminal voltage of alternator need not to be same with existing bus.
(D) None of above.

28. If a slot consists of one coil side then the winding is called

(A) double layer winding.
(B) full pitch winding.
(C) single layer winding.
(D) short pitch winding.

29. If the slot consists 2 coil sides of different coils is called

(A) double layer winding.
(B) single layer winding.
(C) concentric winding.
(D) distributed winding.

30. Distributed winding and short chording employed in AC machine will result in

(A) increase in emf and reduction in harmonics.
(B) decrease in emf and increase in harmonics.
(C) increase in both.
(D) decrease in both.