Important Electrical Machine Design Multiple Choice Questions and Answers

36.  Hydro generators are designed for a maximum peripheral speed of about

   A. 140 m/s

   B. 175 m/s

   C. 75 m/s

   D. 250 m/s

37.  Use of higher B _av in synchronous machines causes increase in

   A. Iron losses

   B. Synchronizing power

   C. Short circuit current

   D. All of the above

38.  Use of higher specific electrical loading in synchronous machines reduces

   A. Copper losses

   B. Synchronous reactance

   C. Synchronizing power

   D. Stray load losses

39.  The use of silent poles on high-speed synchronous machines will cause

   A. Excessive windage loss

   B. Excessive noise

   C. Reduced windage loss

   D. Both A and B

40.  A synchronous machine with longer air gap will have

   A. Lower stability limit

   B. Smaller unbalanced magnetic pull

   C. Higher noise level

   D.. Poor ventilation

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