The design of mechanical parts is particularly important in case of __________ speed machines?

Related Mcqs:

1. In D.C. machines, the ________ in field mmf results in increase in size and cost of machines?

   A. increase
   B. decrease
   C. either of the above
   D. none of the above

2. The surge phenomenon is particularly important in case of_______________?

   A. low voltage transformers
   B. medium voltage transformers
   C. high voltage transformers
   D. any of the above

3. Commercial available medium size machines have a speed range of __________ ?

   A. 200 to 400 r.p.m
   B. 600 to 1000 r.p.m
   C. 1000 to 1500 r.p.m
   D. 2000 to 2500 r.p.m

4. In _________ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft?

   A. small
   B. medium
   C. large
   D. any of the above.

5. The action of electromagnetic machines can be related to which of the following basic principles __________?

   A. Induction
   B. Interaction
   C. Alignment
   D. All of the above

6. __________is extensively used for those portions of magnetic circuit which carry steady flux and need superior mechanical properties ?

   A. Grey cast-iron
   B. Cast steel
   C. High carbon steel
   D. Stainless steel

7. Electrical machines having power outputs ranging from a few kW up to approximately 250 kW may be classified as_____________?

   A. small size machines
   B. medium size machines
   C. large size machines
   D. any of the above

8. Electrical machines having a power output up to about 750 W may be called__________machines?

   A. small size
   B. medium size
   C. large size
   D. any of the above

9. Machines cooled by direct cooling method may be called_____________?

   A. “supercharged”
   B. “inner cooled”
   C. “conductor cooled”
   D. any of the above

10. D.C. machines designed with a large value of air gap length have_____________?

    A. worst, ventilation
    B. poor ventilation
    C. better ventilation
    D. none of the above