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

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

   A. low
   B. medium
   C. high
   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. 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

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. Multiple inlet system of air cooling of turbo-alternators can be used for machines of rating upto_______________?

   A. 10 MW
   B. 30 MW
   C. 60 MW
   D. 150 MW

7. In D.C. machines the width of the duct is usually_____________?

   A. 4 mm
   B. 6 mm
   C. 8 mm
   D. 10 mm

8. In D.C. machines the usual limit of slot pitch is________________?

   A. between 5 to 10 mm
   B. between 10 to 15 mm
   C. between 15 to 20 mm
   D. between 25 to 35 mm

9. In D.C. machines the number of slots per pole usually lies___________?

   A. between 2 to 4
   B. between 6 to 8
   C. between 9 to 16
   D. between 20 to 30

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