Dummy coil should not be used in_________________?

Related Mcqs:

1. When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of_____________?

   A. short pitch
   B. full pitch
   C. either of the above
   D. none of the above

2. The winding where dummy coils are used is sometimes called______________?

   A. duplex winding
   B. triplex winding
   C. forced winding
   D. none of the above

3. The distance between the starts of two consecutive coils measured in terms of coil sides is called_____________?

   A. front pitch
   B. winding pitch
   C. commutator pitch
   D. back pitch

4. 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

5. __________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

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

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

7. Power transformers should be designed to have maximum efficiency________________?

   A. at one-fourth load
   B. at one-half load
   C. at or near full load
   D. any of the above

8. In a D.C. machine, the value of peripheral speed should not, normally, exceed___________?

   A. 10 m/s
   B. 20 m/s
   C. 30 m/s
   D. 40 m/s

9. A practical formula for determining the thickness of insulation between low voltage and high voltage windings is__________________?

   A. 1 + 0.2 kVmm
   B. 2 + 0.5 kVmm
   C. 4 + 0.7 kV mm
   D. 5 + 0.9 kV mm

10. Multi-layer helical windings are commonly used in the transformers as high voltage windings_______________?

    A. upto 20 kV
    B. upto 50 kV
    C. upto 80 kV
    D. for 110 kV and above