The winding where dummy coils are used is sometimes called______________?

Related Mcqs:

1. cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall______________?

   A. Direct
   B. Indirect
   C. Conventional
   D. Any of the above

2. Dummy coil should not be used in_________________?

   A. small machines
   B. large machines
   C. either A. or B.
   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. A current density of __________ is ilsed for large power transformers with forced circulation of oil or with water cooling coils?

   A. 1.5 to 2.5 A/mm2
   B. 3.5 to 4.5 A/mm2
   C. 4.0 to 5.0 A/mm2
   D. 5.4 to 6.2 A/mm2

5. Direct water cooling of rotor winding presents_____________?

   A. no mechanical difficulties
   B. lesser mechanical difficulties
   C. greater mechanical difficulties
   D. none of the above

6. The high voltage winding is usually which of the following type ?

   A. Cylindrical winding with circular conductors
   B. Cross-over winding with either circular or small rectangular conductors
   C. Continuous disc type winding with rectangular conductors
   D. All of the above types

7. The change in flux linkages can be caused in which of the following ways ?

   A. The flux is constant with respect to time and is stationary and the coil moves through it
   B. The coil is stationary with respect to flux and the flux varies in magnitude with respect to time
   C. Both the changes mentioned above occur together, i.e., the coil moves through a time varying field
   D. All of the above

8. Hydrogen has a heat transfer co-efficient __________ times that of air?

   A. 1.5
   B. 2.5
   C. 3.5
   D. 4.5

9. By which of the following methods the temperature rise of windings and other parts may be determined ?

   A. Thermometer method
   B. Resistance method
   C. Embedded temperature detector method
   D. Any of the above

10. The cylindrical windings using circular conductors are used for current rating of____________?

    A. upto 20 A
    B. upto 40 A
    C. upto 60 A
    D. upto 80 A