Direct water cooling of rotor winding presents_____________?

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. With direct water cooling it is possible to have ratings of about_____________?

   A. 200 MW B. 300 MW C. 400 MW D. 600 MW...

3. In self cooled motors the cooling time constant is about ___________ than the heating time constant because cooling conditions are worse at standstill?

   A. 2 to 3 times greater B. 3 to 4 times greater C. 4 to 5 times greater D. none of the above...

4. Transformers with a capacity of up to __________ have a cooling radiator system with natural cooling?

   A. 2 MVA B. 5 MVA C. 7.5 MVA D. 10 MVA...

5. In direct cooled system using hydrogen both stator and rotor conductors are made____________?

   A. solid B. hollow C. perforated D. any ofthe above...

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

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

7. 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...

8. The noise produced by a ___________ cooled machine is less as the rotor moves in a medium of smaller density?

   A. air B. hydrogen C. either A. or B. D. none of the above...

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

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

10. 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...