A. Increase in efficiency
B. Increase in ratings
C. Increase in life
D. Smaller size of coolers
E. All of the above
Related Mcqs:
- 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 - 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 - 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 - With conventional hydrogen cooling it is possible to increase the rating of a single unit to___________?
A. 50 MW
B. 100 MW
C. 200 MW
D. none of the above - Which of the following methods is used for air cooling of turbo-alternators ?
A. One sided axial ventilation
B. Two sided axial ventilation
C. Multiple inlet system
D. All of the above - 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 - Machines cooled by direct cooling method may be called_____________?
A. “supercharged”
B. “inner cooled”
C. “conductor cooled”
D. any of the above - Direct water cooling of rotor winding presents_____________?
A. no mechanical difficulties
B. lesser mechanical difficulties
C. greater mechanical difficulties
D. none of the above - With direct water cooling it is possible to have ratings of about_____________?
A. 200 MW
B. 300 MW
C. 400 MW
D. 600 MW - 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
