A. Increase in efficiency
B. Increase in ratings
C. Increase in life
D. Smaller size of coolers
E. All of the above
0
The density of hydrogen is __________ times the density of air?
0
Machines cooled by direct cooling method may be called_____________?
A. 0.07
B. 1.5
C. 2.5
D. 3.5
0
The resistivity of water should not be less than_____________?
A. “supercharged”
B. “inner cooled”
C. “conductor cooled”
D. any of the above
0
In direct cooled system using hydrogen both stator and rotor conductors are made____________?
A. 10 Q m
B. 100 Q m
C. 1000 Q m
D. 2000 Q m
0
Direct water cooling of rotor winding presents_____________?
A. solid
B. hollow
C. perforated
D. any ofthe above
0
In self cooled motors the cooling time constant is about ___________ than the heating time constant because cooling conditions are worse at standstill?
A. no mechanical difficulties
B. lesser mechanical difficulties
C. greater mechanical difficulties
D. none of the above
0
With direct water cooling it is possible to have ratings of about_____________?
A. 2 to 3 times greater
B. 3 to 4 times greater
C. 4 to 5 times greater
D. none of the above
0
The time taken by the machine to attain 0.632 of its final steady temperature rise is called_____________?
A. 200 MW
B. 300 MW
C. 400 MW
D. 600 MW
0
Which of the following methods does not take into account the maximum temperature rise under variable load conditions ?
A. heating time constant
B. cooling time constant
C. either A. or B.
D. none of the above
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