A. 2 to 3 times greater
B. 3 to 4 times greater
C. 4 to 5 times greater
D. none of the above
Related Mcqs:
- Machines cooled by direct cooling method may be called_____________?
A. “supercharged”
B. “inner cooled”
C. “conductor cooled”
D. any of the above - For large power transformers, self oil cooled type or air blast type which of the following values of current density may be used?
A. 1.0 to 1.2 A/mm2
B. 1.5 to 2.0 A/mm2
C. 2.2 to 3.2 A/mm2
D. 3.2 to 4.2 A/mm2 - 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 - 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 - 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 - In direct cooled system using hydrogen both stator and rotor conductors are made____________?
A. solid
B. hollow
C. perforated
D. any ofthe above - In induction motors, the length of air gap in kept as small as mechanically possible is order to have____________?
A. low power factor
B. high power factor
C. high over load capacity
D. any of the above - Which of the following materials is used in the manufacture of resistance grids to be used in the starters of large motors ?
A. Copper
B. Aluminium
C. Steel
D. Cast-iron - Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ?
A. Increased I R losses
B. Increased core losses
C. Poor commutation
D. Change in motor parameters
E. All of the above - Which of the following in an application of D.C. motors?
A. Traction
B. Drives for process industry
C. Battery driven vehicles
D. Automatic control
E. All of the above
