A. full-load
B. rated r.p.m.
C. rated voltage
D. all of the above
Related Mcqs:
- D.C. generators are installed near the load centres to reduce_____________?
A. iron losses
B. line losses
C. sparking
D. corona losses - In case-the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be______________?
A. 100%
B. around 90%
C. anywhere between 75% and 90%
D. less than 50% - The condition for maximum efficiency for a D.C. generator is______________?
A. eddy current losses = stray losses
B. hysteresis losses = eddy current losses
C. copper losses = 0
D. variable losses = constant losses - If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor_____________?
A. of lower H.P. should be selected
B. of higher H.P. should be selected
C. can be used for 50°C ambient temperature also
D. is to be derated by a factor recommended by manufacturer and select the next higher H.P. motor - The total losses in a well designed D.C. generator of 10 kW will be nearly______________?
A. 100 W
B. 500 W
C. 1000 W
D. 1500 W - Which of the following load normally needs starting torque more than the rated torque?
A. Blowers
B. Conveyors
C. Air compressors
D. Centrifugal pumps - Which of the following method of speed control of D.C. machine will offer minimum efficiency ?
A. Voltage control method
B. Field control method
C. Armature control method
D. All above methods - In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be_____________?
A. almost negligible
B. rated full-load current
C. less than full-load current
D. more than full-load current - In D.C. motor which of the following can sustain the maximum temperature rise?
A. Slip rings
B. Commutator
C. Field winding
D. Armature winding - The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is______________?
A. 4.0
B. 2.0
C. 1.0
D. 0.5
