Which of the following motor is preferred for operation in highly explosive atmosphere ?
A. Series motor
B. Shunt motor
C. Air motor
D. Battery operated motor
Which D.C. motor is preferred for elevators ?
A. Shunt motor
B. Series motor
C. Differential compound motor
D. Cumulative compound motor
In D.C. machines the residual magnetism is of the order of_________________?
A. 2 to 3 per cent
B. 10 to 15 per cent
C. 20 to 25 per cent
D. 50 to 75 per cent
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
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 ratio of starting torque to full-load torque is least in case of____________?
A. series motors
B. shunt motors
C. compound motors
D. none of the above
The power mentioned on the name plate of an electric motor indicates____________?
A. the power drawn in kW
B. the power drawn in kVA
C. the gross power
D. the output power available at the shaft