For a D.C. shunt motor which of the following is incorrect?
A. Unsuitable for heavy duty starting
B. Torque varies as armature current
C. Torque armature current is a straight line
D. Torque is zero for zero armature current
Answer: Option A
A. Unsuitable for heavy duty starting
B. Torque varies as armature current
C. Torque armature current is a straight line
D. Torque is zero for zero armature current
Answer: Option A
Rotor of a motor is usually supported on _________ bearings.
A. Ball or roller
B. Needle
C. Bush
D. Thrust
When the load is above _________ a synchronous motor is found to be more economical.
A. 2 kW
B. 20 kW
C. 50 kW
D. 100 kW
For derris and winches which of the following drives can be used?
A. Pole changing squirrel cage motors
B. D.C. motors with Ward-Leonard control
C. A.C. slip ring motors with variable resistance
D. Any of the above
Which of the following motors is preferred for traction work?
A. Universal motor
B. D.C. series motor
C. Synchronous motor
D. Three-phase induction motor
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