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.Management Sciences
Category: Industrial Drives
For blowers which of the following motor is preferred ?
A. D.C. series motor
B. D.C. shunt motor
C. Squirrel cage induction motor
D. Wound rotor induction motor
Which of the following motors are pre-ferred for overhead travelling cranes ?
A. Slow speed motors
B. Continuous duty motors
C. Short time rated motors
D. None of the above
In series motor which of the following methods can be used for changing the flux per pole ?
A. Tapped field control
B. Diverter field control
C. Series-parallel control
D. Any of the above
A reluctance motor_________________?
A. is provided with slip rings
B. requires starting gear
C. has high cost
D. is compact
The selection of an electric motor for any application depends on which of the following factors ?
A. Electrical characteristics
B. Mechanical characteristics
C. Size and rating of motors
D. Cost
E. All of the above
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
In ______________ the speed can be varied by changing the position of brushes?
A. slip ring motor
B. schrage motor
C. induction motor
D. repulsion motor
________________is preferred for automatic drives?
A. Squirrel cage induction motor
B. Synchronous motors
C. Ward-Leonard controlled D.C. motors
D. Any of the above
For crane travel which of the following motors is normally used ?
A. Synchronous motor
B. D.C. differentially compound motor
C. Ward-Leonard controlled D.C. shunt motor
D. AC. slip ring motor
Ward-Leonard controlled D.C. drives are generally used for _____________________ excavators?
A. Light duty
B. Medium duty
C. Heavy duty
D. All of the above
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