Control of Electric Drives solved MCQs

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The selection of an electric motor for any application depends on which of thefollowing factors ? The selection of an electric motor for any application depends on which of thefollowing factors ? Electrical characteristics Mechanical characteristics Size and rating of motors All of the above discuss The answer is: D. All of the above
For a particular application the type of electric-and control gear are determined bywhich of the following considerations ? For a particular application the type of electric-and control gear are determined bywhich of the following considerations ? Starting torque Conditions of environment Limitation on starting current All of the above discuss The answer is: D. All of the above
Which ofthefollowingmotors is preferred for traction work ? Which ofthefollowingmotors is preferred for traction work ? Universal motor D.C. series motor Synchronous motor Three-phase induction motor discuss The answer is: B. D.C. series motor
Which of the following motors always starts on load ? Which of the following motors always starts on load ? Conveyor motor Floor mill motor Fan motor All of the above discuss The answer is: D. All of the above
is preferred for automatic drives is preferred for automatic drives. Squirrel cage induction motor Synchronous motors Ward-Leonard controlled C. motors discuss The answer is: C. Ward-Leonard controlled
When the load is above a synchronous motor is found to be more economical When the load is above a synchronous motor is found to be more economical. 2 kW 20 kW 50 kW 100 kW discuss The answer is: D. 100 kW
The load cycle for a motor driving a power press will be The load cycle for a motor driving a power press will be variable load continuous continuous but periodical intermittent and variable load discuss The answer is: D. intermittent and variable load
Light duty cranes are used in which of the following ? Light duty cranes are used in which of the following ? Power houses Pumping stations Automobile workshops All of the above discuss The answer is: D. All of the above
While selecting an electric motor for a floor mill, which electrical characteristics willbe of least significance ? While selecting an electric motor for a floor mill, which electrical characteristics willbe of least significance ? Running characteristic Starting characteristics Efficiency Braking discuss The answer is: D. Braking
Which of the following motors are pre-ferred for overhead travelling cranes ? Which of the following motors are pre-ferred for overhead travelling cranes ? Slow speed motor Continuous duty motors Short time rated motors None of the above discuss The answer is: C. Short time rated motors
is preferred for synthetic fibre mills is preferred for synthetic fibre mills. Synchronous motor Reluctance motor Series motor Shunt motor discuss The answer is: B. Reluctance motor
Ward-Leonard controlled D.C. drives are generally used for excavators Ward-Leonard controlled D.C. drives are generally used for excavators. Light duty Medium duty Heavy duty All of the above discuss The answer is: C. Heavy duty
Which of the following motors is used for elevators ? Which of the following motors is used for elevators ? Induction motor Synchronous motor Capacitor start single phase motor Any of the above discuss The answer is: A. Induction motor
Which part of a motor needs maximum attention for maintenance ? Which part of a motor needs maximum attention for maintenance ? Frame Rearing Stator winding Rotor winding discuss The answer is: B. Rearing
need frequent starting and stopping of electric motors, need frequent starting and stopping of electric motors, Paper mills Grinding mills Air-conditioners Lifts and hoists discuss The answer is: D. Lifts and hoists
Which feature, while selecting a.motor for centrifugal pump, will be of leastsignificance ? Which feature, while selecting a.motor for centrifugal pump, will be of leastsignificance ? Starting characteristics Operating speed Horse power Speed control discuss The answer is: D. Speed control
motor is a constant speed motor motor is a constant speed motor. Synchronous motor Synchronous motor Induction motor Universal motor discuss The answer is: B. Synchronous motor
The starting torque in case of centrifugal pumps is generally The starting torque in case of centrifugal pumps is generally less than running torque same as running torque slightly more than running torque double the running torque discuss The answer is: A. less than running torque
Which of the following motors are best for the rolling mills ? Which of the following motors are best for the rolling mills ? Single phase motors Squirrel cage induction motors Slip ring induction motors D.C. motors discuss The answer is: D. D.C. motors
is not a part of ball bearing ? is not a part of ball bearing ? Inner race Outer race Cage Bush discuss The answer is: D. Bush

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