Industrial Drivers

11. For a motor-generator set which of the following motors will be preferred?

1. Synchronous motor
2. Slip ring induction motor
3. Pole changing induction motor
4. Squirrel cage induction motor

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12. For a particular application the type of electric-and control gear are determined by which of the following considerations?

1. Starting torque
2. Conditions of environment
3. Limitation on starting current
4. All of the above
5. All of the above

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13. For blowers which of the following motor is preferred?

1. D.C. series motor
2. D.C. shunt motor
3. Squirrel cage induction motor
4. Wound rotor induction motor

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14. For crane travel which of the following motors is normally used?

1. Synchronous motor
2. D.C. differentially compound motor
3. Ward-Leonard controlled D.C. shunt motor
4. AC. slip ring motor

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15. For derries and winches which of the following drives can be used?

1. Pole changing squirrel cage motors
2. D.C. motors with Ward-leonard con-trol
3. A.C. slip ring motors with variable resistance
4. Any of the above

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16. For which of the following applications D.C. motors are still preferred?

1. High efficiency operation
2. Reversibility
3. Variable speed drive
4. High starting torque

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17. For which of the following applications motor has to start with high acceleration?

1. Oil expeller
2. Floor mill
3. Lifts and hoists
4. Centrifugal pump

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18. has least range of speed control.

1. Slip ring induction motor
2. Synchronous motor
3. D.C. shunt motor
4. Schrage motor

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19. has relatively wider range of speed control.

1. Synchronous motor
2. Ship ring induction motor
3. Squirrel cage induction motor
4. D.C. shunt motor

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20. has the least value of starting torque to full load torque ratio.

1. D.C. shunt motor
2. D.C. series motor
3. Squirrel cage induction motor
4. Slip ring induction motor

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