| 1. | What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero ? | |
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The slip of the motor will be 5%
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The rotor will not run
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The rotor will run at very high speed
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The torque produced will be very large
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Report Question| 2. | For starting a Schrage motor, 3-phase supply is connected to ? | |
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rotor via slip rings
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regulating windings
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secondary winding via brushes
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stator as in an ordinary induction motor
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| 3. | The shaft, on which the rotor of an induction motor is mounted is made of ? | |
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high speed steel
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chrome vanadium steel
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cast-iron
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mild steel
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| 4. | The reactance per phase as compared to the resistance per phase of an induction motor is ? | |
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very small
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quite high
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almost same
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slightly large
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| 5. | Which of the following is not determined by circle diagram ? | |
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Efficiency
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Power factor
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frequency
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Output
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| 6. | What is the advantage of the slip ring induction motor ovei the squirrel cage induction motor ? | |
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It has a higher power factor
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It can be started with the help of rotor resistances
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It is suitable for higher speeds
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It can be started with the help of rotor resistances
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| 7. | In three-phase induction motors sometimes copper bars are placed deep in the rotor to ? | |
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improve starting torque
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reduce copper losses
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improve efficiency
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improve power factor
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| 8. | Under which method of starting an induction motor is expected to take largest starting current ? | |
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Star-delta starting
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Auto-transformer starting
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Direct on line starting
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Stator-rotor starting
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| 9. | Which of the following motors are used frequently ? | |
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Three phase induction motor
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DC shunt motor
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Three phase commutator motor
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AC. induction motor
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| 10. | The starting torque of the slip ring induction motor can be increased by ? | |
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adding resistance to the stator
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adding resistance to the rotor
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adding resistance to stator as well as the rotor
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none of the above
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