| 1. | The induction motors which are provided with open slot have ? | |
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more break down torque
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less break down torque
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leading power factor
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higher efficiency
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Report Question| 2. | If single phasing occurs when the motor is running, it should not be loaded beyond ? | |
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5 per cent of rated load
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20 per cent of rated load
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60 per cent of rated load
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90 per cent of rated load
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| 3. | What is the advantage of starting a slip-ring induction motor with the help of rotor resistances as compared to other methods ? | |
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The starter bas to be designed for only a very low current
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The starting current is reduced
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starting torque increases due to the rotor resistances
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The starter can be built directly into the motor
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| 4. | The most important factor in motor maintenance is to keep ? | |
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it clean and free from foreign material
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checking its insulation
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regular check on line voltage
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regular check of its lubrication
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| 5. | In a wound 3-phase induction motor, brushes should be connected to ? | |
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external D.C. excitation
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equilizing coils
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power supply
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external star-connected resistors
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| 6. | The stator of 5 H.P. induction motor is provided with ? | |
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open slots with tapered teeth
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closed slots with parallel teeth
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semi closed slots with parallel teeth
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open slots with parallel teeth
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| 7. | Regarding single-phasing of a 3-phase induction motor under running conditions which of the following statements is incorrect ? | |
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It will stop and blow the remaining fuses
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It will continue to run without damage if it is carrying half load or less
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It will stop and promptly burnt out if it is heavily overloaded
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It will try to keep running though over-heating of part of its winding if it is carrying full-load or slight over load
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| 8. | The speed of a 3-phase wound motor can be increased by ? | |
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short circuiting slip-rings
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increasing applied voltage
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decreasing applied voltage
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decreasing external resistance in the rotor circuit
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| 9. | An induction motor is identical to ? | |
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D.C. compound motor
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D.C. series motor
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synchronous motor
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asynchronous motor
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| 10. | Which is of the following data is required to draw the circle diagram for an induction motor ? | |
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Block rotor test only
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No load test only
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Block rotor test and no-load test
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Block rotor test, no-load test and stator resistance test
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