| 1. | As load on an induction motor goes on increasing ? | |
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its power factor goes on decreasing
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its power factor remains constant
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its power factor goes on increasing even after full load
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its power factor goes on increasing upto full load and then it falls again
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Report Question| 2. | Slip of an induction motor is negative when ? | |
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magnetic field and rotor rotate in opposite direction
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rotor speed is less than the synchronous speed of the field and are in the same direction
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rotar speed is more than the synchronous speed of the field and are in the same direction
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none of the above
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| 3. | The speed of a squirrel-cage induction motor can be controlled by all of the following except ? | |
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changing supply frequency
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changing number of poles
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changing winding resistance
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reducing supply voltage
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| 4. | Low voltage at motor terminals is due to ? | |
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inadequate motor wiring
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purely regulated power supply
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any one of the above
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none of the above
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| 5. | The magnetising current drawn by induction motors and transformers is the cause of their ...... power factor ? | |
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leading
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lagging
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unity
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zero
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| 6. | The primary winding of a Schrage motor is located ? | |
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in stator
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lower part of rotor
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in upper part of rotor
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partly in stator and partly in rotor
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| 7. | ln a 3-phase induction motor reactance under running conditions is less than its stand still value because of decrease in ? | |
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stator magnetic flux
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mutual flux linking the stator and rotor conductor
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rotor inductance
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frequency of rotor e.m.f.
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| 8. | The principle of operation of a three phase induction motor closely resembles to that of which of the following ? | |
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Synchronous motor
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D.C. series motor
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Transformer with short-circuit secondary
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Transformer with open-circuited secondary
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| 9. | The two important parts of a 3-phase induction motor are ? | |
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rotor and armature
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rotor and stator
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slip ring and brushes
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stator and field
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| 10. | Which of the following parameters for an induction motor varies as square of the supply voltage ? | |
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Slip
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Synchronous speed
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Starting current
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Maximum running torque
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