| 1. | According to Fleming's right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., fore finger will point in the direction of ? | |
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motion of conductor
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lines of force
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either of the above
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none of the above
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Report Question| 2. | The resistance of armature winding depends on ? | |
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length of conductor
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cross-sectional area of the conductor
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number of conductors
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all of the above
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| 3. | Laminations of core are generally made of ? | |
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case iron
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carbon
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silicon steel
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stainless steel
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| 4. | ln lap winding, the number of brushes is always ? | |
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double the number of poles
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same as the number of poles
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half the number of poles
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two
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| 5. | Iron losses in a D.C. machine are independent of variations in ? | |
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speed
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load
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voltage
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speed and voltage
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| 6. | Which of the following statements is incorrect in D.C. shunt generators about hysteresis loss ? | |
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It is independent of lamination thickness
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It can be minimize by laminating the armature
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It depends upon the supply frequency
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None of the above
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| 7. | ln a four-pole D.C. machine ? | |
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all the four poles are north poles
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alternate poles are north and south
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all the four poles are south poles
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two north poles follow two south poles
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| 8. | Fleming's right-band rule regarding direction of induced e.m.f., correlates ? | |
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magnetic flux, direction of current flow and resultant force
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magnetic flux, direction of motion and the direction of e.m.f. induced
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magnetic field strength, induced voltage and current
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magnetic flux, direction of force and direction of motion of conductor
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| 9. | For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ? | |
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Lap winding
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Wave winding
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Either of (a) and (b) above
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Depends on other features of design
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| 10. | In case of D.C. machines, mechanical losses are primary function of ? | |
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current
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voltage
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speed
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none of above
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