| 1. | In D.C. generators, the brushes remain in contact with conductors which ? | |
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lie under south pole
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lie under north pole
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lie in the inter-polar gaps
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Bone of the above
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Report Question| 2. | Armature reaction in a generator results in ? | |
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demagnetisation of leading pole tip and magnetisation of trailing pole tip
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demagnetisation of trailing pole tip and magnetisation of leading pole tip
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dimagnetising the centre of all poles
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magnetising the centre of all poles
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| 3. | In a DC generator the number of mechanical degrees and electrical degrees will be the same when ? | |
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r.p.m. is more than 300
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r.p.m, is less than 300
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number of poles is 4
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number of poles is 2
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| 4. | The material for commutator brushes is generally ? | |
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mica
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copper
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cast iron
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carbon
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| 5. | In a D.C. generator, the armature reaction results in ? | |
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demagnetisation of the centres of poles
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magnetisation of inter poles
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demagnetisation of the leading pole tip and magnetisation of the trailing pole tip
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magnetisation of the leading tip and demagnetisation of the trailing pole tip
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| 6. | The e.m.f. generated by a shunt wound D.C. generator is E. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be ? | |
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E/2
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2E
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slightly less than E
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E
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| 7. | In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilised is called ? | |
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rotor
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stator
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field
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armature
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| 8. | ln over compounded generator, full load terminal voltage is ? | |
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almost zero
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less than no-load terminal voltage
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more than no-load terminal voltage
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equal to no-Ioad terminal voltage
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| 9. | With a D.C. generator which of the following regulation is preferred ? | |
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100% regulation
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infinite regulation
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50% regulation
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1% regulation
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| 10. | If residual magnetism of a shunt generator is destroyed accidentally, it may be restored by connecting its shunt field ? | |
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in reverse
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to a battery
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to earth
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to an alternator
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