| 1. | In DC generators the polarity of the interpoles ? | |
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is the same as that of the main pole ahead
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is the same as that of the immediately preceding pole
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is opposite to that of the main pole ahead
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is neutral as these poles do not play part in generating e.m.f.
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Report Question| 2. | Armature reaction of an unsaturated D.C. machine is ? | |
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cross magnetising
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demagnetising
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magnetising
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none of above
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| 3. | If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be ? | |
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zero
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small
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the same as rated voltage
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high
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| 4. | In a D.C. generator the ripples in the direct e.m.f. generated are reduced by ? | |
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using conductor of annealed copper
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using commutator with large number of segments
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using carbon brushes of superior quality
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using equiliser rings
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| 5. | In the case of lap winding resultant pitch is ? | |
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multiplication of front and back pitches
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division of front pitch by back pitch
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sum of front and back pitches
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difference of front and back pitches
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| 6. | Wave winding is composed of ? | |
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any even number of conductors
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any odd number of conductors
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that even number which is exact multiple of poles + 2
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that even number which is exact multiple of poles
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| 7. | D.C. generator generates ? | |
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a.c. voltage in the armature
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d.c. voltage in the armature
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a.c. superimposed over d.c.
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none of the above
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| 8. | Permeance is the reciprocal of ? | |
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flux density
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reluctance
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ampere-turns
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resistance
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| 9. | Lap winding is composed of ? | |
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any even number of conductors
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any odd number of conductors
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that even number which is exact multiple of poles + 2
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that even number which is exact multiple of poles
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| 10. | Which generator cannot start if there is no residual magnetism ? | |
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Series generator
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Shunt generator
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Separately excited generator
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All of the above
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