| 1. | The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be ? | |
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150 V
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less than 150 V
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greater than 150 V
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none of the above
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Report Question| 2. | The main factor which leads to unstable parallel operation of flat and over compounded generators is ? | |
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their rising voltage characteristics
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unequal number of turns in their series field windings
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unequal speed regulation of their prime movers
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unequal series field resistances
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| 3. | An external resistance added in the field of a D.C. shunt generator will ? | |
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decrease the voltage of the generator
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increase the voltage of the generator
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increase the power delivered
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increase the speed of the generator
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| 4. | In a D.C. generator in case the resistance of the field winding is increased, then output voltage will ? | |
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increase
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decrease
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remain unaffected
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fluctuate heavily
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| 5. | The rapid wear of brushes takes place due to ? | |
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abrasion from dust
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excessive spring pressure
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rough commutator bars
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all of the above factors
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| 6. | The e.m.f. induced in the armature of a shunt generator is 600V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be ? | |
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640 V
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620 V
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600 V
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580 V
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| 7. | Which of the following statement about D.C. generators is false ? | |
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Compensating winding in a D.C. machine helps in commutation
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In a D. C. generator interpoles winding is connected in series with the armature winding
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Back pitch and front pitch are both odd and approximately equal to the pole pitch
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Equilizing bus bars are used with parallel running of DC shunt generators
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| 8. | Brushes of D.C. machines are made of ? | |
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carbon
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soft copper
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hard copper
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all of above
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| 9. | A separately excited generator as compared to a self-excited generator ? | |
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is amenable to better voltage control
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is more stable
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has exciting current independent of load current
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has all above features
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| 10. | In D.C. generators, the cause of rapid brush wear may be ? | |
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severe sparking
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rough commutator surface
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imperfect contact
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any of the above
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