| 1. | Delta/star transformer works satisfactorily when ? | |
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load is balanced only
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load is unbalanced only
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on balanced as well as unbalanced loads
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none of the above
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Report Question| 2. | A no-load test is performed on a transformer to determine ? | |
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core loss
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copper loss
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efficiency
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magnetising current
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| 3. | Which winding of the transformer has less cross-sectional area ? | |
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Primary winding
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Secondary winding
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Low voltage winding
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High voltage winding
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| 4. | The secondary winding of a current transformer whose primary is carrying current should ? | |
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not be open-circuited
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not be short-circuited
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either of the above
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none of the above
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| 5. | The size of a transformer core will depend on ? | |
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frequency
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area of the core
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flux density of the core material
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(a)and (b) both
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| 6. | In a transformer the resistance between its primary and secondary should be ? | |
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zero
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10?
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1000 ?
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infinity
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| 7. | In an ideal transformer, on no-load, the primary voltage is balanced by ? | |
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the primary induced e.m.f.
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the secondary induced e.m.f
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the secondary voltage
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the drop across resistances and reactance
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| 8. | The short-circuit voltage of a transformer mainly depends on the ? | |
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magnitude of leakage flux
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ohmic resistance of primary winding
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ohmic resistance of secondary winding
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cross-sectional area of the iron core
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| 9. | The maximum load that a power transformer can carry is limited by its ? | |
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temperature rise
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dielectric strength of oil
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Voltage ratio
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copper loss
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| 10. | Distribution transformers are generally designed for maximum efficiency around ? | |
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90% load
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zero load
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25% load
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50% load
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