| 1. | Primary winding of a transformer ? | |
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is always a low voltage winding
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is always a high voltage winding
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could either be a low voltage or high voltage winding
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could either be a low voltage or high voltage winding
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Report Question| 2. | In a transformer the resistance between its primary and secondary is ? | |
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zero
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1 ohm
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1000 ohms
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infinite
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| 3. | Which of the following properties is not necessarily desirable for the material for transformer core ? | |
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Low hysteresis loss
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High permeability
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High thermal conductivity
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Adequate mechanical strength
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| 4. | The full-load copper loss of a transformer is 1600W. At half-load, the copper loss will be ? | |
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6400 W
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1600 W
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800 W
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400 W
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| 5. | Which of the following protection is normally not provided on small distribution transformers ? | |
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Overfluxing protection
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Buchholz relay
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Overcurrent protection
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All of the above
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| 6. | Which of the following parts of a transformer is visible from outside ? | |
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Bushings
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Core
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Primary winding
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Secondary winding
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| 7. | Part of the transformer which is most subject to damage from over heating is ? | |
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iron core
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copper winding
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winding insulation
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frame or case
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| 8. | Harmonic currents in a transformer cause ? | |
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increased core lost
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increased I2R loss
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magnetic interference with protective relays
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all of the above
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| 9. | Which of the following test on a transformer provides information about regulation, efficiency and heating under load conditions ? | |
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Back to back test
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Short circuit test
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Swinburne's test
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Open circuit test
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| 10. | Which of the following methods is used for cooling of transformers upto a capacity of 10 MVA ? | |
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Air blast cooling
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Forced oil cooling
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Oil natural cooling
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None of the above
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