| 1. | H.R.C. fuses on a transformer provide protection against ? | |
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insulation failure
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internal faults
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external faults
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low oil level
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Report Question| 2. | The place of transformer installation is selected such that ? | |
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location is not too warm
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plenty of dry and clean air is available and wet conditions are not encountered
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location is not subject to damage from men and material traffic
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all above requirements are met with
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| 3. | Which of the following can be reduced when the flux density in the transformer core is increased ? | |
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Copper losses
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Output frequency
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Size of the transformer
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None of the above
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| 4. | Which of the following statement concerning parallel operation of transformers is incorrect ? | |
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Transformers must be operated at the same frequency
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Transformers must have same transformation ratio
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Transformers must have equal kVA
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Transformers must have equal voltage ratings
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| 5. | In, measuring voltage or current by means of instrument transformer ? | |
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only ratio errors need be considered
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both ratio as well as phase angle error need to be considered
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either of the above
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none of the above
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| 6. | If a transformer core is made of copper and coils are made up of steel wire, then ? | |
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eddy current losses will be less
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copper losses in the windings will be more
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magnetising current will be reduced
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all of the above
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| 7. | The function of breather in a transformer is ? | |
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to provide oxygen inside the tank
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to cool the coils during reduced load
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to cool the transformer oil
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arrest flow of moisture when outside air enters the transformer
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| 8. | Helical coils can be used on ? | |
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low voltage side of high kVA transformers
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high frequency transformers
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high voltage side of small capacity transformers
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high voltage side of high kVA rating transformers
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| 9. | The path of the magnetic flux in transformer should have ? | |
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high reluctance
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low reactance
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high resistance
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low resistance
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| 10. | ln a given transformer for given applied voltage, losses which remain constant irrespective of load changes are ? | |
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friction and windage losses
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copper losses
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hysteresis and eddy current losses
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none of the above
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