| 1. | Star-star power transformer is protected by current transformer having ? | |
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star/star connections
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delta/delta connections
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star/delta connections
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delta/star connections
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View Answer
Discuss in Forum
Report Question| 2. | Most widely used insulating and cooling transformer liquid is ? | |
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mineral oil
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water
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askarel
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none of the above
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| 3. | A transformer, as compared to an amplifier, cannot increase ? | |
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the output current
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the output voltage
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the output power
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none of the above
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| 4. | Which of the following 3-phase connections of transformer create disturbances in communication systems ? | |
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star/delta
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delta/star
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star/star
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delta/delta
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| 5. | In high frequency transformer ferrite cores are used because a ferrite core has ? | |
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low resistance
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high resistance
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low permeability
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high hysteresis
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| 6. | The secondary winding of which of the following transformers is always kept closed ? | |
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Step-up transformer
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Step-down transformer
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Potential transformer
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Current transformer
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| 7. | Delta-delta power transformer is protected by current transformer having ? | |
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star/star connections
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delta/delta connections
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star/delta connections
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delta/star connections
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| 8. | ln large transformers, oil is invariably used in order to ? | |
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lubricate the core
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insulate the core
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insulate the coils
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none of the above
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| 9. | A sinusoidal e.m.f. ? | |
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leads the flux inducing it by 180º
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leads the flux inducing it by 90º
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lags the flux inducing it by 180º
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the flux inducing it by 90°
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| 10. | ln core-type transformers, the concentric windings are used with ? | |
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low voltage winding placed next to core
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low voltage winding on the outer side
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high voltage winding placed next to core
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high voltage winding on the outer side
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