| 1. | In a transformer electric power is transferred from one coil to the other coil in a transformer ? | |
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magnetically
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electromagnetically
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physically
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electrically
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Report Question| 2. | During short-circuit test iron losses are negligible because ? | |
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the current on secondary side is negligible
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the voltage on secondary side does not vary
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the voltage applied on primary side is low
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full-load current is not supplied to the transformer
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| 3. | The leakage flux in a transformer depends upon ? | |
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load current
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load current and voltage
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load current, voltage and frequency
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load current, voltage, frequency and power factor
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| 4. | The no load current in a transformer lags behind the applied voltage by an angle of about ? | |
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180º
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120º
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90º
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75º
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| 5. | Which of the following does not change in a transformer ? | |
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Current
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Voltage
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Frequency
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All of the above
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| 6. | The thickness of laminations used in a transformer is usually ? | |
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0.4 mm to 0.5 mm
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4 mm to 5mm
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14 mm to 15mm
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25 mm to 40 mm
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| 7. | Which of the following loss in a transformer is zero even at full load ? | |
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Core loss
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Friction loss
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Eddy current loss
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Hysteresis loss
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| 8. | The efficiency of a transformer, under heavy loads, is comparatively low because ? | |
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copper loss becomes high in proportion to the output
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iron loss is increased considerably
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voltage drop both in primary and secondary becomes large
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secondary output is much less as compared to primary input
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| 9. | In some transformers, the tappings are provided on ? | |
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L.V. side
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H.V. side
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L.V. as well as on H.V. side
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in the middle of both windings
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| 10. | The colour of fresh dielectric oil for a transformer is ? | |
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dark brown
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white to grey
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pale yellow
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colourless
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