| 1. | The efficiency of an electrolytic rectifier is nearly ? | |
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80%
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70%
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60%
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40%
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Report Question| 2. | In a glass bulb mercury arc rectifier the maximum current rating is restricted to ? | |
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2000 A
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1500 A
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1000 A
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500 A
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| 3. | The ionization potential of mercury is approximately ? | |
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5.4 V
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10.4 V
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8.4 V
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16.4 V
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| 4. | With a motor converter it is possible to obtain DC voltage only upto ? | |
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200-400 V
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600-800 V
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1000-1200 V
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1700-2000 V
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| 5. | In a rotary converter armature currents are ? | |
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d.c. only
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a.c. only
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partly a.c, and partly d.c.
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all of the above
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| 6. | Which of the following A C. motors is usually used in large motor-generator· sets ? | |
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Synchronous motor
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Squirrel cage induction motor
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Slip ring induction motor
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Any of the above
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| 7. | Which of the following is reversible in action ? | |
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Motor generator set
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Motor converter
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Rotary converter
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Any of the above
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| 8. | A rotary converter operates at a ? | |
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low power factor
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high power factor
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zero power factor
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none of the above
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| 9. | In a rotary converter I2R losses as compared to a D.C. generator of the same size will be ? | |
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same
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double
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less
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three times
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