| 1. | In a mercury arc rectifier, the anode is usually made of ? | |
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copper
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aluminium
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silver
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graphite
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Report Question| 2. | It is the ..... of the transformer on which the magnitude of angle of overlap depends ? | |
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resistance
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capacitance
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leakage reactance
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any of the above
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| 3. | If cathode and anode connections in a mercury arc rectifier are inter changed ? | |
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the rectifier will not operate
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internal losses will be reduced
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both ion and electron streams will move in the same direction
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the rectifier will operate at reduced efficiency
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| 4. | To produce cathode spot in a mercury arc rectifier ? | |
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anode is heated
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tube is evacuated
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an auxiliary electrode is used
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low mercury vapour pressures are used
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| 5. | In a three-phase mercury arc rectifiers each anode conducts for ? | |
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one-third of a cycle
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one-fourth of a cycle
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one-half a cycle
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two-third of a cycle
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| 6. | The internal efficiency of a mercury arc rectifier depends on ? | |
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voltage only
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current only
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voltage and current
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r.m.s. value of current
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| 7. | Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of ? | |
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100 A at 100 V
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200 A at 200 V
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300 A at 300 V
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500 A at 500 V
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| 8. | A rotary converter in general construction and design, is more or less like ? | |
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a transformer
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an induction motor
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an alternator
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any dc machine
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| 9. | A rotary converter combines the function of ? | |
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an induction motor and a D.C. generator
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a synchronous motor and a DC generator
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a D.C. series motor and a D.C. generator
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none of the above
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| 10. | In selenium rectifiers efficiencies ranging from to percent are attainable ? | |
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25, 35
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40, 50
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60, 70
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75, 85
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