| 1. | In a mercury pool rectifier, the voltage drop across its electrodes ? | |
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is directly proportional to load
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is inversely proportional to load
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varies exponentially with the load current
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is almost independent of load current
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Report Question| 2. | A mercury arc rectifier possesses ...... regulation characteristics ? | |
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straight line
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curved line
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exponential
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none of the above
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| 3. | In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of ? | |
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shunt motor
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synchronous motor
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induction regulator
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synchronous generator
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| 4. | The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ? | |
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They are mechanically strong
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They-do-not require any voltage for filament heating
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Both (a) and (b)
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None of the above
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| 5. | ln mercury arc rectifiers having grid, the arc can be struck between anode and cathode only when the grid attains a certain potential, this potential being known as ? | |
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maximum grid voltage
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critical grid voltage
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any of the above
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none of the above
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| 6. | In a mercury arc rectifier ...... flow from anode to cathode ? | |
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ions
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electrons
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ions and electrons
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any of the above
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| 7. | When a rectifier is loaded which of the following voltage drops take place ? | |
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Voltage drop in transformer reactance
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Voltage drop in resistance of transformer and smoothing chokes
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Arc voltage drop
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All of the above
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| 8. | The efficiency of the copper oxide rectifier seldom exceeds ? | |
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90 to 95%
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85 to 90%
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80 to 85%
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65 to 75%
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| 9. | Copper oxide rectifier is usually designed not to operate above ? | |
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10ºC
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20ºC
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30ºC
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45ºC
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| 10. | A commutating rectifier consists of commutator driven by ? | |
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an induction motor
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a synchronous motor
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a D.C. series motor
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a D.C. shunt motor
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