Practice Test: Question Set - 03
1. In a mercury pool rectifier, the voltage drop across its electrodes
- (A) Is directly proportional to load
- (B) Is inversely proportional to load
- (C) Varies exponentially with the load current
- (D) Is almost independent of load current
2. In phase-shift control method the control is carried out by varying the of grid voltage.
- (A) Magnitude
- (B) Polarity
- (C) Phase
- (D) Any of the above
3. Which of the following rectifiers have been used extensively in supplying direct current for electroplating?
- (A) Copper oxide rectifiers
- (B) Selenium rectifiers
- (C) Mercury arc rectifiers
- (D) Mechanical rectifiers
4. In a mercury arc rectifier, the anode is usually made of
- (A) Copper
- (B) Aluminium
- (C) Silver
- (D) Graphite
5. Which of the following methods may be used to convert A.C. system to D.C.?
- (A) Rectifiers
- (B) Motor converters
- (C) Motor-generator sets
- (D) All of the above
6. A rotary converter in general construction and design, is more or less like
- (A) A transformer
- (B) An induction motor
- (C) An alternator
- (D) Any D.C. machine
7. Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of
- (A) 100 A at 100 V
- (B) 200 A at 200 V
- (C) 300 A at 300 V
- (D) 500 A at 500 V
8. In a mercury arc rectifier characteristic blue luminosity is due to
- (A) Color of mercury
- (B) Ionization
- (C) High temperature
- (D) Electron streams
9. It is the _________of the transformer on which the magnitude of angle of overlap depends.
- (A) Resistance
- (B) Capacitance
- (C) Leakage reactance
- (D) Any of the above
10. The applications of selenium rectifiers are usually limited to potential of
- (A) 10 V
- (B) 30 V
- (C) 60 V
- (D) 100 V
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