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.Management Sciences
Category: Rectifiers and Converters
The efficiency of the copper oxide rectifier seldom exceeds____________?
0
A. 90 to 95%
B. 85 to 90%
C. 80 to 85%
D. 65 to 75%
In a mercury arc rectifier, the anode is usually made of_____________?
A. copper
B. aluminium
C. silver
D. graphite
E. tungsten
Normally, which of the following is used, when a large-scale conversion from AC. to D.C. power is required ?
A. Motor-generator set
B. Motor converter
C. Rotary converter
D. Mercury arc rectifier
To produce cathode spot in a mercury arc rectifier______________?
A. anode is heated
B. tube is evacuated
C. an auxiliary electrode is used
D. low mercury vapour pressures are used
Which of the following metals is generally manufactured by electrolysis process ?
A. Load
B. Aluminium
C. Copper
D. Zinc
E. None of the above
In a glass bulb mercury arc rectifier the maximum current rating is restricted to___________?
A. 2000 A
B. 1500 A
C. 1000 A
D. 500 A
Which of the following is the loss within the mercury arc rectifier chamber ?
A. Voltage drop in arc
B. Voltage drop at the anode
C. Voltage drop at the cathode
D. All of the above
In a mercury arc rectifier________ flow from anode to cathode
A. ions
B. electrons
C. ions and electrons
D. any of the above
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
E. None of the above
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