Search
.Management Sciences
Category: Rectifiers and Converters
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
With a motor converter it is possible to obtain D.C. voltage only upto__________?
A. 200-100 V
B. 600—800 V
C. 1000—1200 V
D. 1700—2000 V
The cathdde voltage drop, in a mercury arc rectifier, is due to_____________?
A. expenditure of energy in ionization
B. surface resistance
C. expenditure of energy in overcoming the electrostatic field
D. expenditure of energy in liberating electrons from the mercury
In 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______________?
A. maximum grid voltage
B. critical grid voltage
C. any of the above
D. none of the above
The potential drop in the arc, in a mercury arc rectifier, varies_____________?
A. 0.05 V to 0.2 V per cm length of the arc
B. 0.5 V to 1.5 V per cm length of the arc
C. 2 V to 3.5 V per cm length of the arc
D. none of the above
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
In which of the following appUcations, direct current is absolutely essential ?
A. Illumination
B. Electrolysis
C. Variable speed operation
D. Traction
Recent Comments