To produce cathode spot in a mercury arc rectifier tube is evacuated anode is heated an auxiliary electrode is used low mercury vapour pressures are used TRUE ANSWER : ? YOUR ANSWER : ?
When a rectifier is loaded which of the following voltage drops take place ? Voltage drop in transformer reactance Voltage drop in resistance of transformer and smoothing chokes All of the listed here Arc voltage drop TRUE ANSWER : ? YOUR ANSWER : ?
A rotary converter is a single machine with one armature and one field one armature and two fields two armatures and one field none of the listed here TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following methods may be used to convert A.C. system to D.C.? Rotary converters Motor converters Rectifiers All of the listed here TRUE ANSWER : ? YOUR ANSWER : ?
In which of the following applications, direct current is absolutely essential ? Illumination Traction Variable speed operation Electrolysis TRUE ANSWER : ? YOUR ANSWER : ?
On which of the following factors the number of phases for which a rectifier should be designed depends? In the output circuit there should be no harmonics All of the listed here The voltage regulation of the rectifier should be low The power factor of the system should be high TRUE ANSWER : ? YOUR ANSWER : ?
In a mercury arc rectifier______ flow from anode to cathode All of the listed here ions ions and electrons electrons TRUE ANSWER : ? YOUR ANSWER : ?
In a three-phase mercury arc rectifiers each anode conducts for One-fourth of a cycle One-third of a cycle One-half a cycle Two-third of a cycle TRUE ANSWER : ? YOUR ANSWER : ?
In selenium rectifiers efficiencies ranging from ______ to ______ percent are attainable 30, 60 40, 50 20, 30 75, 85 TRUE ANSWER : ? YOUR ANSWER : ?
In a single phase rotary converter the number of slip rings will be Four Two Six Three TRUE ANSWER : ? YOUR ANSWER : ?