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.Management Sciences
Category: Rectifiers and Converters
The advantage of mercury arc rectifier is that________________?
A. it is light in weight and occupies small floor space
B. it has high efficiency
C. it has high overload capacity
D. it is comparatively noiseless
E. all of the above
Which of the following are the applications of D.C. system ?
A. Battery charging work
B. Arc welding
C. Electrolytic and electro-chemical processes
D. Arc lamps for search lights
E. All of the above
In a mercury arc rectifier positive ions are attracted towards______________?
A. anode
B. cathode
C. shell bottom
D. mercury pool
A rotary converter combines the function of____________?
A. an induction motor and a D.C. generator
B. a synchronous motor and a D.C. generator
C. a D.C. series motor and a D.C. generator
D. none of the above
Which of the following is reversible in action ?
A. Motor generator set
B. Motor converter
C. Rotary converter
D. Any of the above
E. None of the above
Copper oxide rectifier is usually designed not to operate above___________?
A. 10°C
B. 20°C
C. 30°C
D. 45°C
A commutating rectifier consists of commutator driven by___________?
A. an induction motor
B. a synchronous motor
C. a D.C. series motor
D. a D.C. shunt motor
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
In a three-phase mercury arc rectifiers each anode conducts for____________?
A. one-third of a cycle
B. one-fourth of a cycle
C. one-half a cycle
D. two-third of a cycle
Ageing of a selenium rectifier may change the output voltage by__________?
A. 5 to 10 per cent
B. 15 to 20 per cent
C. 25 to 30 per cent
D. none of the above
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