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.Management Sciences
Category: Rectifiers and Converters
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. 400 A at 400 V
E. 500 A at 500 V
If cathode and anode connections in a mercury arc rectifier are inter changed_____________?
A. the rectifier will not operate
B. internal losses will be reduced
C. both ion and electron streams will move in the same direction
D. the rectifier will operate at reduced efficiency
The voltage drop at anode, in a mercury arc rectifier is due to_____________?
A. self restoring property of mercury
B. high ionization potential
C. energy spent in overcoming the electrostatic field
D. high temperature inside the rectifier
The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ?
A. They are mechanically strong
B. They do not require any voltage for filament heating
C. Both (A) and (B)
D. None of the above
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. Rotary converters
E. All of the above
Which of the following AC. motors is usually used in large motor-generator sets?
A. Synchronous motor
B. Squirrel cage induction motor
C. Slip ring induction motor
D. Any of the above
On which of the following factors the number of phases for which a rectifier should be designed depend ?
A. The voltage regulation of the rec¬tifier should be low
B. In the output circuit there should be no harmonics
C. The power factor of the system should be high
D. The rectifier supply transformer should be utilized to the best ad-vantage
E. all of the above
In a rotary converter I2R losses as compared to a D.C. generator of the same size will be___________?
A. same
B. less
C. double
D. three times
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