A. Motor-generator set
B. Motor converter
C. Rotary converter
D. Mercury arc rectifier
0
A rotary converter operates at a______________?
0
In a rotary converter armature currents are______________?
A. low power factor
B. high power factor
C. zero power factor
D. none of the above
0
In which of the following appUcations, direct current is absolutely essential ?
A. d.c. only
B. a.c. only
C. partly a.c. and partly d.c.
0
In a mercury arc rectifier positive ions are attracted towards______________?
A. Illumination
B. Electrolysis
C. Variable speed operation
D. Traction
0
In which of the following equipment direct current is needed ?
A. anode
B. cathode
C. shell bottom
D. mercury pool
0
Which of the following AC. motors is usually used in large motor-generator sets?
A. Telephones
B. Relays
C. Time switches
D. All of the above
0
In a rotary converter I2R losses as compared to a D.C. generator of the same size will be___________?
A. Synchronous motor
B. Squirrel cage induction motor
C. Slip ring induction motor
D. Any of the above
0
The potential drop in the arc, in a mercury arc rectifier, varies_____________?
A. same
B. less
C. double
D. three times
0
Mercury, in arc rectifiers, is chosen for cathode because________________?
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
Download App