Rectifiers

11. Copper oxide rectifier is usually designed not to operate above

1. 10°C
2. 20°C
3. 30°C
4. 45°C

View answer

12. Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of

1. 100 A at 100 V
2. 200 A at 200 V
3. 300 A at 300 V
4. 400 A at 400 V
5. 500 A at 500 V

View answer

13. If cathode and anode connections in a mercury arc rectifier are inter changed

1. the rectifier will not operate
2. internal losses will be reduced
3. both ion and electron streams will move in the same direction
4. the rectifier will operate at reduced efficiency

View answer

14. In a glass bulb mercury arc rectifier the maximum current rating is restricted to

1. 2000 A
2. 1500 A
3. 1000 A
4. 500 A

View answer

15. In a grid control of mercury arc rectifiers when the grid is made positive relative to cathode, then it the electrons on their may to anode.

1. accelerates
2. decelerates
3. any of the above
4. none of the above

View answer

16. In a mercury arc rectifier _________ flow from anode to cathode

1. ions
2. electrons
3. ions and electrons
4. any of the above

View answer

17. In a mercury arc rectifier characteristic blue luminosity is due to

1. colour of mercury
2. ionization
3. high temperature
4. electron streams

View answer

18. In a mercury arc rectifier positive ions are attracted towards

1. anode
2. cathode
3. shell bottom
4. mercury pool

View answer

19. In a mercury arc rectifier, the anode is usually made of

1. copper
2. aluminium
3. silver
4. graphite
5. tungsten

View answer

20. In a mercury pool rectifier, the voltage drop across its electrodes

1. is directly proportional to load
2. is inversely proportional to load
3. varies exponentially with the load current
4. is almost independent of load current

View answer