In selenium rectifiers efficiencies ranging from _______ to _______ percent are attainable?

Related Mcqs:

Copper oxide rectifier is usually designed not to operate above___________?

A. 10°C B. 20°C C. 30°C D. 45°C...

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...

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...

To produce cathode spot in a mercury arc rectifier______________?

A. anode is heated B. tube is evacuated C. an auxiliary electrode is used D. low mercury vapour pressures are used...

A rotary converter is a single machine with______________?

A. one armature and one field B. two armatures and one field C. one armature and two fields D. none of the above...