In mercury arc rectifiers having grid, the arc can be struck between anode and cathode only when the grid attains a certain potential, this potential being known as______________?

Related Mcqs:

The efficiency of the copper oxide rectifier seldom exceeds____________?

A. 90 to 95% B. 85 to 90% C. 80 to 85% D. 65 to 75%...

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...

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...

In which of the following appUcations, direct current is absolutely essential ?

A. Illumination B. Electrolysis C. Variable speed operation D. Traction...

A synchronous converter can be started______________?

A. by means of a small auxiliary motor B. from AC. side as induction motor C. from D.C. side as D.C. motor D. any of the above methods E. none of the above methods...