Rectifiers And Converters Set 1

Voltage drop in transformer reactance ✘ Voltage drop in resistance of transformer and smoothing chokes ✘ Arc voltage drop ✘ All of the above ✔

aluminium ✘ silver ✘ copper ✘ graphite ✔

Copper ✘ Aluminium ✘ Zinc ✘ None of the above ✔

The rectifier will not operate ✘ Internal losses will be reduced ✘ Both ion and electron streams will move in the same direction ✘ The rectifier will operate at reduced efficiency ✔

anode is heated ✘ tube is evacuated ✘ an auxiliary electrode is used ✘ low mercury vapour pressures are used ✔

by means of a small auxiliary motor ✘ from A.C. side as induction motor ✘ from D.C. side as D.C. motor ✘ any of the above methods ✔

two ✘ three ✘ four ✘ six ✔

Copper oxide rectifiers ✘ Selenium rectifiers ✘ Mechanical rectifiers ✘ None of the above ✔

One-third of a cycle ✘ One-fourth of a cycle ✘ One-half a cycle ✘ Two-third of a cycle ✔

5 to 10 per cent ✘ 15 to 20 per cent ✘ 25 to 30 per cent ✘ none of the above ✔