A. Direct arc
B. Indirect arc
C. Resistance
D. Induction
Related Mcqs:
- Oxide layer formed on the non-ferrous metal surface after its annealing is__________________?
A. Removed by acid pickling
B. Hammered into the surface
C. Removed with coarse emery cloth
D. Left as such to protect the surface - _______________ is the trade name assigned to a non-ferrous cast alloy composed of cobalt, chromium & tungsten ?
A. Stellite
B. High speed steel
C. Cermet
D. Alnico - Non-ferrous alloys used for making cutting tools need not have high__________________?
A. Abrasion resistance
B. Toughness
C. Red hardness
D. Cutting speed - Transformation range for ferrous material is the temperature interval during which ___________________ is formed during its heating?
A. Cementite
B. Austenite
C. Martensite
D. Pearlite - One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is____________________?
A. 100
B. 900
C. 9000
D. 10000 - Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to___________________?
A. Achieve very high purity of aluminium (99.9%)
B. Keep the electrolyte in liquid condition by the generation of heat
C. Electrolytically dissociate alumina
D. Both B. & C. - Volume of blast furnace slag is about _______________ times the volume of hot metal (pig iron) of the same weight ?
A. 1.5
B. 3
C. 5
D. 7 - Basic open hearth furnace (BOF) is not used for producing ______________ steel?
A. Killed
B. Rimming
C. High alloy
D. None of these - Blast furnace slag is mainly molten_________________?
A. Sand
B. Magnesium silicate
C. Calcium silicate
D. Iron pyrite - Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by_________________?
A. Conduction
B. Convection
C. Radiation
D. Both A. & B.
