A. Add alloying elements
B. Prevent electrode from contamination
C. Stabilise the arc
D. Provide protective atmosphere to weld
Related Mcqs:
- Projection welding & stud welding is categorised as the _______________ welding?
A. Pressure
B. Thermit
C. Resistance
D. Arc - In TIG welding, thoriated tungsten electrodes are used, because it ____________________?
A. Has higher current carrying capacity
B. Has better electron emissivity
C. Is stronger than ordinary tungsten
D. Is easy to prepare - Consumable electrodes are used in the ____________________ welding?
A. Gas
B. Arc
C. Thermit
D. Resistance - Thermit welding is categorised as the ______________________ welding ?
A. Forge
B. Fusion
C. Resistance
D. Arc - Which of the following mainly decides the current to be employed is arc welding ?
A. Electrode size
B. Plate thickness
C. Voltage across the arc
D. Welded portion length - Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of _______________ gms of zinc per m2 of steel strip ?
A. 5-10
B. 1000-1500
C. 120-500
D. 1500-3000 - Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process ?
A. Galvanising
B. Tinning
C. Sherardizing
D. None of these - _____________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C ?
A. Veneering
B. Galvanising
C. Electroplating
D. Calorising - Pick out the wrong statement about coating/electroplating of metals ?
A. Phosphate coating is used as an excellent base for paints & enamels
B. Phosphate coating is less corrosion resistant than chromate coating
C. The base metal to be electroplated is normally made the cathode of the electrolytic cell and
coating metal is made the anode
D. Calorising is the process of coating steel with chromium - Oxyacetylene reducing flame is used while carrying out welding on__________________?
A. Alloy steel
B. Grey cast iron
C. Mild steel
D. High carbon steel
