197. During pudding
A. molten metal is kept clear of the fuel
B. carbon is converted into carbonic acid gas
C. silicon forms a slag
D. all the above.
198. Brittleness of cold is due to an excess of
A. sulphur
B. carbon
C. phosphorus
D. silicon.
199. Red short iron cracks when bent due to the presence of
A. sulphur
B. carbon
C. phosphorus
D. silicon.
200. Pick up the correct statement from the following :
A. Air bubbles in casting produce a dull sound by tapping their surfaces lightly with a hammer
B. Cupola furnace is used for the manufacture of cast iron
C. Red short iron is of no value for welding purpose
D. All the above.
201. The process of decarbonising the pig iron -completely and then adding proper percentage of carbon for manufacturing steel, is called
A. Cementation process
B. crucible process
C. Bessemer process
D. Open hearth process.
202. The process of manufacturing steel by heating short lengths of wrought iron bars mixed with charcoal in fire clay crucibles and collecting the molten iron into moulds, is known as
A. Cementation process
B. Crucible process
C. Bessemer process
D. Open hearth process.
203. Bessemer process is used for the manufacture of
A. Pig iron
B. cast iron
C. Wrought iron
D.
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