vii) Sulphide inclusion is steel may be modified by

(a) Ca-Si injection

(b) CaF₂ injection

(c) Iron ore fines injection

(d) Injection of passivated Mg granules

viii) Oxygen lance nozzles are made of

(a) Copper

(b) Ceramic materials

(c) Same type of steel as that of lance

(d) Graphite

ix) Circulation degassing of liquid steel is carried in

(a) VAD refining process

(b) VOD refining process

(c) RH process

(d) Stream degassing process

x) Complete deoxidation of liquid steel in necessary for the production of

(a) Killed steel

(b) Semi-killed steel

(c) rimming steels

(d) Capped steels

xi) In a Fe-Cr-C system, the temperature for preferential decarburization during oxygen lancing is lowered by\

(a) A reduction in the partial pressure of CO

(b) On increasing the partial pressure of CO

(c) An increase in the Cr content in the bath

(d) Decrease in the Cr content in the bath

Xii) Minimum segregation occurs in an ingot of

(a) Rimming steel

(b) Semikilled steel

(c) Killed steel

(d) None of the above

xiii) Dephophorization is favoured by

(a) High temperature and  a basic oxidizing slag

(b) Low temperature and  a basic oxidizing slag

(c) Low temperature and  an acidic oxidizing slag

(d) Low temperature and  a reducing basic slag