The problem of shrinkage cavity is more likely to occur while casting ......... A ............ B.......... a chill block

(A.) metal / plastic , (B.) with / without.

In $$TIG$$ welding a ...........A. .......... and ..........B.......... electrode is used.

A. non-consumable / consumable
B. coated / bare

The mode of metal transfer in $$C{O_2}$$-$$MIG$$ welding at low temperature is