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

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

For the same material, powder metallurgy process is superior to casting for

Poor collapsibility of the mold leads to .......... type of casting defect in aluminium castings.

The process by which shell like castings (like toys) are made is