The primary function of a riser is to

Investment casting uses ......... (wax / resin coated sand) as pattern material and is preferred for small parts with ................. (simple/intricate) designs

Investment casting uses ...... A........... as pattern material and is preferred for small parts with .......... B.........designs.

A. wax / resin coated sand
B. simple / intricate

Increase in carbon content in plain carbon steels raise its