Q $-9$ The dimentions of a cylindrical side riser $($height $=$ diameter$)$ for a $25cm15cm5cm$ steel casting are to be determined. For shape factor values $0\mathrm{.}6$ and ratio of the riser volume to casting volume of $0\mathrm{.}55,$ the diameter of the riser $($in $cm)$ is

a$)15$

c$)10,95$

b$)6$

d$)8$

Q$-11$ Riser for Sandcasting can be designed using

a$)$ All of these

c$)$ caine's method

b$)$ Naval Research laboratory method

d$)$ Modulus method.

Q$-12$ The best shape for sprue in sandcasting is

a$)$ either straight cylindrical or trapred

b$)$ Straight cylindrical

c$)$ shape will not matter

d$)$ Tapered.

Q$-13$ Hardness is the Prorerty of material due to which it$.$

a$)$ Can be rolled or hammered into thin sheets.

b$)$ will break with little permanent distortion

c$)$ Can cut another metal

d$)$ can be drawn into wires.