239. Blue colour on the pattern is marked for
A.Machined surfaces
B.Never used in pattern making operation
C.Loose piece pattern
D.Surfaces to be chilled

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240. For gray cast iron, the volumetric shrinkage is of the order of
A.6%-5%
B.1.9% to negative value
C.3.5%-2.5%
D.2.5-1.9%

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241. The pouring temperature for grey cast iron is
A.1000°C
B.1250°C
C.1400°C
D.1550°C

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242. Chilled surfaces are marked on the pattern by
A.Oblique red strips
B.Yellow cross strips
C.Black cross strips on yellow
D.Oblique red strips on yellow

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243. Centrifugal method of casting is used to
A.Ensure purity and density at extremities of a casting
B.Cast symmetrical objects
C.Obtain high density and pure castings
D.Use heavy cast iron mould to act as chill

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244. A large intricate heavy casting weighing in tons is to be cast. The most appropriate moulding process would be
A.Machine moulding
B.Pit moulding
C.Cement moulding
D.Green sand moulding

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245. The patterns in the case of machine moulding are mounted on
A.Match plates
B.Moulding boards
C.Follow boards
D.Steel table

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