267. Large and heavy castings are made by
A.Green sand moulding
B.Pit moulding
C.Dry sand moulding
D.Pressure moulding
268. Graphite moulds are used for continuous casting process in order to provide
A.Non-wirig agent
B.Self lubricating qualities chilling effect
C.Heat resisting medium
D.Quick solidification of metal
269. Ferrous alloys are usually cast by
A.Hot chamber machine
B.Die casting machine
C.Direct blow machine
D.None of the above
270. The tolerances produced by the investment casting process are of the order of
A.A few microns
B.± 0.05 mm
C.± 1 mm
D.± 5 mm
271. Sweep pattern is used for moulding parts having
A.Rectangular shape
B.Elliptical shape
C.Uniform symmetrical shape
D.Complicated shape having intricate details
272. Centrifugal process is
A.Limited to symmetrical objects about horizontal axis
B.Limited to symmetrical objects about vertical axis
C.Used for producing castings of irregular shape
D.Used for producing one casting at a time
273. Drossing in foundry practice refers to
A.A method of cleaning the castings
B.An inspection method for castings
C.A method of deoxidation of molten metal
D.The formation of oxides on the molten metal surface
Page 39 of 139