Engineering :: Foundry Technology

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11.

In copper alloy foundry which of the following is used to prevent the molten metal from being oxidized?

A.	charcoal	B.	bone ash
C.	phophorous	D.	calcium carbonate

12.

The disadvantage in using wood as the material for pattern making is

A.	its low cost	B.	its different strength along the grains and across the grains
C.	it gets warped when not stored properly	D.	it is lighter than the metal to be cast

13.

Which wood can be used for making patterns?

A.	Mathogany	B.	Pine wood
C.	Teak wood	D.	any of the above

14.

Normal shrinkage allowance for aluminium is 18 mm per metre and that for cast iron 10 mm per metre. If the metal pattern is to be made of aluminium and the casting is to be of cast iron, the shrinkage allowed on wooden master pattern will be

A.	8 mm/metre	B.	10 mm/metre
C.	18 mm/metre	D.	28 mm/metre

15.

The drawback with metallic pattern is

A.	excessive weight	B.	expensive
C.	difficult to shape	D.	all of the above

16.

Plaster patterns and core boxes are made of

A.	Plaster of Paris	B.	Gypsum cement
C.	Bone china clay	D.	White powder

17.

Phenolic thermo-setting plastics are finding application in pattern making because

A.	they do not absorb moisture	B.	they are strong
C.	they are resistant to wear	D.	they have all above qualities

18.

Wax patterns are used in

A.	non-ferrous castings	B.	investment casting process
C.	machine moulding process	D.	all of the above

19.

If an old casting is to be used as a pattern, to account for various allowances.

A.	casting is shaken while withdrawing from mould	B.	the surfaces are lagged with thin strips of wood or leater
C.	the castings are cleaned and made smooth	D.	to provide draw screws, holes can be drilled and tapped in the castings

20.

When wooden patterns with metallic coating are to be used, the metal sprayed on wooden pattern could be

A.	bismuth	B.	zinc
C.	aluminium	D.	any of the above