Which of the following is used on moulds for magnesium castings to prevent metal mould reactions?
A.Boric sulphur
B.Molasses
C.Charcoal
D.all of the above
Category: Foundry Technology Mcqs
The most efficient shape of a series is that which
A.given a minimum heat loss
B.keeps the metal in molten state for longer period
C.both (A) and (B) above
Tempering is generally done to reduce all of the following EXCEPT:
A.Brittleness
B.Ductility
C.Hardness
D.Tensile strength
A casting process which can produce cylinders by inserting cores into molten metal poured in the mould is
A.Semi permanent mould casting
B.pressed casting
C.permanent mould or gravity die casting
D.none of the above
Which of the following test on castings is based on sound?
A.Impact test
B.Percussion test
C.Radiographic
D.Magnetic particle inspections
The thicker sections of casting will have a tendency to have
A.grains coarser than thinner sections
B.grains finer than thinner sections
C.grains of sme size as rest of the casting
D.none of the above
Malleable castings are used for
A.boilers
B.Automobiles
C.Elevators
D.all of the above
Which of the following statement is correct?
A.When average cost is decreasing, it is more than marginal cost
B.When average cost is decreasing, it is less than marginal cost
C.When average cost is increasing, it is more than marginal cost
D.None of the above
Which of the following cast iron is resistant to attack by sea water?
A.Low chromium cast iron
B.Low nickel cast iron
C.Low sulphur cost iron
D.Low phosphorous cast iron
All of the following are boring tools EXCEPT:
A.Gauge
B.Brace
C.Pinchdog
D.Auger bit
