Deck 1: Foundry Processes and Materials

Question 1

Permeability of moulding sand is increased due to/by

A)Hard ramming
B)Soft ramming
C)Clay

Answer 1

Soft ramming

Question 2

In small castings which of the following allowance can be ignored?

A)Machining allowance
B)Rapping allowance
C)Draft allowance
D)Shrinkage allowance

Answer 2

Rapping allowance

Question 3

The design of gate should be such as to

A)avoid erosion of cores and mould cavity
B)prevent scum, slag and eroded sand particles from entering the mould cavity
C)minimize turbulence and dross formation
D)all of the above

Answer 3

all of the above

Question 4

Mixing coal dust with moulding sand results in

A)blackening of the mould
B)strong mould
C)good air venting
D)none of the above

Question 5

The order of dimensional accuracy in die casting is nearly

A)4 percent
B)0.4 percent
C)0.04 percent
D)0.004 percent

Question 6

Hairlines in die casted materials result from

A)chemical attack
B)mechanical erosion
C)thermal fatigue
D)all of the above

Question 7

Flux used in cupola while melting cast iron is

A)lime stone
B)coke slurry
C)molasses
D)any of the above

Question 8

Which heat treatment is applicable to aluminium alloy castings?

A)Stabilizing
B)Solution heat treatment
C)Artificial ageing
D)all of the above

Question 9

Die casting is generally not used for

A)cast iron
B)zinc base alloys
C)aluminium base alloys
D)non-ferrous metals

Question 10

The principal ingredients of moulding sands are

A)silica sand, carbon, hydrocarbons and moisture
B)silica sand, clay and water
C)silica sand, dust and crabon
D)silica sand, carbon and water

Question 11

The function of ejection pin in die casting is to

A)pushout casting off the die
B)provide movable core spaces
C)facilitate die casting of several components
D)none of the above

Question 12

Which of the following process is used for melting of steel?

A)L D process
B)Kaldo process
C)Duplex process
D)All of the above

Question 13

Slag and dross can be removed by

A)skimming from the molten metal
B)using bottom pouring ladle
C)using pouring basin in place of a pouring cup
D)any of the above

Question 14

Sand acquires a predetermined shape under pressure and retains the same when pressure is removed. This is due to the property of sand known as

A)Cohesiveness
B)Plasticity
C)Refractoriness
D)none of the above

Question 15

Refractoriness in the moulding sand is due to the presence of

A)Clay
B)Additives and Binders
C)Silica

Question 16

Heat treatment of castings is usually done for

A)refinement of grain structure
B)improving machinability
C)relieving internal stress
D)any of the above

Question 17

Average amount of sand required in a foundry for making one tonne of casting is nearly

A)2 tonnes
B)20 tonnes
C)0.1 tonne
D)0.2 tonne

Question 18

On drying, wood

A)expands
B)shrinks
C)changes colour

Question 19

Aluminium is not a very good material for die casting because

A)it is very light but strong
B)its melting point is high, it erodes the die surface and tends to react chemically with die
C)it cools much slowly
D)none of the above

Question 20

Warped castings may be produced due to

A)poor collapsibility of cores
B)non-provision of camber allowance on the pattern
C)weak flasks
D)any of the above

Question 21

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

Question 22

The purpose of clay in a moulding sand is to

A)Act as a binder in the mould
B)Make the mould refractory
C)Mak the mould permeable

Question 23

A defect in castings in which a discontinuity is formed due to the imperfect fusion of two streams of metal in the mould cavity is known as

A)scabs
B)hot tears
C)cold shut
D)drops

Question 24

Of the following metals, the pouring rate should be minimum for

A)brass
B)cast iron
C)aluminium
D)steel

Question 25

Which of the following metal can be cast in plaster moulds?

A)Yellow brass
B)Manganese
C)Aluminium bronzes
D)All of the above