Deck 7: Casting and Moulding Processes: Part A

Question 1

As the moisture content of sand increases

A)permeability remains unchanged
B)permeability decreases
C)permeability increases

Answer 1

permeability decreases

Question 2

The advantage of permanent mould casting is

A)reduced labour charges
B)reduced mould cost
C)dense, fine grained structure
D)all of the above

Answer 2

all of the above

Question 3

Which of the following holes appear on the surface of the casting when it is machined?

A)Pin holes
B)Slag holes
C)Gas holes
D)Blow holes

Answer 3

Gas holes

Question 4

Which wood can be used for making patterns?

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

Question 5

In case of malleable iron castings, the contraction allowance on pattern

A)is independent of section thickness
B)increass as the section thickness of casting increases
C)decreases as the section thickness of casting increases

Question 6

Contraction allowance for grey cast iron is (in mm/m)

A)21
B)30
C)10.5

Question 7

In case of plaster moulding the mould is prepared in

A)gypsum plaster
B)slacked lime
C)lime + cement
D)any of the above

Question 8

Which statement is not true for green sand moulding?

A)Moulds are cheapest
B)Preparation of moulds is less time consuming
C)Defect free and castings with good surface is obtained
D)none of the above

Question 9

Melting point of copper

A)1444°C
B)1576°C
C)665°C
D)1083°C

Question 10

Rough surface of casting may result from

A)high permeability of sand
B)large grain size
C)soft ramming
D)any of the above

Question 11

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

Question 12

When sulphur is to be removed from cast iron while melting the same in cupola, the flux used is

A)molasses
B)sodium carbonate with lime stone
C)zinc sulphate with lime stone
D)none of the above

Question 13

A mould cracks after drying. It indicates

A)excess of clay
B)lack of clay
C)coarse irregular grains
D)none of the above

Question 14

Moisture content of the moulding sand is commonly

A)5% - 15%
B)1% - 4%
C)2% - 8%

Question 15

Electric furnaces can usually operate upto a temperature of

A)1250°C
B)1700°C
C)2200°C
D)1000°C

Question 16

Inoculants are added to aluminium mainly for

A)grain refinement
B)directional solidification
C)purification
D)all of the above

Question 17

Permanent mould casting is also known as

A)chill casting
B)short casting
C)gravity die casting
D)slush casting

Question 18

In investment casting the pattern is made of

A)wood
B)urea formaldehyde
C)wax
D)none of the above

Question 19

Consumable patterns are made of

A)polystyrene
B)wax
C)plaster of paris
D)any of the above

Question 20

The function of riser is

A)to allow the heat of molten metal to dissipate to atmosphere
B)to provide an opening through which molten metal is poured
C)to give an indication that mould is filled
D)to supply molten metal to casting as it tends to contract during solidification

Question 21

According to Chvorinov's equation, the solidification time of castings is

A)Directly proportional to square of the volume of the casting
B)inversely proportional to the volume the casting
C)inversely proportional to square of the volume of the casting
D)directly proportional to the volume of the castings

Question 22

Swelling of castings may occur due to

A)insufficient ramming
B)rapid pouring of molten metal
C)insufficient weight on the moulds during pouring
D)any of the above

Question 23

Graphitic cast iron is

A)hard
B)non-machinable
C)low in damping capacity
D)high in compressive strength

Question 24

Shrinkage cavity in a casting may be formed due to

A)haphazard solidification of metal
B)improperly sized gating
C)high pouring temperatures
D)any of the above

Question 25

Investment casting is also known as

A)lost wax casting
B)lost pattern casting
C)hot investment casting
D)any of the above