Deck 8: Casting and Moulding Processes: Part B

Question 1

High silicon irons are

A)resistant to wear
B)brown in colour
C)machinable
D)malleable

Answer 1

resistant to wear

Question 2

Carbondioxide moulding is useful for

A)very thin sections
B)regular sections
C)heavy and thick walled sections
D)all of the above

Answer 2

heavy and thick walled sections

Question 3

A drawback is employed when

A)the pattern is too bulky
B)the pattern is too long
C)the pattern is not made of wood
D)the pattern cannot be drawn from mould due to projection

Answer 3

the pattern cannot be drawn from mould due to projection

Question 4

In furan moulding which of the following is used as a catalyst?

A)Potassium hydroxide
B)Phosphoric acid
C)Ammonium hydroxide
D)Phenol formaldehyde

Question 5

In case of copper, the pouring temperature is around

A)1160°C
B)1060°C
C)1260°C
D)1450°C

Question 6

Polystyrene is generally available in the form of

A)trapezoidal moulds
B)square sections
C)plates
D)cylindrical bars

Question 7

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

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

Question 8

The strength of the sand is high if grains are

A)round and small
B)sharp and irregular in shape
C)large and regular in shape
D)none of the above

Question 9

A mould which has good erosion resistance to metal flow and is also collapsible is

A)green sand mould
B)skin dry sand mould
C)dry sand mould
D)none of the above

Question 10

During the passage of molten metal through the coke, the carbon percentage of the molten metal increases. The absorption of carbon depends on

A)size of the coke
B)temperature
C)time allowed for molten metal to remain in the cupola
D)all of the above

Question 11

Hot spots are generally found in castings

A)symmetrical about two axes
B)having abrupt variation in section
C)with uniform cross-section
D)small in weight but large in volume

Question 12

Which of the following metals has the lowest melting point?

A)Tin
B)Silver
C)Zinc
D)Magnesium

Question 13

Slag in a blast furnace is

A)lighter than molten iron
B)heavier than molten iron

Question 14

Sprues are generally

A)tapered upwards
B)tapered downwards
C)uniform size

Question 15

When bench moulding is adopted using three boxes, the central box is called

A)cope
B)cheek
C)drag
D)none of the above

Question 16

Cores are made from core sand mixed with the binder which may be

A)linseed oil
B)turpentine
C)cement
D)none of the above

Question 17

Thermal efficiency of cupola is in the range

A)30 to 50 percent
B)60 to 75 percent
C)50 to 65 percent
D)80 to 90 percent

Question 18

Which of the following sand must possess high refractoriness?

A)Backing sand
B)Parting sand
C)Facing sand
D)all of the above

Question 19

The rammer used for packing the sand in pockets/corners of a mould is known as

A)Floor rummer
B)Hand rammer
C)Peen rammer

Question 20

Normal shrinkage allowance for aluminium is 18 mm per metre and that for cast iron 10 mm per metrD. 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)10 mm/metre
B)28 mm/metre
C)8 mm/metre
D)18 mm/metre

Question 21

Which of the following defect is likely to occur due to improper design of gatting system?

A)Shrinkage
B)Porosity
C)Mould erosion
D)any of the above

Question 22

White cst iron contains

A)free graphite
B)cementite
C)free carbon
D)none of the above

Question 23

A slick is mainly used for

A)repairing and finishing of mould
B)removing pattern from the mould
C)making openings in mould
D)providing openings in the mould

Question 24

The cross-section of a sprue

A)square
B)circular
C)rectangular
D)any of the above

Question 25

Grey cast iron is

A)resistant to shock
B)least fluid in molten condition
C)poor in machining ability
D)costlier than other varieties of cast iron