Cores are used to
Form internal cavities in the casting
Improve mould surface
Form a part of a green sand mould
All of these
Correct Answer :
D. All of these
Related Questions
In a four high rolling mill, there are four rolls out of which
One is working roll and three are backing up rolls
Two are working rolls and two are backing up rolls
Three are working rolls and one is backing up roll
All of the four are working rolls
Extrusion
Is extensively used for making bolts and nuts
Is used for reducing the diameter of round bars and tubes by rotating dies which open and close rapidly on the work
Is used to improve fatigue resistance of the metal by setting up compressive stresses in its surface
Consists of pressing the metal inside a chamber to force it out by high pressure through an orifice which is shaped to provide the desired form of the finished part
A jolt machine is used to
Ram the sand harder at the pattern face with decreasing hardness towards the back of the mould
Ram the sand harder at the back of the mould and softer on the pattern face
Produce uniform sand hardness throughout the mould
Produce uniform packing of sand in the mould
The flux commonly used in brazing is
Zinc chloride
Ammonium chloride
Rosin plus alcohol
Borax
The process used to improve fatigue resistance of the metal by setting up compressive stresses in its surface, is known as
Hot piercing
Extrusion
Cold peening
Cold heading
The adhesiveness is the property of sand due to which
It evolves a great amount of steam and other gases
The sand grains stick together
It clings to the sides of a moulding box
None of these
Aluminium is the best material for making patterns because it is
Light in weight
Easy to work
Corrosion resistant
All of these
The advantage of Thermit welding is that
All parts of the weld section are molten at the same time
Weld cools almost uniformly
Results in a minimum problem with internal residual stresses
All of the above
The operation of cutting a cylindrical hole in a sheet of metal by the punch and die is called
Shearing
Piercing
Punching
Blanking
Which of the following methods can be used for manufacturing 2 metre long seamless metallic tubes?
Drawing
Extrusion
Rolling
Extrusion and rolling
Seam welding is best adopted for metal thickness ranging from
0.025 to 3 mm
3 to 5 mm
5 to 8 mm
8 to 10 mm
According to Indian standards, the total numbers of tolerance grades are
8
12
18
20
In permanent mould casting method
Molten metal is poured in a metallic mould, retained in the mould long enough for the outer skin to solidify and finally mould is turned over to remove molten metal still in molten condition
Molten metal is poured and allowed to solidify while the mould is revolving
Molten metal is forced into mould under high pressure
None of the above
An oxidising process used for aluminium and magnesium articles is called
Galvanising
Anodising
Parkerising
Sherardizing
The minimum size of a bloom is
5 cm × 5 cm
10 cm × 10 cm
15 cm × 15 cm
20 cm × 20 cm
Blanking and piercing operations can be performed simultaneously in a
Simple die
Progressive die
Compound die
Combination die
Metal patterns are used for
Small castings
Large castings
Complicated castings
Large scale production of castings
The shrinkage allowance for cast iron pattern is
10 mm/m
16 mm/m
20 mm/m
26 mm/m
Thermit welding is often used in
Replacing broken gear teeth
Repairing broken shears
Joining rails, truck frames and locomotive frames etc.
All of the above
Cores are used to
Form internal cavities in the casting
Improve mould surface
Form a part of a green sand mould
All of these
The upsetting is a process of
Increasing the cross-section of a bar
Reducing the cross-section of a bar
Joining the two surfaces of metal under pressure after heating
Bending of a bar
The operation of straightening a curved sheet metal, is known as
Drawing
Squeezing
Coining
Planishing
When the dimension is expressed as 20 -0.025 ⁺⁰⁰³⁵, then the basic size is
20 mm
20.035 mm
20.025 mm
19.975 mm
The fullers are used
For finishing flat surfaces
For necking down a piece of work
For punching a hole
To finish the punched hole
In a _________, the molten metal is poured and allowed to solidify while the mould is revolving.
Die casting method
Slush casting method
Permanent mould casting method
Centrifugal casting method
Sand wash is a casting defect which
Results in a mismatching of the top and bottom parts of a casting
Results in general enlargement of the casting
Occurs near the ingates as rough lumps on the surface of a casting
Occurs as sand patches on the upper surface of a casting
Which of the following welding process uses non-consumable electrodes?
TIG welding
MIG welding
Manual arc welding
Submerged arc welding
In forehand welding, the angle between the welding rod and the work is kept as
30°-40°
40°-50°
50°-60°
60°-70°
In order to check the clearance between two mating surfaces, a ________ gauge should be used.
Ring
Plug
Feeler
None of these
In a cold chamber die casting machine
Melting pot is separate from the machine
Melting pot is an integral part of the machine
Melting pot may have any location
Low temperature and pressure is used