During hot working of metals
Porosity of the metal is largely eliminated
Grain structure of the metal is refined
Mechanical properties are improved due to refinement of grains
All of the above
Correct Answer :
D. All of the above
Related Questions
A basic shaft is one whose
Lower deviation is zero
Upper deviation is zero
Lower and upper deviations are zero
None of these
The process extensively used for making bolts and nuts is
Hot piercing
Extrusion
Cold peening
Cold heading
In submerged arc welding, an arc is produced between a
Carbon electrode and the work
Metal electrode and the work
Bare metal electrode and the work
Two tungsten electrodes and the work
The welding set up is said to have straight polarity, when
Work is connected to the positive terminal and the electrode holder to the negative terminal
Work is connected to the negative terminal and the electrode holder to the positive terminal
Work is connected to the positive terminal and the electrode holder is earthed
Work is connected to the negative terminal and the electrode holder is earthed
In welding copper alloys with TIG arc welding
Direct current with straight polarity is used
Direct current with reversed polarity is used
Alternating current is used
Any one of these
In backhand welding, the angle between the welding torch and the work is kept as
30°-40°
40°-50°
50°-60°
60°-70°
Seam welding is a
Continuous spot welding process
Multi-spot welding process
Arc welding process
Process used for joining round bars
Which of the following statement is wrong?
The angular clearance on dies varies from 0.5° to 1°
In drawing operation, the metal flows due to plasticity
In press operation, the size of the pierced hole is independent of the size of punch
None of the above
The oxyacetylene gas used in gas welding produce a flame temperature of
1800°C
2100°C
2400°C
3200°C
Green sand is a mixture of
30% sand and 70% clay
50% sand and 50% clay
70% sand and 30% clay
90% sand and 10% clay
During hot working of metals
Poor surface finish is produced
Scale is formed on the metal surface
Close tolerances cannot be maintained
All of these
During hot working of metals
Porosity of the metal is largely eliminated
Grain structure of the metal is refined
Mechanical properties are improved due to refinement of grains
All of the above
The dowels are
Wooden nails
Box nails
Wire nails
None of these
The operation of straightening a curved sheet metal, is known as
Drawing
Squeezing
Coining
Planishing
A zinc diffusion process is called
Galvanising
Anodising
Parkerising
Sherardizing
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 cross-section of a chisel is usually
Rectangular
Square
Hexagonal
Octagonal
Which of the following statement is wrong?
The mortise gauge has two scribing pins
The gouges are chisels with a hollow shaped blade
An auger is a planing tool
All of these
Which of the following statement is wrong?
The hot chamber die casting machine is used for casting zinc, tin, lead and other low melting alloys.
The cold chamber die casting machine is used for casting aluminium, magnesium, copper base alloys and other high melting alloys.
The castings produced by centrifugal casting method have open and coarse grained structure.
All of the above
In a hot chamber die casting machine
Ferrous alloys with low melting temperature are casted
Ferrous alloys with high melting temperature are casted
Nonferrous alloys with low melting temperature are casted
Nonferrous alloys with high melting temperature are casted
The operation of cutting a cylindrical hole in a sheet of metal by the punch and die is called
Shearing
Piercing
Punching
Blanking
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
The instrument used to measure external and internal diameter of shafts, thickness of parts and depth of holes, is
Outside micrometer
Inside micrometer
Depth gauge micrometer
Vernier caliper
In spot welding, the distance between the nearest edge of the plate and centre of weld should be equal to
d
1.5d
3d
6d
In a gas welding of mild steel using an oxyacetylene flame, the total amount of acetylene consumed is 10 litres. The oxygen consumption from the cylinder is
5 litres
10 litres
15 litres
20 litres
In welding magnesium with TIG arc welding, direct current with _________ is used.
Straight polarity
Reversed polarity
Both (A) and (B)
None of these
In average work, the tolerance produced by investment casting method is
±0.05 mm
+0.2 mm
+05 mm
+1 mm
A pattern maker's shrinkage rule considers
All pattern allowances
Only shrinkage allowance
All materials to be cast
All materials of the pattern
A basic hole is one whose
Lower deviation is zero
Upper deviation is zero
Lower and upper deviations are zero
None of these
The temperature of oxy-hydrogen flame is _________ oxyacetylene flame.
Same as
Less than
More than
None of these