Thermit, used in Thermit welding, is a mixture of
Charcoal and iron oxide
Charcoal and aluminium
Iron oxide and aluminium
Charcoal, iron oxide and aluminium
Correct Answer :
C. Iron oxide and aluminium
Related Questions
Loam 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
The recrystallisation temperature of steel is
400°C
600°C
800°C
None of these
Shift is a casting defect which
Results in a mismatching of the top and bottom parts of a casting
Results in general enlargement of a 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
For arc welding
Alternating current with high frequency is used
Alternating current with low frequency is used
Direct current is used
Any one of these
In arc welding, the temperature of heat produced by the electric arc is of the order of
3000°C to 4000°C
4000°C to 5000°C
5000°C to 6000°C
6000°C to 7000°C
The property of sand due to which the sand grains stick together is called
Collapsibility
Permeability
Cohesiveness
Adhesiveness
The brass and bronze are welded by _________ flame.
Neutral
Oxidising
Carburising
All of these
The temperature of the inner luminous cone of neutral flame is about
1000°C
1250°C
2100°C
3200°C
The operation of bending a sheet of metal along a curved axis, is known as
Plunging
Notching
Slitting
Forming
Metal patterns are used for
Small castings
Large castings
Complicated castings
Large scale production of castings
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
When filing soft metals, the file teeth are clogged with minute particles of metal. The file should be cleaned by
Washing it with water
Rubbing on wood
Washing it with dilute acid
Using file card
A hacksaw blade is specified by its
Length
Material
Width
Number of teeth
The maximum flame temperature occurs
At the outer cone
At the inner cone
Between the outer and inner cone
At the torch tip
The operation of cutting a sheet of metal in a straight line along the length, is known as
Plunging
Notching
Slitting
Forming
The tolerance produced by shell moulding process of casting is
+0.05 mm
±0.2 mm
+0.5 mm
±1 mm
Carburising flame is used to weld
Steel, cast iron, copper, aluminium etc
Brass and bronze
Hard surfacing materials such as stellite
All of these
In welding magnesium with TIG arc welding, direct current with _________ is used.
Straight polarity
Reversed polarity
Both (A) and (B)
None of these
Thermit, used in Thermit welding, is a mixture of
Charcoal and iron oxide
Charcoal and aluminium
Iron oxide and aluminium
Charcoal, iron oxide and aluminium
The process of increasing the cross-section of a bar at the expense of its length, is called
Drawing down
Upsetting
Spinning
Peening
The temperature produced by oxy-hydrogen flame is about
1800°C
2100°C
2400°C
3200°C
The type of file used for a wood work is
Single cut file
Double cut file
Rasp cut file
Any one of these
A hacksaw blade cuts on the
Forward stroke
Return stroke
Both forward and return strokes
Cutting depends upon the direction of force
The cold working of metals is carried out
At the recrystallisation temperature
Below the recrystallisation temperature
Above the recrystallisation temperature
At any temperature
The welding process used to join the ends of two pipes of uniform cross-section, is
Spot welding
Seam welding
Projection welding
Upset butt welding
A basic shaft is one whose
Lower deviation is zero
Upper deviation is zero
Lower and upper deviations are zero
None of these
In a compound die
Only one operation is performed at each stroke of the ram
Two or more operations are performed simultaneously at the single stroke of the ram
Two or more cutting operations are performed at one station of the press in every stroke of the ram
Both cutting and non-cutting operations are performed at one station of the press in every stroke of the ram
A neutral flame is obtained by supplying
Equal volumes of oxygen and acetylene
More volume of oxygen and less volume of acetylene
More volume of acetylene and less volume of oxygen
None of the above
The cross-section of a chisel is usually
Rectangular
Square
Hexagonal
Octagonal
The oxygen cylinder is usually painted with
Black colour
White colour
Maroon colour
Yellow colour