In extrusion of metals, which of the following statement is true?
Speed of the extruded material is same as that of ram speed
Redundant work is a function of the die angle
Relative motion between the billet surface and the container wall is always present
Hollow ram is used for indirect extrusion
Correct Answer :
D. Hollow ram is used for indirect extrusion
Related Questions
Diameter of the rivet to be provided on a 20 mm. thick boiler plate will be __________ mm.
10
20
30
40
The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system
Is as light as possible
Has very high C.O.P.
Employs minimum quantity of refrigerant
Consumer minimum horse power
A pycnometer is used for the measurement of
Flow rate of molten metal
Specific gravity of a liquid
Composition of alloys
Concentration of a solution
Production of a hollow product by inflation of a tube or parison is called the __________ process.
Blow moulding
Calendaring
Extrusion
Injection
Lead is poured into the joints between two __________ pipes.
Cast iron
Steel
Concrete
Plastic
Sub zero treatment of steel is done to
Suppress martensite transformation
Enhance its working performance in sub zero atmosphere
Reduce the retained austenite in hardened steel
Induce temper brittleness after its hardening
Inertial forces are obtained, when the elastic forces are multiplied by __________ number.
Mach
Froude
Reynolds
Euler
What is the percentage of chromium in 18-4-1 high speed steel?
1
4
18
23
__________ property of steel increases by addition of large amount of silicon in it.
Mechanical
Machining
Magnetic
Refractory
__________ the exhaust gas is an indication of the incomplete combustion of fuel.
Low temperature of
High temperature of
High % of CO in
High % of CO2 in
Dowtherm is a
High temperature heating medium (a petroleum product)
Product of coal tar distillation
Very heat sensitive material
None of these
With increase in temperature, the electrical conductivity of semiconductors
Increases
Decreases
Remain constant
Either (A) or (B), depends on the type of semi-conductor
Electrochemical corrosion can occur, only if __________ is present in contact with metal.
Air
Oxygen
Liquid medium
Gaseous medium
Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by
Conduction
Convection
Radiation
Both 'a' & 'b'
The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability?
Lead
Copper
Aluminium
Wrought iron
Pick out the wrong statement.
Weldability of high carbon steel is poorer compared to low carbon steel
Invar is a magnetic alloy
Magnetic permeability of the diamagnetic material is less than one
Martenistic transformation never goes to completion (i.e., 100%) at room temperature
For a first order chemical reaction, the concentration of the reactant decreases __________ with time.
Linearly
Exponentially
Logarithmically
Inversely
The difference in one unit of Rockwell hardness number corresponds to a difference in the depth of indentation of __________ mm.
0.001
0.01
0.002
0.02
Oxide layer formed on the non-ferrous metal surface after its annealing is
Removed by acid pickling
Hammered into the surface
Removed with coarse emery cloth
Left as such to protect the surface
In practice, the compression ratio of compression-ignition (CI) engine ranges from
15 to 25
5 to 10
40 to 55
60 to 70
A highly elastic material is deformed least on loading and retains its original form on removal of the load. Which of the following is the most elastic material?
Steel
Glass
Rubber
Brass
Minimum number of members required to form a Public Limited Joint Stock Com-pany is
7
10
12
17
Particle nature of cathode rays is proved due to the fact that they
Travel in a straight line
Get deflected by magnetic electric field
Produce fluorescence
Heat the exposed material
Addition of silicon to cast iron
Promotes graphite module formation
Improves its ductility
Does not promote graphite flakes formation
Increases the fluidity of molten metal
Hooke's law
Applies to elastic deformation
Applies beyond limit of proportionality in stress-strain curve
States that stress is inversely proportional to strain upto elastic limit
None of these
Fire refining process is employed in case of
Tin
Copper
Zinc
Aluminium
The value of 
for air & most common gases can be safely assumed to be
0.8
1
1.4
1.8
Runge-Kutta method is used to solve a/an
Ordinary differential equation of nth order
Simultaneous non-linear equation
Linear differential equation
None of these
Hot extrusion process is not used for making
Cast iron pipe for domestic water supply
Aluminium curtain rods
Stainless steel tubes used in furnitures
Any of these
Stresses encountered in the metal forming processes are less than the __________ of the material.
Fracture strength
Yield strength
Elastic limit
Limit of proportionality