Pick out the wrong statement.
Cold cracking of a weld is due to the presence of hydrogen gas in the weld
True stress is given by, σ = σE (1 + εE), where σE and εE are engineering stress and engineering strain respectively
Phosphorous can be easily recovered in the iron blast furnace
High residual stress at the surface is beneficial for fatigue properties of a material
Correct Answer :
C. Phosphorous can be easily recovered in the iron blast furnace
Related Questions
Stellite is a __________ material.
Ferrous
Ceramic
Cemented carbide
Non-ferrous cast alloy cutting tool
The taper provided on pattern for its easy & clean withdrawal from the mould is termed as the __________ allowance.
Casting
Pattern
Draft
Distortion
Young's modulus of a material is the measure of its
Stiffness
Malleability
Creep resistance
Tensile strength
Mild steel has __________ crystal lattice structure.
Face centred cubic (fcc)
Body centred cubic (bcc)
Orthorhombic
Cubic
Pressure required to increase the density of water by about 1% is __________ atmosphere.
10
50
200
1000
Brass parts with high residual tensile stress at the surface are susceptible to season cracking (i.e. spontaneous cracking occuring on exposure to atmospheric corrosion), if its zinc percentage is more than
5
10
20
35
There are one octahedral void and __________ tetrahedral void in the closest packing of atoms.
One
Two
Three
None of these
Optical activity is a/an __________ property.
Additive
Constitutive
Both (A) & (B)
Neither (A) nor (B)
Which of the following heat treatment processes is usually applied to castings?
Tempering
Annealing
Normalising
Carburising
The most suitable material of construction for a sewer to carry sewage under high pressure is
Asbestos cement
Steel
Cement concrete
Stoneware
The function of neutral flux used in the pyrometallurgy of metal extraction is to increase the __________ of the slag.
Fluidity
Basicity
Acidity
Viscosity
During sensible heating of humid air
Relative humidity increases
Dew point remains constant
Dry bulb & wet bulb temperature increases
Both 'b' & 'c'
The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be
Parabolic
Hyperbolic
Straight line
None of these
The only suitable method for hardening the low carbon steel is case hardening. Which of the following is a case hardening process?
Cyaniding
Sherardizing
Spheroidising
None of these
Basic open hearth furnace (BOF) is not used for producing __________ steel.
Killed
Rimming
High alloy
None of these
Which of the following is not categorised as the ore agglomeration process?
Nodulising
Pelletising
Balling
Briquetting
Saturated steam at a pressure of 25 kg/cm2 is throttled to attain 5 kg/cm2. Then the outcoming steam will be
Wet
Saturated
Superheated
None of these
Cascade control is
The continuous adjustment of the set point index of an automatic control loop by a primary (master) controller
Used when changes in process conditions cause serious upsets in the controlled variable
Useful to control flow from temperature
All 'a', 'b' & 'c'
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
For the Stoke's law to be valid in the case of a falling sphere in a fluid, the
Reynolds number (based on sphere diameter) should be < 1
Flow around the sphere should be in turbulent region
Sphere must be metallic
Fluid density should be constant
The dew point of moist air becomes __________ with decrease in its relative humidity.
Less than the wet bulb temperature
More than the wet bulb temperature
More than the dry bulb temperature
Equal to wet bulb temperature
Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal.
Burning
Intensive oxidation
Evaporation
None of these
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
Change in volume of metals from absolute zero temperature to their melting points is
Almost same for all metals
Different for different metals
Less for low melting point metals
Less for high melting point metals
Silicon percentage in silicon steel used for electrical equipments is about
1
4.0
8
14
Which of the following does not discharge the dust collected as a dry solid?
Electrostatic precipitator
Wet scrubber
Bag filter
Gravity settling chamber
On being hit with a hammer, __________ will readily fracture.
Brass
Mild steel
Cast iron
Lead
In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that
Compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller
Maintaining vacuum on tube side is more difficult than that on the shell side
Water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam
Condenser can act as a storage unit for condensed steam
In connection with corrosion of metals, passivation is the process that
Intensifies deterioration
Changes the composition of the metal
Inhibits further deterioration
None of these
Cemented carbide tools are not suitable for cutting
Aluminium
Brass
Cast iron
Steel