Machinability of hard alloys and tool steels is improved by
Spheroidising
Annealing
Tempering
Normalising
Correct Answer :
B. Annealing
Related Questions
Which of the following has the highest value of refractive index?
Brine (sea water)
Diamond
Distilled water
Glass
Closeness of packing is maximum in case of __________ crystal lattice.
Face centred
Simple cubic
Body centred
None of these
Corrosion rate cannot be lowered by reducing the __________ of the corroding medium.
Concentration
Velocity
Temperature
None of these
Current employed in resistance welding ranges from __________ kVA/
.
1.2 to 2.5
4.5 to 6.2
7.5 to 8.5
10.5 to 15.5
Cobalt - 60 is used as a source of __________ in medical therapy & industrial radiography.
X-rays
γ-rays
α-rays
β-rays
Tip of the match stick contains a mixture of
K + S
K + S + K2Cr2O7
S + K2Cr2O7 + White P
None of these
Catalyst used in the catalytic converter employed in automobiles to convert CO into CO2 and for complete oxidation of un-burnt hydrocarbons is
Nickel
Cobalt
Vanadium
Platinum
Super conduction in metals is observed at a temperature of __________ °K.
<100
>100
About 273
About 373
A material being tested for endurance strength is subjected to the __________ load.
Impact
Completely reversed
Dynamic
Static & dynamic
Increase in the entropy of a system represents the
Degradation of energy
Decrease in system pressure
Increase in the availability of energy
Increase in the temperature
Brinell Hardness Number (BHN) for talc is approximately in the range of
1-5
20-30
100-150
200-250
Hydrogen can be
Used in I.C. engines as fuel
Liquefied & stored under cryogenic conditions
Produced by electrolysis of water
All (A), (B) & (C)
With increase in compression ratio, the volumetric efficiency of air compressor
Increases
Decreases
Remain same
May increase or decrease (depends on the suction pressure)
The units of the rate constant for a second order reaction are
Annealing of white cast iron produces __________ iron.
Grey
Nodular
Malleable
Spheroidal
Constituents of stellite are
Zinc, copper & nickel
Cobalt, chromium & tungsten
Zinc, aluminium & nickel
Nickel, cobalt & vanadium
According to maximum shear stress failure criterion, yielding in material occurs, when the maximum shear stress is equal to __________ times the yield stress.
0.5
2
√2
√3/2
With increase in temperature, the surface tension of water
Increases
Decreases
Remain constant
Increases linearly
Which of the following metals cannot be hot worked at room temperature?
Zinc
Nickel
Lead
Tin
Hot & cold working of material causes its __________ deformation.
Visco-elastic
Isotropic
Elastic
Plastic
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
The mechanism involved in the removal of metal in drilling operation is by
Compression
Extrusion
Shearing
Both 'b' & 'c'
In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will
Decrease gradually
Increase gradually
Increase rapidly
Remain constant
__________ furnace is generally used in the non-ferrous foundries.
Direct arc
Indirect arc
Resistance
Induction
Normalising of a casting does not
Induce stresses in it
Refine its grain structure
Reduce segregation
Improve its mechanical properties
A material subjected __________ must have high resilience.
Shock loading
Vibration
Fatigue
Tension
Brittleness induced due to the presence of sulphur in steel can be reduced by adding
Manganese
Magnesium
Vanadium
Copper
In chemical dehumidification process
Wet bulb temperature increases
Dry bulb temperature remains constant
Dew point temperature increases
Dry bulb temperature increases
The size of the tetrahedral void in the closest packing of atoms is __________ that of the octahedral void.
Equal to
Greater than
Less than
Either (A), (B) or (C); depends on the size of atom
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