Hot working of lead is carried out at
75°C
373°K
150°C
Room temperature
Correct Answer :
B. 373°K
Related Questions
__________ has a negative co-efficient of linear expansion.
Iron
Copper
Rubber
Nickel
Which of the following pairs is not correctly matched?
Uranium - 233 : Fertile material
Binding energy : Mass defect
Scattering: Absorption cross-section
Number of nucleons : Mass number
Which of the following can be manufactured using powder metallurgy techniques?
Brake linings
Bearings
Carbide tool tips
All 'a', 'b' and 'c'
The unit of gc is
lbm/lbf. ft/sec2
lbf/lbm. ft/sec2
ft/sec2
lbm/lbf. sec2/ft
The substance used as a smoke screen in warfare is
C2H2
SiCl4
P2O5
PCl5
The most important function of a washer is to provide bearing area and washers are normally specified by their hole diameters. The diameter of washer as compared to the nut is
More
Less
Same
More but less than the diameter of bolt
Thermal efficiency of an internal combustion engine is around __________ percent.
8
35
65
80
Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is
Very low which prevents their ignition by compression
Very high which prevents their ignition by compression
Zero
None of these
Which of the following is an unconventional source of energy?
Thermal power
Hydroelectric power
Nuclear-fusion power
Solar power
Enzymes belong to the category of
Proteins
Carbohydrates
Vitamins
Fats
__________ circuit is most commonly used to measure strain with the help of a strain gauge.
Ballast
Voltage balancing potentiometric
Simple current sensitive
None of these
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
The pressure outside a bubble/droplet of liquid is __________ the internal pressure.
Greater than
Less than
Equal to
Unpredictable; depends on the bubble size
Which of the following metals reacts violently with water?
Mercury
Sodium
Calcium
Magnesium
Blow off cock is provided in steam boiler to
Guard the boiler in case of abnormal rise in steam pressure
Drain out water and sludge during its repair
Regulate the supply of water in boiler
Put out the fire in the furnace when the water level in the boiler falls to unsafe limit
Specific __________ is a dimensionless quantity.
Heat
Humidity
Weight
None of these
If Reynolds number is greater than 1, then the
Viscous force is larger than the inertia force
Inertia force is larger than the viscous force
Inertia force is larger than the surface tension force
Inertia force is larger than the gravitational force
In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is
1
1.4
1.5
Y = Cp/Cv
Depreciation of machines fails under the indirect expenses head. As per income tax regulations, it is calculated by the __________ method.
Diminishing balance
Sinking fund
Multiple straight line
Sum of the years digit
A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
Increase
Decrease
Remain unaffected
May increase or decrease; depends on the thickness of each layer
Nickel and __________ are the alloying element added in steel to increase its toughness.
Molybdenum
Chromium
Vanadium
Silicon
Desalination of water
Makes it potable
Makes it non-potable
Means distillation of water
None of these
Between 230 and 370°C, blue brittleness is caused in mild steel because of the
Immobility of dislocation
Strain-ageing
Increase in Young's modulus
Strain hardening
Normalising of an object does not
Refine coarse grain structure obtained during hot working
Improve ductility
Improve yield strength
Improve mechanical properties
Square steel key is normally strong in failure by shear & crushing. Keys are normally made of __________ steel bars.
Hot rolled mild
Cold rolled mild
Forged
Machinable stainless
While the bin cards are used in the effective stores management, the queuing theory is associated with the __________ time.
Waiting
Idle
Inspection
Tool replacement
Gas turbine normally employs a constant __________ cycle.
Pressure
Temperature
Volume
None of these
Gantt charts are used for streamlining the
Inventory control
Production schedule
Sales forecasting
Quality control
Out of the following substances, one ton of __________ will store the maximum heat for a rise of 30°C in temperature.
Steel
Lignite
Water
Lime stone
Fibrous fracture is normally encountered in the __________ materials.
Hard
Elastic
Ductile
Brittle