In Imperial Smelting Process for extraction of zinc, zinc vapour thus produced is quenched in the external condenser by the use of the following:
Jet of water at high pressure
Blast of air
Mixture of water and air
Rain of molten lead
Correct Answer :
D. Rain of molten lead
Related Questions
Water hammer is caused in steam carrying pipelines, because of
Partial condensation of steam
Vibration of the pipeline
High degree of superheat of steam
Its exposure to torrential rain
Basic open hearth furnace (BOF) is not used for producing __________ steel.
Killed
Rimming
High alloy
None of these
An approximately __________ process exemplifies the flow of a gas through a very long pipe of uniform cross-section.
Adiabatic
Isothermal
Isentropic
Isochoric
Which of the following terminology is used for the temperature at which new grains are formed in a metal?
Eutectic temperature
Lower critical temperature
Recrystallisation temperature
Upper critical temperature
Pick out the correct statement.
Hot worked materials are subjected to annealing to remove internal stresses
Annealing of steel hardens it slightly
Normalising of a material induces stresses
Tempering of a material improves ductility & toughness but reduces hardness & brittleness
Gantt charts are used for streamlining the
Inventory control
Production schedule
Sales forecasting
Quality control
Which of the following are considered applications of ultrasonic testing?
Determination of elastic constant
Detection of defects in metal
Measurement of material thickness
None of the above
The main charge in blast furnace is usually
Iron ore & coke
Iron ore, coke & air
Limestone, coke & iron ore
Limestone, sand & iron ore
Which of the following emissions in the exhaust gas of an I.C. engine causes the formation of photochemical smog?
Nitrogen oxides
Hydrocarbons
Both 'a' & 'b'
Carbon monoxide
__________ has the highest melting point out of the following.
Tungsten
Zirconium
Molybdenum
Tantalum
The material used for coating the welding electrode is termed as the
Flux
Slag
Protective layer
Binder
A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution.
Neutral
Ideal
Buffer
Zero pH
Which of the following is resistant to the action of both heat & chemicals?
Borosilicate glass
Silica glass
Soda lime glass
None of these
Vibration upto 100 kilo hertz can be most accurately measured by a __________ type accelerometer.
Preloaded spring
Piezoelectric
Bonded strain gauge
None of these
Direct conversion of thermal energy to electrical energy is facilitated by the
Fuel cells
Photo voltaic cell
Magneto hydrodynamic generator
None of these
The best guide to judge the general quality of water is the measurement of its
pH value
Electrical conductivity
Turbidity
Dissolved oxygen content
Lead is poured into the joint between two __________ pipes.
Mild steel
Concrete
Cast iron
Asbestos cement
In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the
Range is 15°F
Approach is 10°F
Both (A) & (B)
Neither (A) nor (B)
Pick out the wrong statement.
Both annealing and normalising release the internal stresses of the material besides improving the mechanical properties
Low carbon steel does not respond to the heat treatment for hardening of the material, hence it is subjected to case hardening or surface hardening processes like cyaniding, carburising, nitriding etc., which produces high carbon outer layers resulting in increase of surface hardness
Induction hardening and flame hardening techniques are also used for surface hardening
Martempering of a material is a hardening process
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
The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C.
768
1127
1359
1480
In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be
ΔQ = 0, ΔS=0
ΔQ = 0, ΔS = +ve
ΔQ = 0, ΔS = -ve
ΔQ = +ve, ΔS= +ve
Dislocations are __________ defects.
Point
Line
Volume
None of these
Electrochemical corrosion can occur, only if __________ is present in contact with metal.
Air
Oxygen
Liquid medium
Gaseous medium
With increase in compression ratio, the volumetric efficiency of air compressor
Increases
Decreases
Remain same
May increase or decrease (depends on the suction pressure)
Which of the following is not a ferromagnetic material?
Nickel
Cobalt
Aluminium
Iron
The unit of gc is
lbm/lbf. ft/sec2
lbf/lbm. ft/sec2
ft/sec2
lbm/lbf. sec2/ft
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
Minimum thermal efficiency of a steam boiler may be around __________ percent
25
45
65
20
In chemical dehumidification process
Wet bulb temperature increases
Dry bulb temperature remains constant
Dew point temperature increases
Dry bulb temperature increases