Electrometallurgical methods of metal extraction is normally used for those metals
Whose oxide/ore is not reduced by carbon
Which fall in the category of alkali & alkaline earth metals
Which stands higher in the electrochemical series of the metal
All (A), (B) & (C)
Correct Answer :
D. All (A), (B) & (C)
Related Questions
Which of the following is the most wear resistant grade of carbide used for the cutting tools?
Aluminium carbide
Tungsten carbide
Nickel carbide
Iron carbide
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
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
Fibrous fracture is normally encountered in the __________ materials.
Hard
Elastic
Ductile
Brittle
Pick out the wrong statement.
The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S
For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire diameter)
Crushing load or columns is less than the buckling load
Modulus of resilience is proportional to (stress at elastic limit)2
Superheating of steam is done at constant
Enthalpy
Entropy
Pressure
Volume
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
The best lubricants for a machine working at high temperature & load is
Grease
Solid lubricant
Animal oils
Mineral oils
Speisses is a mixture of the following:
Arsenides of heavy metals
Antimonides of heavy metals
Arsenides & antimonides of heavy metals
Iron, cobalt and nickel
Venturimeter is used to measure the flow rate of fluids in pipes, when the pipe is in __________ position.
Horizontal
Vertical
Inclined
Any
Most important property of steels for use in automobile bodies is the
Formability
Yield strength
Toughness
Resilience
Which of the following is the most suitable abrasive for grinding high tensile strength materials?
Silicon carbide
Corundum
Aluminium oxide
Boron carbide
Chromium molybdenum steel cannot be welded using __________ welding.
Thermit
Electrical resistance
Oxy-acetylene
Any of these
Which of the following fastening devices has its both ends threaded?
Bolt
Stud
Set screw
Split nut
Air-petrol ratio in an automotive petrol engine is around
14 : 1
22 : 1
25 : 1
4 : 1
Which of the following is not used as a bearing material?
Copper-lead alloys
Babbitts
Bronzes
Cermets
In chemical dehumidification process
Wet bulb temperature increases
Dry bulb temperature remains constant
Dew point temperature increases
Dry bulb temperature increases
Dryness fraction of dry steam is
0
∞
1
0.5
Joule-Thomson co-efficient is the ratio of
Pressure change to temperature change occuring during adiabatic compression of a gas
Pressure change to temperature change occuring during adiabatic throttling of a gas
Temperature change to pressure change occuring during adiabatic compression of a gas
Temperature change to pressure change occuring during adiabatic throttling of a gas
__________ fluid force is not considered in the Navier-Stokes equation.
Turbulent
Viscous
Gravity
Pressure
Maximum consumption of limestone is in the __________ industry.
Iron and steel
Cement
Glass
Fertiliser
Which of the following alloying elements is present in maximum percentage in high speed steel?
Molybdenum
Chromium
Tungsten
Vanadium
The surface tension of a liquid, at critical temperature is
Indeterminate
Zero
Infinity
Same as that at any other temperature
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
'Amortization' in respect of financial obligation of a company means the
Liquidation of financial obligations on instalment basis
Commitment of financial obligation on priority
Liquidation of all the obsolete equipments of the company
Modernisation of the plant equipments
Normalising does not __________ of a metal.
Improve machinability & tensile strength
Remove internal stresses
Refine the structure
Remove strains caused by cold working
Eutectoid composition of carbon steel at room temperature is
Cementite
Pearlite
Martensite
Ferrite
The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the
Work hardening
Bauschinger effect
Creeping effect
Stress recovery effect
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
Ammonia gas can be dried by
PCl5
Quick lime
CaCl2
Concentrated H2SO4