Limestone is added in the blast furnace (during pig iron manufacture) to
Form slag by combining with impurities
Supply heat by undergoing exothermic reaction with impurities
Reduce the coke consumption
Reduce slag viscosity
Correct Answer :
A. Form slag by combining with impurities
Related Questions
Faraday's law of electrolysis is related to the
Cation speed
Atomic number of the cation
Equivalent mass of the electrolyte
None of these
Temperature profile along the length of a gasgas counter flow heat exchanger is correctly represented by
at 1173E; at equilibrium, what will be the number of moles of CO gas required to reduce one mole of 
at 1173 K?
1.0
1.3
2.3
3.3
Wavelength of radiation emitted by a body depends on the __________ of its surface.
Temperature
Area
Nature
All 'a', 'b' & 'c'
The refrigerant freon-12 is chemically
CCl2F2
CCl3F
CClF3
CCl4F
Which of the following forces does not act on a fluid at rest?
Viscous force
Gravity force
Hydrostatic force
Surface tension force
The materials which fracture even at small strains are termed as brittle, while those materials which exhibit an appreciable deformation before failure are termed as
Rigid
Tough
Ductile
Plastic
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
__________ metal is used as a bearing liner material.
Pewter
White
Babbitt
Gun
Which of the following is not used as a bearing material?
Copper-lead alloys
Babbitts
Bronzes
Cermets
Starting friction is low in case of the __________ lubrication.
Boundary
Hydrodynamic
Hydrostatic
Mixed/semi-fluid
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal
Tensile strength
Compressive strength
Young's modulus
Thermal co-efficient of expansion
Out of the following the refractive index is the highest for
Glass
Diamond
Brine
Kerosene
Shaft/rotor speed is most accurately measured by a
Frequency counter
Tachometer
Strobometer
Speedometer
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)
A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
370
340
320
300
Yield strength of a polycrystalline metal with an average grain size d, is proportional to
d1/2
d-1/2
d
d-1
The value of 
for air & most common gases can be safely assumed to be
0.8
1
1.4
1.8
The activity co-efficient of the solute in a dilute solution
Decreases with the increase of concentration of the solute
Increases with the increase of concentration of the solute
Remains constant
Is unity at infinite dilution
Spark plug is provided in a/an
Engine having carburettor
Diesel engine
Compression ignition engine
Both (B) & (C)
A pycnometer is used for the measurement of
Flow rate of molten metal
Specific gravity of a liquid
Composition of alloys
Concentration of a solution
The best lubricants for a machine working at high temperature & load is
Grease
Solid lubricant
Animal oils
Mineral oils
LVDT used for displacement measurement is a/an __________ transducer.
Passive
Active
Capacitive
None of these
Batch process is preferred over continuous process, when the
Product yields and quality cannot be achieved in continuous process, because of long residence time
Sales demand of product is not steady
Same equipment cannot be used for several processes of the same nature
All (A), (B) & (C)
A solar cell converts the sunlight directly into __________ energy.
Thermal
Electrical
Mechanical
Chemical
Pick out the wrong statement.
Lead can creep under its own weight at room temperature
The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
Recrystallisation temperature decreases with decrease in strain in a cold worked metal
With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
The elastic strain in copper is due to the
Motion of dislocations
Stretching of atomic bonds
Breakage of atomic bonds
None of the above
Cementite is in the lamellar form in the __________ phase of steel.
Martenistic
Bainitic
Pearlitic
Ferritic
A particle is settling in a liquid under Stokesian conditions. The free falling velocity of the particle is proportional to
√(Particle diameter)
Particle diameter
(Particle diameter)2
(Particle diameter)3