ChE basics Flashcards
Which one of the following is incombustible ?
H2
CCl4
C2H2
S
CCl4
The softness or hardness of a grinding wheel depends upon the type & amount of bonding material used. For general purpose cutter grinding __________ grinding wheel is normally used.
aluminium oxide
Tin based white metals are used, where bearings are subjected to
high pressure & load.
low pressure & load.
high temperature.
large surface wear.
high pressure & load
Friction factor for fluid flow in pipe does not depend upon the
pipe length.
pipe roughness.
fluid density & viscosity.
mass flow rate of fluid.
pipe length
All of the following alloying elements of steel increases hardness but sacrifice ductility, except
nickel
vanadium
molybdenum
chromium
nickel
The following type of bonding is strongly directional in solids.
Vander Waal’s
Ionic
Metallic
Covalant
Covalant
Fog is an example of colloidal system of
solid dispersed in gas.
solid dispersed in liquid.
liquid dispersed in gas.
gas dispersed in liquid.
liquid dispersed in gas
Chromium molybdenum steel can not be welded using __________ welding.
thermit
electrical resistance
oxy-acetylene
any of these
Electrical Resistance
Speisses is a mixture of the following:
Arsenides of heavy metals.
Antimonides of heavy metals.
Arsenides & antimonides of heavy metals.
Iron, cobalt and nickel.
Arsenides of heavy metals
Auto collimator is used to check
flatness
angle
rotor balancing
roughness
angle
In troposphere (the weather domain), the temperature ‘t’ at height ‘h’ above the sea level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)
t = 15 - 0.0065 h
t = 15 + 0.0065 h
t = 0.0035 h - 15
t = 15 - 0.0035 h
t = 15 - 0.0065 h
A high pressure boiler generates steam at a pressure greater than __________ kg/cm2 .
10
30
50
80
80
Evaporative cooling process employs a combination of cooling and humidification in which the
sensible heat is added.
sensible heat is removed and the latent heat is added.
latent heat is removed.
sensible heat is added and latent heat is removed.
sensible heat is removed and the latent heat is added.
Which of the following is not an explosive ?
TNT
CMC
RDX
Lead azide
CMC
Maxwell’s thermodynamic relations applies to the
chemical systems in equilibrium.
mechanical systems in equilibrium.
irreversible thermodynamic processes.
reversible thermodynamic processes.
chemical systems in equilibrium.
Annealing ofwhite cast iron produces __________ iron.
grey
nodular
malleable
spheroidal
malleable
Resistance of an electrical conductor is proportional to its (where, l = length and A = cross-sectional area of the conductor)
A
l
A2
both ‘a’ & ‘b’
both ‘a’ & ‘b’
A solar cell converts the sunlight directly into __________ energy.
thermal
electrical
mechanical
chemical
electrical
If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor.
critical
breeder
fertile
heterogenous
breeder
Wrought iron is never shaped by
casting
cold working
forging
welding
casting
Powder metallurgy process does not make metal powder by
atomisation
grinding/milling
hammering
electrolytic deposition
hammering
In the blast furnace, incorporation of water vapour in the blast gives the following effect.
Increases the reducing potential of the gas.
Increases the flame temperature.
No significant change occurs.
Increases the hydrogen content in the metal.
Increases the reducing potential of the gas.
Pick out the wrong statement.
A ferromagnetic material becomes paramagnetic above the ‘Curie temperature’.
Permanent magnets are made of hard materials, whereas electromagnets require soft magnetic materials.
Soft magnetic materials (e.g., pure iron) have higher permeability and low hysterisis loss and coercive forces.
Tungsten steel and alnico are not hard magnetic materials.
Tungsten steel and alnico are not hard magnetic materials.
The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel.
60 - 100
400 - 700
1200 -1500
2000 - 2300
400 - 700
Maximum permissible air velocity in pipelines is about __________ metre/second.
5
10
20
40
10
Area under the stress-strain curve upto the __________ is referred to as the modulus of resilience.
yield strength
elastic limit
proportional limit
maximum point
proportional limit
__________ is the hardest oxide and is hence used where high wear resistance at high temperature is required.
Beryllia
Zirconia
Alumina
Magnesia
Alumina
Titanium alloys are welded using the Following process:
TIG welding.
Submerged arc welding.
Butt welding.
Electron beam welding.
TIG welding.
An alloy of Fe - 0.4 % C is
cast iron.
hypo-eutectoid steel.
hyper-eutectoid steel.
eutectoid steel
hypo-eutectoid steel.
A material in which the atoms are arranged regularly in some directions but not in others, is termed as ‘mesomorphous material’; an example of which is
lead
glass
mica
silver
lead
In extrusion of metals, which of the following statement is true ?
speed of the extruded material is same as that of ram speed.
Redundant work is a function of the die angle.
Relative motion between the billet surface and the container wall is always present.
Hollow ram is used for indirect extrusion.
Hollow ram is used for indirect extrusion.
Nuclear fission of one atom of uranium-235 produces the energy equivalent to about __________ MeV.
20
200
500
1000
200
Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans ?
Emissivity of pipe surface.
Diameter & length of the pipe.
Temperature of hot pipe surface & that of air in the room.
none of these.
none of these
Machinability of hard alloys and tool steels is improved by
spherodising
annealing
tempering
normalising
annealing
Transformation range for ferrous material is the temperature interval during which __________ is formed during its heating.
cementite
austenite
martensite
pearlite
austenite
Maximum amount of thermal radiation is emitted at all wavelengths at any specified temperature by a/an __________ body.
grey
black
opaque
white
grey
In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that
A. compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller.
B. maintaining vacuum on tube side is more difficult than that on the shell side.
C. water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam.
D. condenser can act as a storage unit for condensed steam.
C. water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam.
Cobalt - 60 is used as a source of __________ in medical therapy & industrial radiography.
X-rays
γ-rays
α-rays
β-rays
γ-rays
Absolute zero pressure can be attained at a temperature of
0°C
50°K
0°R
none of these
0°R
The product out from a cupola is called
wrought iron
pig iron
cast iron
none of these
cast iron
Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as
Gr0.25, Gr
Gr0.25, Gr0.33
Gr, Gr0.25
Gr0.33, Gr0.25
Gr0.25, Gr
If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity
is trebled.
remains unchanged.
decreases by a factor of 3.
decreases by a factor of 1/3.
remains unchanged.
Copper deposits are found in India at the following location:
Kudremukh
Kolar
Khetri
Ramagundam
Khetri
Electrical conductivities of semi-conductors are of the order of __________ ohm/cm.
10-3
103
10-15
l015
10-3
Corrosion of metals can not be prevented by its
tempering
chromising
aluminising
alloying
tempering
Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of
Grashoff number.
Grashoff number & Reynolds number.
Reynolds number.
Grashoff number & Prandtl number.
Grashoff number & Prandtl number.
The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be
parabolic
hyperbolic
straight line
none of these
parabolic
Energy of the sun arises mainly from __________ reactions.
fusion
fission
combustion
none of these
fusion
Which of the following fastening devices has a head at one end and a nut fitted to the other ?
Bolt
Stud
Top bolt
None of these
Stud
Sudden fall of atmospheric pressure by a large amount is an indication of the
rain
cold wave
storm
fair weather
storm
In chemical dehumidification process
wet bulb temperature increases.
dry bulb temperature remains constant.
dew point temperature increases.
dry bulb temperature increases.
dry bulb temperature remains constant
Secondary hardening in steels arises out of the
precipitation of fine alloy carbides at high temperatures.
refinement of ferrite grain size by working.
decomposition of retained austenite upon heat treatment.
precipitation of complex inter-metal-lics upon heat treatment.
decomposition of retained austenite upon heat treatment.
Drills are usually made of
cermets
high speed steel
alloy steel
tungsten carbide
high speed steel
Tumbling is the process of improving the __________ of the materials/parts.
surface finish
fatigue limit
creep limit
surface cleanlineses
surface cleanlineses
The __________ of a double acting reciprocating pump as compared to the single acting pump will be almost double.
flow output
head developed
overall efficiency
weight
flow output
__________ of air does not increase with increase in temperature.
Density
Thermal diffusivity
Viscosity
Thermal conductivity
Density
Spherical shape of mercury droplets is due to its
high viscosity.
low surface tension.
high density.
high surface tension.
high surface tension.
Sub zero treatment of steel is done to
suppress martensite transformation.
enhance its working performance in sub zero atmosphere.
reduce the retained austenite in hardened steel.
induce temper brittleness after its hardening.
reduce the retained austenite in hardened steel.
Air-petrol ratio for maximum power generation in spark ignition engine is about
6:1
12 : 1
18 : 1
24 : 1
12 : 1
Which of the following varies as the square root of oil pressure during atomisation of fuel oil through a pressure jet burner ?
Output & fineness
Velocity
Both (a) & (b)
None of these
Both (a) & (b)
The most suitable material of construction for a sewer to carry sewage under high pressure is
asbestos cement
steel
cement concrete
stoneware
steel
Filler material used in welding should have __________ as compared to the parent metal to be welded.
lower melting temperature
same melting temperature
same composition
both ‘b’ & ‘c’
both ‘b’ & ‘c’
Oxygen cylinders used for autogenous (cutting/welding) purposes are
seamless & made of steel.
heat treated before use.
made by sand casting.
welded steel cylinders.
seamless & made of steel.
Identify the correct statement.
Sphlerite is zinc oxide.
The first law of the thermodynamics is stated as δE = δQ - δW.
Lead can be produced in a blast furnace.
T. ferrooxidans is a fungus that can be used for leaching chalcopyrite.
Lead can be produced in a blast furnace.
Dowtherm is a
high temperature heating medium (a petroleum product).
product of coal tar distillation.
very heat sensitive material.
none of these.
high temperature heating medium (a petroleum product).
To counteract the bad effects of strain hardening on a cold formed part, it must be
tempered
normalised
annealed
hardened
annealed
The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then
wet bulb temperature=dry bulb temperature.
wet bulb temperature=dew point temperature.
saturation temperature=dew point temperature.
all ‘a’ , ‘b’ & ‘c’
all ‘a’ , ‘b’ & ‘c’
Galvanic corrosion can not be prevented by
cathodic protection.
anodic protection.
usage of largest possible anodic area.
any one of these.
anodic protection.
Fire in fuel gas pipelines is extinguished most effectively by
spraying water.
blanketting the area with nitrogen atmosphere.
fire fighting foam.
none of these.
blanketting the area with nitrogen atmosphere.
Which of the following is the most suitable abrasive for grinding high tensile strength materials ?
Silicon carbide
Corundum
Aluminium oxide
Boron carbide
Aluminium oxide
Case hardening is not done by
nitriding
hot dipping
electroplating
both b & c
both b & c
Satellites burn off during re-entry to earth’s atmosphere, because of the
combustion with air.
gravitational pull by earth.
friction with earth’s atmosphere.
loss in weight of the satellite.
friction with earth’s atmosphere.
With increase in compression ratio, the volumetric efficiency of air compressor
increases.
decreases.
remains same.
may increase or decrease (depends on the suction pressure).
increases.
Neutrons are present in all atoms except that of
He
C
H
Ar
H
Biological shield in a nuclear reactor is generally provided to protect against the
α-rays
β-rays
gamma rays & neutrons
electrons
gamma rays & neutrons
__________ 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
Voltage balancing potentiometric
Which of the following is normally not found in both the S.I. (petrol) & C.I. (diesel) engines ?
Air filter
Fuel injector
Exhaust silencer
Battery
Fuel injector
__________ is a special constituent of chlorophyll without which photosynthesis is not possible.
Calcium
Nitrogen
Phosphorous
Hydrogen
Nitrogen
__________ is used as a material of construction for the blade of power saw.
Wrought iron
Stainless steel
Mild steel
High speed steel
High speed steel
During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to
time
square root of time
square of time
cube of time
square root of time
Laser welding is widely employed in the __________ industries.
electronic
structural
process
heavy
electronic
Dryness factor of steam is defined as the ratio of the mass of vapor in the mixture to the mass of the mixture. Dryness factor of steam is measured by a __________ calorimeter.
bomb
throttling
Junker’s
Boy’s
throttling
Which of the following is used to produce draught in the locomotive boilers ?
Chimney.
Induced draught fan.
Forced draught fan.
Steam jet arrangement.
Steam jet arrangement.
Temper brittleness of a material can be fairly detected by the __________ test.
fatigue
notched bar impact
tensile
hardness
notched bar impact
When the wavelength of incident X-rays increases, the angle of diffraction
decreases.
increases.
remains constant.
shows no systematic variation.
decreases.
The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is
more
equal
less
double
more
The specific gravity of coal depends mainly on its __________ content.
carbon
volatile matter
ash
moisture
moisture
In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
more
less
equal
much more
equal
Normalising does not __________ of a metal.
improve machinability & tensile strength
remove internal stresses
refine the structure
remove strains caused by cold working
remove internal stresses
Which of the following hardness tests does not measure the indentation hardness of metals and alloys ?
Vicker’s hardness test.
Shore sceleroscope test.
Brinell hardness test.
Rockwell hardness test.
Shore sceleroscope test.
With increase in annealing temperature, the following defect density decreases.
Vacancy
Dislocation
Grain boundary
All of them
All of them
Carnot cycle is also termed as the constant __________ cycle in thermodynamics.
entropy
pressure
volume
heat
heat
Thermistors are used in __________ devices.
voltage measuring
temperature measuring
temperature compensating
both (b) & (c)
both (b) & (c)
Broaching tools are usually made of
cermets
high speed steel
tungsten carbide
stellite
high speed steel
The ratio of the shear stress to the principal stress on a principal plane is
0
1
1/2
1/3
0
Minimum safe distance between two liquid fuel storage tanks is equal to (where, H = height of the tank)
H
H/2
H/4
H/6
H/6
Propulsion of rocket follows from the
Newton’s second law of motion.
Newton’s third law of motion.
law of projectiles.
Archimedes principle.
Newton’s third law of motion.
In multipass welds, shot peening is done after each pass to
close the surface porosity.
break the continuity of columnar grains.
flatten the weldment.
introduce texture in the weld.
close the surface porosity.
Pick out the correct statement.
A. Materials exhibiting high elasticity obey Hooke’s law.
B. The elastic behaviour of rubber under compression is the same as its behaviour under tension.
C. The damping capacity of a material is due to its plastic deformation.
D. The stress required to cause plastic flow in polycrystalline material is higher as compared to monocrystalline materials due to the presence of grains of different orientations.
The elastic behaviour of rubber under compression is the same as its behaviour under tension.
Consider the equilibrium A(g) + B(g) = AB(g). When the partial pressure of A is 10-2 atm, the partial pressure of B is 10-3 atm and the partial pressure of AB is 1 atm, the equilibrium constant ‘K’ is
10 atm-1
105 atm-1
10 (dimensionless)
105 (dimensionless)
105 atm-1
In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet ?
Zirconia
Alumina
Bakelite
Tungsten carbide
Tungsten carbide
Enzymes belong to the category of
proteins
carbohydrates
vitamins
fats
proteins
What is the value of included angle of a triangular notch for maximum discharge ?
30°
60°
90°
120°
90°
For separating small pieces of metal from engine oil of a car, the best separating technique is the
chromatography
evaporation
filtration
fractional distillation
filtration
Heat flow across a hollow sphere of inner radius ‘r1’ and outer radius ‘r2’ is directly proportional to
(r2-r1)/(r1r2)
(r1r2)/(r2-r1)
(r1+r2)/(r1r2)
(r1r2)/(r1+r2)
(r1*r2)/(r2-r1)
On oscilloscope screen for dynamic measurement, lissajous diagram is normally used to determine the __________ of the input signal.
frequency
amplitude
damping
none of these
frequency
Fire refining process is employed in case of
tin
copper
zinc
aluminium
copper
Larger length & diameter water pipes are made by
electrical resistance welding.
die casting.
semi-centrifugal casting.
continuous casting.
semi-centrifugal casting.
Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of
90% tungsten carbide and 10% cobalt.
70% aluminium oxide & 30% silica.
30% nickel, 15% chromium & 55% tungsten.
65% tungsten & 35% zirconium.
90% tungsten carbide and 10% cobalt
The temperature at which ferromagnetic material can no longer be magnetised by the outside forces, is termed as the
critical point.
curie temperature.
inversion temperature.
eutectic temperature.
curie temperature.
Baffles provided on the shell side of a shell and tube heat exchanger are meant for
providing support for the tubes.
improving heat transfer.
both ‘a’ & ‘b’.
preventing the fouling of tubes & stagnation of shell side fluid.
both ‘a’ & ‘b’.
When an isolated thermodynamic system executes a process,
work is done.
heat transfer takes place.
mass flow occurs across the boundary of the system.
no chemical reaction takes place within the system.
no chemical reaction takes place within the system.
Brittleness induced due to the presence of sulphur in steel can be reduced by adding
manganese
magnesium
vanadium
copper
manganese
Atomic __________ of an element is a whole number.
weight
number
volume
radius
number
The boiling & freezing points on a newly defined temperature scale in degree ‘D’ are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to __________ °D.
140
180
240
280
280
Which of the following is an unconventional source of energy ?
Thermal power
Hydroelectric power
Nuclear-fusion power
Solar power
Solar power
The product (s) of roasting of a sulphide ore is (are)
oxide only.
sulphate only.
oxide and sulphate.
dependent on temperature and partial pressure of oxygen & sulphur dioxide.
oxide only.
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.
Detection of defects in metal.
Suitability of steel for its use in cable is judged by its strength in
tension
compression
torsion
shear
tension
Hydrogen in liquid steels is dissolved
as tiny gas bubbles.
in the atomic form.
in the ionic form.
in the molecular form
as tiny gas bubbles
__________ iron is produced by the annealing of white cast iron.
Malleable
Nodular
Ductile
Grey
Malleable
The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the
final control element.
on-off control.
floating control action.
none of these.
final control element.
Fahrenheit and Centigrade scales have the same readings at
-55°
-40°
-33°
-58°
-40°
Which of the following low melting alloy containing bismuth and lead is used for electric fuse ?
Wood’s metal
Babbit metal
Monel metal
Duralumin
Wood’s metal
Water-tube boiler is the one, in which
water passes through tubes and flue gases around it.
tube carrying hot flue gases are immersed in a pool of water.
tubes are placed in vertical position.
none of these.
water passes through tubes and flue gases around it.
Dephosphorisation of molten pig iron is favoured by
oxidising and basic slag.
reducing and basic slag.
high activity co-efficient of phosphorous in metal.
oxidising and neutral slag.
reducing and basic slag.
In a neutral solution
H+ ions are absent.
OH- ions are absent.
both H+ and OH- ions are present in very small but equal concentration.
none of these.
both H+ and OH- ions are present in very small but equal concentration.
Which of the following commonly used condenser tube materials has the lowest thermal conductivity?
Admirability brass.
Stainless steel.
Aluminium brass.
Titanium.
Stainless steel
Strain hardening effect in a metal subjected to cold working is due to the __________ mechanism.
fracture
dislocation
slip
twinning
slip
A common disinfectant used in village wells for disinfection of water is
free chlorine
bromine
iodine
potassium permanganate
potassium permanganate
Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs?
enthalpy
relative humidity
wet bulb temperature
dew point temperature
dew point temperature
Which of the following metals can not be hot worked at room temperature ?
Zinc
Nickel
Lead
Tin
Nickel
Primary designation of steel is based on its
hardness & tensile strength.
carbon content.
iron content.
alloying elements content.
alloying elements content.
Steel containing low percentage of nickel, chromium & tungsten are termed as the __________ steel.
wrought
tool
alloy
plain carbon
plain carbon
Superheating of steam is done at constant
enthalpy
entropy
pressure
volume
pressure
A cylinderical rod subjected to a tensile strain within the elastic limit undergoes a volume change. If the volume strain is equal to half the tensile strain, then the Poisson’s ratio of the rod is
0
0.33
0.44
0.25
0.44
The surface tension of a liquid, at critical temperature is
indeterminate.
zero.
infinity.
same as that at any other temperature.
zero.
Large scale fire on fuel gas line is normally extinguished by
water
steam
foam
nitrogen
nitrogen
Brazing is the joining of metals
without melting the base metal.
with a non-ferrous filler.
both (a) & (b).
neither (a) nor (b).
both (a) & (b).
Moist climate is the most favourable factor in the site selection far a
steel plant
textile factory
petroleum refinery
coke oven battery
textile factory
Dry saturated steam can be converted into superheated steam by
increasing its cross-sectional area of flow.
passing it through a pressure reducing valve.
forcing it downwards through a vertical tube.
none of these
passing it through a pressure reducing valve.
Pick out the wrong statement.
A. Copper is the metal having the highest electronic conductivity.
B. Hardenability & weldability of metals are inversely related.
C. Covalant bonding formed by sharing of electrons is present in all semi-conductor materials.
D. Glass transition temperature applies to ‘polymers’ but not to ‘glasses’.
Copper is the metal having the highest electronic conductivity.
Increasing sulphur content in pig iron tends to make it
soft
hard
tough
ductile & malleable
hard
Oxyacetylene reducing flame is used while carrying out welding on
alloy steel
grey cast iron
mild steel
high carbon steel
mild steel
M10 index of coke indicates its
compressive strength.
hardness.
abrasion resistance.
impact strength.
abrasion resistance
Gantt charts are used for streamlining the
inventory control
production schedule
sales forecasting
quality control
production schedule
In the Bayer’s process, bauxite is digested under pressure using
H2SO4
NaOH
NH
HCl3
NaOH
Circular cross section machine parts which are symmetrical about the axis of rotation are made by hot
piercing
spinning
drawing
extrusion
spinning
The substance used as a smoke screen in warfare is
C2H2
SiCl4
P2O5
PCl5
SiCl4
The same volume of all gases is representative of their
specific gravities.
densities.
gas characteristic constants.
molecular weights.
molecular weights.
Fluorine is not a constituent of
freon
chloroform
teflon
fluorocarbons
chloroform
The most commonly used combustion system manufactured in India for the thermal power plant boilers is the __________ combustion system.
pulverised fuel
travelling grate stoker firing
circulating fluidised bed
fluidised bed
pulverised fuel
During solid state sintering of powders, the following mechanism can be active.
Evaporation and condensation.
Solid state diffusion processes.
Liquid formation in grain boundaries.
Creation of more dislocations.
Solid state diffusion processes.
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
1127
Regeneration of molecular seive requires it to be heated to a temperature of about __________ °C.
80-120
200-300
600-800
1000-1100
1000-1100
The ultimate strength in tension for steel is __________ times the ultimate strength in shear.
0.5
0.9
1.5
2.5
1.5
The activity of pure hydrogen gas at 1000°C and 5 atm pressure
is always less than 1.
is always greater than 1.
can be 5.
depends on the choice of the standard state.
depends on the choice of the standard state.
Which of the following transducers is most commonly used for the measurement of shock and vibration ?
Linear variable differential transducer (LVDT)
Dial gauge
Accelerometer
none of these
Accelerometer
The power of a low capacity prime mover is most suitably measured by a __________ type dynamometer.
driving
transmission
absorption
none of these
absorption
__________ addition increases the depth of hardness of steel.
Chromium
Nickel
Tungsten
Vanadium
Chromium
The most important consideration in value engineering is the
profit maximisation.
customer satisfaction.
cost reduction.
process improvement.
customer satisfaction.
Lime contains about 90% CaO. Percentage CaO present in limestone is about
25
50
70
80
50
The most important material handling system in an integrated steel plant is the
belt conveyor
diesel locomotive
truck
overhead hoists & cranes
diesel locomotive
Property of a material to resist a tensile force without giving away is a measure of its
stiffness
toughness
resilience
tenacity
tenacity
Cast iron has the unique property of high
ductility
damping characteristics
hardness
malleability
damping characteristics
Steels with high carbon equivalent have poor weldability, because in these steels during welding
A. carbon and other alloying elements get oxidised from the weld pool.
B. excessive ferrite forms in the heat affected zone leading to poor toughness of the weld.
C. martensite forms in the heat affected zone leading to poor toughness/ductility of the weld.
D. segregation of carbon and other element occurs in the weld pool leading to poor properties of the weld.
martensite forms in the heat affected zone leading to poor toughness/ductility of the weld.
If the pH value of a solution of sodium chloride is 7; then what will be the pH value of the solution after its electrolysis ?
7
< 7
> 7
0
> 7
Measurement of the area of the indented surface is not involved in the __________ hardhes testing method.
Vicker’s
Rockwell
Knoop
Brinell
Rockwell
Salvage value is the most flexible criteria for analysing a financial investment. ‘Salvaging’ means
A. disposing off a machine/property on as is where is basis.
B. disposing off machine/property, which is no longer useful in the present scenerio.
C. mortgaging the obsolete machine/property.
D. writing off the obsolete machine/ property.
disposing off machine/property, which is no longer useful in the present scenerio.
Super conduction in metals is observed at a temperature of __________ °K.
<100
>100
about 273
about 373
> 100
Springback in sheet metal bending depends on the
elastic limit
bend radius
degree of bend
thickness of sheet
thickness of sheet
The yield point in fatigue loading compared to that in static loading is less. The ratio of ultimate tensile strength to endurance limit of a material subjected to fatigue loading is
0.5
1
1.5
2
2
Which of the following is not used as a fuel in rocket propellaht ?
Liquid hydrogen
Liquid oxygen
Liquid hydrazine
Kerosene oil
Liquid oxygen
Hypo (sodium thiosulphate) because of its complex forming behaviour is used in photography to remove undecomposed silver bromide as a soluble complex for __________ of the picture.
printing
developing
colour
fixation
developing
Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature.
copper
steel
aluminium
brass
copper
__________ welding will be the most suitable for butt welding two 20 cms thick boiler drum mild steel plates.
Electrical resistance
Electroslag
Plasma torch
Submerged arc
Electroslag
Machinability of hard alloys & tool steels is improved by
spherodising
annealing
tempering
normalising
annealing
LASER
stands for Light Amplification by Stimulated Emission of Radiation.
has the same intensity as visible light.
can’t be used for cutting metals.
none of these.
stands for Light Amplification by Stimulated Emission of Radiation.
__________ forces do not act in case of fluids.
Vibratory
Centrifugal
Elastic
Tensile
Tensile
Which of the following is not a natural abrasive ?
Silicon carbide
Quartz
Corundum
Emery
Silicon carbide
The function of a nozzle provided in steam turbine is to
throttle down (i.e., reduce) the pressure of steam.
convert internal energy into kinetic energy.
increase the velocity of steam.
all (a), (b) & (c).
all (a), (b) & (c).
Which of the following polymers is obtained by copolymerisation of three monomers ?
SAN
ABS
SBR
PTFE
ABS
Silicon percentage in the silicon steel used for electrical appliances/equipments is
0.3-0.4
12-14
3-4
20-25
3-4
Material of construction of foundary crucible is
graphite
lead
porcelain
stainless steel
graphite
Titanium can be easily welded using __________ welding.
submerged arc
TIG
shielded metal arc
electroslag
TIG
Feed check valve is used in steam boilers to
A. check the water level in the boiler.
B. check the feed water flow rate.
C. feed high pressure water to boiler and guard against its backflow through it.
D. none of these.
feed high pressure water to boiler and guard against its backflow through it.
Three elastic constants for a completely anisotropic elastic material which follows the Hooke’s law are young’s modulus, elastic limit stress and yield stress. Which of the following properties is most sensitive to increase in strain rate ?
Tensile strength.
Elastic limit.
Proportional limit.
Yield strength.
Proportional limit.
Swaging is a/an __________ operation.
piercing
forging
extrusion
drawing
forging
Pig iron is
made from cast iron.
made from wrought iron.
the one, which comes out of the blast furnace.
free from impurities.
the one, which comes out of the blast furnace.
Classification of metal forming processes into hot and cold working is based on the following parameters.
Stacking fault energy.
Recrystallisation temperature.
Solidus temperature.
Transformation temperature.
Recrystallisation temperature.
Kinematic viscosity of water as compared to that of air is
more
same
15% more
15% less
15% less
Which of the following is the most suitable for removing fine particles (< 1 micron diameter) from air below its dew point ?
Venturi scrubber
Electrostatic precipitator
Cyclone separator
Fabric filter
Electrostatic precipitator
Which of the following is the terminology used for the temperature at which the phase changes occur in a metal ?
Critical temperature.
Recrystallisation temperature.
Phase transformation temperature.
Transition temperature.
Critical temperature.
Puddling process is used for converting pig iron into
cast iron
wrought iron
mild steel
semi-steel
mild steel
Addition of __________ in steel can help in increasing the depth of hardness.
nickel
chromium
vanadium
tungsten
vanadium
On-off control
A. fully opens the final control element, when the measured variable is below the set point.
B. fully closes the final control element, when the measured variable is above the set point.
C. is a two position control (fully open or fully closed) control adequate to control a process with slow reaction and minimum dead time or transfer lag.
D. none of these.
is a two position control (fully open or fully closed) control adequate to control a process with slow reaction and minimum dead time or transfer lag.
The tensile load-elongation curve of a metal does not describe
work hardening
yield stress
anisotropy index
necking strain
anisotropy index
Usual value of the resistance suitable for a wire resistance strain gauge is __________ ohms.
20
80
120
500
120
Permanent set in a material is produced by subjecting it to
triaxial loading.
fatigue loading.
stresses beyond the elastic limit.
tensile & compressive loads simultaneously.
stresses beyond the elastic limit.
The following is a typical anionic collector used in flotation.
Ethyl dixanthogen.
Trimethyl cetyl ammonium bromide.
Potassium ethyl xanthate.
lAuryl amine hydrochloride.
Potassium ethyl xanthate.
A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution.
neutral
ideal
buffer
zero pH
buffer
Pick out the wrong statement.
Weldability of high carbon steel is poorer compared to low carbon steel.
Invar is a magnetic alloy.
Magnetic permeability of the diamagenetic material is less than one.
Martensitic transformation never goes to complection ( i.e., 100%) at room temperature.
Invar is a magnetic alloy.
The bolt is subjected to __________ when the nut is tightened by putting the washer beneath it.
tension
shear
compression
bending & tension
tension
Which of the following is not categorised as the ore agglomeration process ?
Nodulising
Pelletising
Balling
Briquetting
Balling
With increase in temperature, the surface tension of water
increases
decreases
remains constant
increases linearly
decreases
A reduction in thermal resistance during heat transfer does not occur in the
A. convection heat transfer by stirring the fluid and cleaning the heating surface.
B. conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity.
C. radiation heat transfer by increasing the temperature and reducing the emis-sivity.
D. none of these.
radiation heat transfer by increasing the temperature and reducing the emis-sivity.
Unit of viscosity in CGS system is
gm .cm-1 sec-1
gm . cm2 . sec-2
gm .cm-2, sec-1
gm . cm . sec-1
gm .cm-1 sec-1
Shaft/rotor speed is most accurately measured by a
frequency counter.
tachometer.
strobometer.
speedometer.
strobometer.
__________ test determines the yield strength, Young’s modulus of elasticity, percentage reduction in area & percentage elongation of a material.
Tensile
Fatigue
Impact
None of these
Tensile
The rolling process can not be used to produce
plates
rods
tubes
wires
tubes
Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is
3
5
0.5
1.5
5
Presence of nickel & chromium in steel does not raise its
elastic limit
machining properties
ductility
resilience
elastic limit
Hot extrusion process is not used for making
cast iron pipe for domestic water supply.
aluminium curtain rods.
stainless steel tubes used in furnitures.
any of these.
cast iron pipe for domestic water supply.
Addition of __________ to steel does not help in improving its machinability.
sulphur
silicon
lead
phosphorous
silicon
Quartz is a __________ material.
diamagnetic
ferromagnetic
ferroelectric
piezoelectric
piezoelectric
The units of the rate constant for a second order reaction are
sec-1. mole°.
moles1. sec-1.
moles-1. sec1.
moles1. sec1.
moles-1. sec1.
The most serious manufacturing defect from fracture toughness point of view is
surface roughness
pores
spherical inclusion
crack
crack
Leakage in a cooking gas cylinder is detected by
radio-isotopes.
pouring soap solution on the surface and locating the gas bubbles.
halide torch.
pungent smell of mercaptans present in the gas.
pungent smell of mercaptans present in the gas.
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
Tungsten carbide
The ratio of mass of a neutron to that of an electron is about 1839. What is the ratio of the mass of a proton to that of an electron?
159
1837
2537
10000
1837
Laser is a device to produce
gamma rays.
microwaves.
a beam of white light.
a beam of coherent light.
a beam of coherent light.
Addition of small amount of __________ to grey cast iron is done to produce nodular grey cast iron.
manganese
phosphorous
magnesium
chromium
magnesium
Minimum thermal efficiency of a steam boiler may be around __________ percent
25
45
65
20
20
The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the ‘Curie point’, which is __________ °C.
768
908
1400
1539
768
Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails
below the yield point.
above the yield point.
below the elastic limit.
at the elastic limit.
below the yield point.
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
Lead
Particle nature of cathode rays is proved due to the fact that they
travel in a straight line.
get deflected by magnetic electric field.
produce fluorescence.
heat the exposed material.
get deflected by magnetic electric field.
The most commonly used moderator in nuclear power plants is
graphite
light water
heavy water
berellium
graphite
Babbit lining is used on brass/bronze bearings to increase the
antifriction properties.
compressive strength.
bearing resistance.
wear resistance.
wear resistance.
The heat of neutralisation remains constant, when there is a reaction between dilute solutions of strong
base and strong acid.
base and weak acid.
acid and weak base.
none of these.
base and strong acid.
Joining of thin foils is preferred to be done by
gamma rays
X-rays
microwaves
gas welding
microwaves
Which of the following metals reacts violently with water ?
Mercury
Sodium
Calcium
Magnesium
Sodium
A steam carraying 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.
remain unaffected.
Damage to metal surface by mechanical action is called
pitting
corrosion
erosion
none of these
erosion
The escape velocity of a body on earth which is independent of its mass is about __________ km/second.
3
7
11
15
11
Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils ?
Elaiden test
Reichart-Meissl value test
Henter value test
Iodine value test
Elaiden test
The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity.
0
100
50
none of these
100
The process of removal of scale formed during hot rolling of steel is termed as
descaling
shot blasting
pickling
skimming
pickling
A psychrometer does not measure the __________ temperature of moist air.
dew point
dry bulb
wet bulb
none of these
dew point
An ideal material for making cooking vessels should have
high heat capacity.
low heat capacity.
high thermal conductivity.
both (b) and (c).
both (b) and (c).
Which of the following approaches the ideal gas behaviour most closely ?
Wet steam
Saturated steam
Superheated steam
Saturated water
Superheated steam
Which of the following is not the function of a volute casing provided in a centrifugal pump ?
To reduce the head loss in discharge.
To increase the pump efficiency.
To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at constant velocity.
To increase the pump discharge rate.
To increase the pump discharge rate.
The pressure outside a bubble/droplet of liquid is __________ the internal pressure.
greater than
less than
equal to
unpredictable ; depends on the bubble size
less than
Two wires of the same radius & material having length in the ratio of 1 : 2 are stretched by the same force. The strain produced in the two wires will be in the ratio of
1:1
1:2
2:1
1:4
1:1
Powder metallurgy technique is used in the production of __________ tools.
tungsten carbide
high carbon steel
high speed steel
drilling
tungsten carbide
Principal alloying elements of cast tool alloys which have very high wear resistance & high temperature strength are
cobalt, chromium & tungsten,
cobalt, chromium & nickel.
molybdenun, tungsten & chromium.
cobalt, zirconium & molybdenum.
cobalt, chromium & tungsten,
Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)?
Aluminium
Copper
Titanium
Stainless steel
Titanium
Which of the following is an ore dressing operation ?
Classification
Smelting
Roasting
None of these
Classification
Gratings is associated with the measurement of
linear displacement.
concavity/convexity.
surface texture.
flatness.
linear displacement.
__________ joint is mostly used for joining pipes carrying water at low pressure.
Nipple
Socket
Union
Bell and spigot
Socket
Adhesives
can’t be used in the form of pressure sensitive tapes.
can’t join two dissimilar metals.
cure instantaneously after application on a surface.
none of these.
none of these.
In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C.
20
60
120
∞
∞
Normalising of a casting does not
induce stresses in it.
refine its grain structure.
reduce seggregation.
improve its mechanical properties.
induce stresses in it.
The swift cup test evaluates the following property of a sheet metal.
Stretchability
Drawability
Bendability
None of these
Drawability
__________ is the most important element, which controls the physical properties of steel.
Manganese
Silicon
Carbon
Vanadium
Carbon
The emf of a Deniell cell Zn|Zn2+||Cu2+|Cu can be increased by
decreasing the surface area of the electrodes.
increasing the concentration of zinc sulphate solution.
increasing the surface area of the electrodes.
increasing the concentration of copper sulphate solution.
increasing the concentration of copper sulphate solution.
A hot short metal is
hard when hot.
brittle when cold.
brittle when hot.
brittle under all conditions.
brittle when hot.
Corrosion rate can not be lowered by reducing the __________ of the corroding medium.
concentration
velocity
temperature
none of these
concentration
Routing in production, planning & control is concerned with the
sequence of operation to be performed.
progress of work performed.
authorisation of work to be performed.
balancing of load on machines.
sequence of operation to be performed.
A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm2.
6
18
38
52
18
The total frictional resistance to fluid flow does not depend upon the
roughness of the surface.
fluid pressure.
fluid density.
fluid velocity.
fluid pressure.
Stretcher strains found in a low carbon sheet are associated with the
texture.
dislocation density.
yield point phenomenon.
thickness of the sheet.
yield point phenomenon.
The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system
is as light as possible.
has very high C.O.P.
employs minimum quantity of refrigerant.
consumer minimum horse power.
is as light as possible.
Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
A. lower cost.
B. abundant availability.
C. resistance to vegetable acids as the tin plate are commercially used in ‘canning’ industry.
D. none of these.
resistance to vegetable acids as the tin plate are commercially used in ‘canning’ industry.
Which of the following is resistant to the action of both heat & chemicals ?
Boro silicate glass,
Silica glass.
Soda lime glass.
none of these.
Boro silicate glass,
Metallic surveying tapes are made of __________ which has a low co-efficient of expansion & enough strength.
invar
hastealloy
duralumin
monel metal
invar
Which of the following is a unit of time ?
Barn
Light year
Angstrom
none of these
none of these
__________ furnace is generally used in the non-ferrous foundaries.
Direct arc
Indirect arc
Resistance
Induction
Indirect arc
Steel & cast iron pipes are produced by __________ casting.
slush
die
investment
true centrifugal
true centrifugal
The taper provided on pattern for its easy & clean withdrawal from the mould is termed as the __________ allowance.
casting
pattern
draft
distoration
draft
Gas turbine normally employs a constant __________ cycle.
pressure
temperature
volume
none of these
pressure
Which of the following relationships is correct for relating the three elastic constants of an isotropic elastic material (where, E = Young’s modulus, G = Modulus of rigidity or shear modulus v = Poisson’s ratio) ?
E = 2G (1 + v)
E = G (1 + v)
E = G (1 + v)/2
E = 2G (1 + 2v)
E = 2G (1 + v)
Electrostatic separation of minerals from each other is based on their differences in the following property.
Densities.
Magnetic permeabilities.
Electrical conductivities.
Hardness.
Electrical conductivities.
Natural water contains approximately __________ percent of heavy water.
0.015
0.71
1.2
3.5
0.015
The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air.
ambient
dry bulb
dew point
wet bulb
dew point
The order of a chemical reaction
can be determined only experimentally
can be determined from the stoichiometry of the reaction.
can not be zero.
can be fractional.
can be determined from the stoichiometry of the reaction.
Pick out the wrong statement.
A. Lead can creep under its own weight at room temperature.
B. The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement.
C. Recrystallisation temperature decreases with decrease in strain in a cold worked metal.
D. With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase.
Recrystallisation temperature decreases with decrease in strain in a cold worked metal.
Pick out the wrong statement.
Reflectivity of gases is very low.
Absorptivity for metals is very high.
Reflectivity for non-conducting materials is low.
Reflectivity of polished surfaces is very high.
Absorptivity for metals is very high.
For efficient performance of a blast furnace, the extent of reduction of Wustite (FeO) should be
100% indirect reduction.
100% direct reduction.
50-60% indirect reduction.
30-40% indirect reduction.
50-60% indirect reduction.
Identify the false statement
A. Martensitic steels are less susceptible to pitting corrosion than austenitic steels.
B. Pitting corrosion is usually very localised.
C. Hydrogen embrittlement is facilitated by tensile stress.
D. Stress corrosion cracking is facilitated by tensile stress.
Martensitic steels are less susceptible to pitting corrosion than austenitic steels.
__________ can replace tungsten in high speed steel.
Chromium
Vanadium
Cobalt
Molybdenum
Cobalt
Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity.
300
800
1400
2000
1400
Fatigue strength of a material can not be increased by
cold working
hot working
shot peening
any of these
hot working
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.
thermal co-efficient of expansion.
Out of the following the refractive index is the highest for
glass
diamond
brine
kerosene
diamond
Function of blow down valve in a boiler is to
maintain the drum level.
keep the drum pressure constant.
drain out the sludge from the drum.
empty the boiler during shutdown.
drain out the sludge from the drum.
Insulation of liquid surface can be achieved by __________ on top of its surface.
floating hollow polypropylene spheres
spraying alumina powder
putting cement
none of these
floating hollow polypropylene spheres
Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50 wt% B is
R ln 2
-R ln 2
3 R ln 2
-3R ln 2
R ln 2
Out of the following, the lowest packing of atoms exists in __________ crystal lattice structure.
hexagonal close, packed (hcp)
face centred cubic (fcc)
body centred cubic (bcc)
simple cubic
simple cubic
Cadmium in zinc leach liquor is removed by cementation using
zinc
iron
nickel
copper
zinc
In electrical resistance welding, distortion results from the use of improper
clamping methods
electrodes
current
filler material
clamping methods
The conventional mechnical transducer, which converts pressure signal to displacement signal is
spring
manometer
strain gauge
none of these
manometer
Pick out the wrong statement.
A. Seam welding, projection welding & spot welding are the classification of electrical resistance welding.
B. Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded)
c. In spot welding, two pieces to be joined are overlapped and placed between two electrodes.
D. Mild steel sheet can not be spot welded.
Mild steel sheet can not be spot welded.
Austempering of steel requires.it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to
sorbite
bainite
martensite
troostite
bainite
A compact estimate about the amount of materials handling between various work stations is obtained from the
gantt chart
bin chart
string diagram
travel chart
travel chart
Lead is poured into the joint between two- __________ pipes.
mild steel
concrete
cast iron
asbestos cement
cast iron
The concentration of (H+) ions is 4 x 10-5 in a solution. Then pH of the solution will be (Given log 4 = 0.6 )
4.4
5.6
8.4
2.4
4.4
Age hardening is connected with
babbit metal
gun metal
stainless steel
duralumin
duralumin
With decrease in the grain size of a material, its creep resistance
increases.
decreases.
remains constant.
either (a) or (b) ; depends on the material.
remains constant.
__________ rubber is generally used for making ‘O’ rings used for vacuum sealings.
Natural
Neoprene
Butadiene
Nitrile
Neoprene
Gross national product (GNP) means the total value of __________ in a country.
goods produced
gold reserve
earning of the citizens
taxes paid
goods produced
Energy to be supplied to the radioactive nucleus for the emission of a neutron is __________ MeV.
0.8
7.8
200
10000
0.8
The co-ordination number in simple cubic structure is
4
6
8
12
6
Out of the following surfaces, the emis-sivity will be minimum for
aluminium foil
concrete
plaster
smooth glass
concrete
The property of material, by which a given amount of energy is absorbed by it without plastic deformation, is called the
resilience
toughness
ductility
impact strength
resilience
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
less than
__________ the exhaust gas is an indication of the incomplete combustion of fuel.
Low temperature of
High temperature of
High % of CO in
High % of CO2 in
High % of CO in
Air/fuel ratio on molar (volume) basis for combustion of methane with theoretical quantity of air with be
9.5:1
12.5:1
15.5 :1
18.5 : 1
9.5:1
Frost formation on the evaporator tubes in the domestic refrigerators
can be prevented by proper design.
decreased compressor power.
causes heat loss due to poor heat transfer.
is immaterial.
causes heat loss due to poor heat transfer.
Function of feed check valve in a boiler is to
facilitate circulation of high pressure feed water.
check the water level in the boiler drum.
prevent the back flow of water.
regulate the water flow to boiler.
prevent the back flow of water.
Ganister contains maximum percentage of
FeO
SiO2
MgO
MnO2
SiO2
Nitrogen is not an essential component of
protein
urea
oils & fats
any of these
oils & fats
In inventory control theory, the economic order quantity (EOQ) is the
lot size corresponding to break even analysis.
average level of inventory.
optimum lot size.
none of these.
optimum lot size.
The main charge in blast furnace is usually
iron ore & coke.
iron ore, coke & air.
limestone, coke & iron ore.
limestone, sand & iron ore.
limestone, coke & iron ore.
The atmospheric temperature during melting of ice/snow (in the atmosphere)
decreases
increases
remains same
may increase or decrease ; depends on the altitude where snow melts
decreases
At room temperature, F.C.C. crystal structure is observed in
lead
cupro-nickel
titanium
tungsten
lead
The basic function of the drum in a boiler is to
act as a storage for feed water.
act as a storage for steam.
separate steam from water.
remove settling impurities from steam.
separate steam from water.
Pick out the wrong statement.
A. The X-rays can not be deflected by electric field unlike cathode rays.
B. The intensity of X-rays can be measured by ionisation current produced due to the ionisation of gas by X-rays.
C. The quality of X-rays can be controlled by varying the anode-cathode voltage.
D. Crystal structure of a material can be studied by an electron microscope.
C. The quality of X-rays can be controlled by varying the anode-cathode voltage.
Colloids can be purified by
dialysis
reverse osmosis
coagulation
peptization
dialysis
The most prominent single cause of corrosion in boilertubes, drums, economisers and steam superheaters in a thermal power plant boiler is the
water alkalinity & leakage.
hydrazine addition during feed water treatment.
release of non-condensable gas from water in the boiler.
scale formation.
release of non-condensable gas from water in the boiler.
Maximum carbon content in cast iron is __________ percent.
3.8
4
4.3
4.6
4.3
Screws are specified by their __________ diameters.
minor
major
pitch
none of these
major
The stress at which extension of the material takes place more rapidly as compared to the increase in load is termed as the __________ point of the material.
elastic
ultimate
yielding
breaking
yielding
A material being tested for endurance strength is subjected to the __________ load.
impact
completely reversed
dynamic
static & dynamic
completely reversed
With increase in pressure, the latent heat of steam
increases.
decreases.
remains unchanged.
data insufficient; can’t be predicted.
decreases.
‘Flare tower’ used in industry is meant for
venting off (after burning) the excess inflammable/toxic gases at high pressure.
absorbing the pollutant gases from the furnace exhaust.
cooling of furnace exhaust gases.
none of these.
venting off (after burning) the excess inflammable/toxic gases at high pressure.
Which of the following has the highest modulus of elasticity (about 7 x 106 kg/cm2) ?
High speed steel
Stainless steel
Tungsten carbide
Superalloys
Tungsten carbide
Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to
achieve very high purity of aluminium (99.9%).
keep the electrolyte in liquid condition by the generation of heat.
electrolytically dissociate alumina.
both(b) & (c).
both(b) & (c).
All radiations falling on a black body are
refracted
reflected
transmitted
absorbed
absorbed
Styrofoam is the commercial name of
polyurathene
polystyrene
polyacrylonitrile
polybutadiene
polystyrene
Dryness fraction of dry steam is
0
∞
1
0.5
1
Ceramic materials are
organic in nature.
stronger in compression than in tension.
always amorphous in nature.
always bad heat conductors.
stronger in compression than in tension.
Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part?
Anodising
Tempering
Carburising
Annealing
Tempering
Heat required to raise the temperature of a body by 1 °C is called its
heat capacity.
specific heat capacity.
thermal conductivity.
water equivalent.
heat capacity.
Coating of zinc over steel is known as
cladding
galvanising
anodising
passivation
galvanising
Air-petrol ratio in an automotive petrol engine is around
14 : 1
22 : 1
25 : 1
4 : 1
14 : 1
The property of material, by which a given amount of energy is absorbed by it, without plastic deformation is called
resilience
toughness
ductility
impact strength
resilience
Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode
A. occurs higher in the electro-chemical series of metals.
B. is exemplified by magnesium plate.
C. is much cheaper than the cathodic base material to be guarded against corrosion.
D. all (a), (b) & (c).
D. all (a), (b) & (c).
Electrochemical corrosion can occur, only if __________ is present in contact with metal.
air
oxygen
liquid medium
gaseous medium
liquid medium
Crystallisation of polymers is an undesirable property. Crystallisation of celluloid is prevented by adding
glycerol
nitro cellulose
camphor
none of these
none of these
Preheating prior to welding is done for the purpose of
decreasing cooling rate.
facilitating fusion of high melting metals.
preventing hot cracking.
ensuring full penetration.
decreasing cooling rate.
Presence of sulphur in steel reduces the
hardness.
grain size.
tensile strength.
toughness & transverse ductility.
toughness & transverse ductility.
Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother?
Cresylic acid
Xanthaies
Pine oil
all ‘a’ ‘b’ & ‘c’
Xanthaies
Otto cycle used in spark ignition petrol engines is also known as the constant __________ cycle.
volume
pressure
heat
none of these
volume
Fire on fuel oil lines can be extinguished by
foam
steam
water
carbon dioxide
foam
In a furnace with heating element temperature at 1700°C, the dominant machanism of heat transfer will be
conduction
radiation
natural convection
forced convection
radiation
Optical activity is a/an __________ property.
additive
constitutive
both (a) & (b)
neither (a) nor (b)
both (a) & (b)
Solution loss reaction occurs
in the blast furnace shaft.
during pretreatment of hot metal.
in the L.D. process.
during deoxidation in the ladle.
in the blast furnace shaft.
Out of the following materials, the one which generally exhibits an yield point is
hard bronze
soft brass
cold rolled mild steel
hot rolled mild steel
hot rolled mild steel
The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 - T2)/T1. The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2 is given by
T1/(T1-T2)
T2/(T1-T2)
T1/T2
T2/T1
T2/(T1-T2)
Diamagnetic materials
are magnetised by eddy currents only.
are non-magnetic and can not be magnetised.
are magnetised in direction opposite to the magnetic field.
can be magnetised in one direction only.
are magnetised in direction opposite to the magnetic field.
In connection with corrosion of metals, passivation is the process that
intensifies deterioration.
changes the composition of the metal.
inhibits further deterioration.
none of these.
inhibits further deterioration.
With increase in impurities in metals, their corrosion resistances
increase
decrease
remain same
may increase or decrease ; depending on the type of metal
decrease
Most important property of steels for use in automobile bodies is the
formability
yield strength
toughness
resilience
formability
Consideration of the creep is the most important in case of the
blades of gas turbine.
piston of an I. C. engine.
flywheel of steam engine.
cycle chain.
blades of gas turbine.
Non-ferrous alloys used for making cutting tools need not have high
abrasion resistance
toughness
red hardness
cutting speed
toughness
Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by __________ have residual stresses.
forging
cold rolling
hot rolling
casting
cold rolling
Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be
more
less
same
either more or less; depends on the climatic conditions.
less
Glycerene is used as a coolant in cooling of some engines instead of water, because
its higher boiling point (290°C) increases its heat carrying capacity.
compartively less weight of coolant is required.
smaller radiator can be used.
all a, b & c.
all a, b & c.
Cold working of a material results in increase in hardness, which is termed as the __________ hardening.
cold
work
age
induction
work
Potable water means the water used for
fire-fighting
cooling
drinking
evaporation to produce steam
drinking
One ton of refrigeration is not equivalent to the heat removal rate of
200 BTU/minute
50 kcal/minute
50 kJ/sec.
3.5 KW
50 kJ/sec
Starting friction is low in case of the __________ lubrication.
boundary
hydrodynamic
hydrostatic
mixed/semi-fluid
hydrostatic
Ultimate strength in tension as compared to that in shear for steel is
half
one third
one and half times
one fourth
one and half times
Which of the following heat treatment processes is usually applied to castings ?
Tempering
Annealing
Normalising
Carburising
Carburising
Photographic plates are coated with
silver nitrate
silver halide
calcium silicate
metallic silver
silver halide
Hardening of steel is not possible, unless it is heated __________ critical point.
above the highest
above the lowest
between the first & second
between the second & third
above the lowest
Isotropic materials have the same __________ in all directions.
induced stresses
density
elastic properties
thermal properties
elastic properties
The most important requirement for aluminium industry is the availability of cheap
ore
electrical power
labour
& abundant water
electrical power
Spheriodising of a material is a/an __________ process.
normalising
annealing
tempering
hardening
annealing
The trace metal present in insulin is
Cu
Zn
Fe
Ni
Zn
Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
retained austenite.
martensite formation.
relatively high sulphur content in the base metal.
sufficient hydrogen present in the welding arc.
martensite formation.
Drossing is a __________ operation.
smelting
dressing
roasting
dressing
roasting
Most of the phosphorous present in the blast furnace burden enters into
hot metal
flue gases
slag
refractory lining
hot metal
During sensible heating of humid air
relative humidity increases.
dew point remains constant.
dry bulb & wet bulb temperature increases.
both ‘b’ & ‘c’.
both ‘b’ & ‘c’.
Iron content in Indian iron ore is about __________ percent.
80-85
60-65
40-45
20-25
60-65
The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is
full annealing
bright annealing
patenting
none of these
patenting
__________ of hard alloy and tool steel is done to make it easily machinable.
Case carburising
Tempering
Normalising
Annealing
Tempering
Which of the following mainly decides the current to be employed is arc welding ?
Electrode size
Plate thickness
Voltage across the arc
Welded portion length
Electrode size
Temperature attained in soldering of metals is about __________ °C.
150-300
400-500
650-800
1000-1100
150-300
The normal stress is the same in all directions at a point in a fluid, only when the fluid
is at rest & has zero viscosity.
is frictionless.
fluid layer has no motion relative to an adjacent layer of fluid.
is incompressible & frictionless.
is incompressible & frictionless.
A 2 kg object weighs 1.8 kgf on a spring balance. The value of ‘g’ at that location in m/sec2 is
8.82
9.81
10.88
0.95
8.82
In chemical dehumidification of air
both specific humidity & dry bulb temperature increases.
both specific humidity & dry bulb temperature decreases.
specific humidity decreases & dry bulb temperature increases.
specific humidity increases & dry bulb temperature decreases.
specific humidity decreases & dry bulb temperature increases.
What is the pH of distilled water ?
0
1
7
14
7
Pick out the correct statement.
A. Hot worked materials are subjected to annealing to remove internal stresses.
B. Annealing of steel hardens it slightly
C. Normalising of a material induces stresses.
D. Tempering of a material improves ductility & toughness but reducess hardness & brittlenes.
Tempering of a material improves ductility & toughness but reducess hardness & brittlenes.
Dielectric
is an electrical insulating material.
of low resistivity is preferred.
should have high thermal conductivity.
need not defy the corrosive action of chemicals.
is an electrical insulating material.
Normalising of an object does not
refine coarse grain structure obtained during hot working.
improve ductility.
improve yield strength.
improve machanical properties.
improve ductility.
Plasma is
a high temperature neutral gas.
nothing but ionised gas.
a source of steady and highest controllable pressure.
formed at very low temperature.
nothing but ionised gas.
The machanism involved in the removal of metal in drilling operation is by
compression
extrusion
shearing
both ‘b’ & ‘c’
both ‘b’ & ‘c’
Thermal conductivity of a material does not depend upon its
mass
volume
surface area
all ‘a’, ‘b’ & ‘c’
all ‘a’, ‘b’ & ‘c’
Carbon supply in pack carburising process is in the form of
charcoal
calcium carbide
hydrocarbon oil
graphite
charcoal
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.
partial condensation of steam.
Powder metallurgy is used to produce
high precision components with complex cavities and sharp features.
components of large size.
porosity free components.
components of such alloys whose constituents do not form alloys readily.
porosity free components.
Catalyst used in the catalytic converter employed in automobiles to convert CO into CO and for complete oxidation of un-burnt hydrocarbons is
nickel
cobalt
vanadium
platinum
platinum
For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot ?
Temperature - entropy.
Temperature - pressure.
Enthalpy - entropy.
Enthalpy-pressure.
Temperature - entropy.
The main constituent of bones is
CaF2
Ca3(PO4)2
CaCO3
CaCl2
Ca3(PO4)2
Globular form of cementite is formed during the __________ process.
spherodising
hardening
annealing
normalising
hardening
Faraday’s law of electrolysis is related to the
cation speed.
atomic number of the cation.
equivalent mass of the electrolyte.
none of these.
equivalent mass of the electrolyte.
The two elements required to form substitutional solid solution should not have
same crystalline structure.
same valancy
widely differing electronegativity.
same atomic sizes.
widely differing electronegativity.
Rankine cycle comprises of two isothermal and two __________ processes.
isobaric
polytropic
isentropic
none of these
none of these
Coating provided on the electrodes used in the arc welding is not expected to
add alloying elements.
prevent electrode from contamination.
stabilise the arc.
provide protective atmosphere to weld.
prevent electrode from contamination.
Desalination of water
makes it potable.
makes it non-potable.
means distillation of water.
none of these.
makes it potable.
Viscoelastic behaviour is observed in __________ materials.
non-crystalline organic polymeric
ceramic
all crystalline
all amorphous
non-crystalline organic polymeric
Probability of cavitation occuring becomes very high, when the local __________ resulting in water bubbles formation, which on rupture cause cavitation
pressure falls below the vapour pressure
pressure becomes very high
temperature becomes low
all ‘a’, ‘b’ & ‘c’
all ‘a’, ‘b’ & ‘c’
Which of the following materials has the poorest electrical conductivity ?
Carbon
Aluminium
Silver
Stainless steel
Carbon
Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is
black
silver grey
green
yellow
silver grey
What is the percentage of chromium in 18-4-1 high speed steel ?
1
4
18
23
18
Preheating before welding is done to
make the plate softer.
burn oil & grease sticking to plate surfaces.
avoid plate distortion.
prevent cold cracks.
prevent cold cracks.
Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity)
1/k
k
k2
1/k2
k
Dew point temperature always gives an indication of the __________ of the moist air.
dryness
moisture content
coolness
latent heat
moisture content
For a first order chemical reaction, the concentration of the reactant decreases __________ with time.
linearly
exponentially
logarithmically
inversely
linearly
Air standard Otto cycle is more efficient than the diesel cycle for the same
heat addition & compression ratio.
heat addition & pressure.
compression ratio & pressure.
cylinder dimension & rpm.
heat addition & compression ratio.
In case of brasses, with decreasing zinc percentage and increasing copper percentage, its __________ increases.
percentage elongation
brinell hardness
tensile strength
all ‘a’ , ‘b’ & ‘c’
percentage elongation
A suitable lubricant used for watches is
metallic soap solution
grease
palm oil
hazel-nut oil
hazel-nut oil
Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
white
cast
wrought
pig
wrought
For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = - 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be
30000 J
60000 J
90000 J
240000 J
90000 J
Projection welding & stud welding is categorised as the __________ welding.
pressure
thermit
resistance
arc
resistance
The driving force for the sintering of a powder compact is
strain energy.
surface energy.
volume energy.
stacking fault energy.
surface energy.
The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the __________ of a boiler.
evaporative capacity
evaporation efficiency
thermal efficiency
steam load
evaporative capacity
Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that
pure oxygen has been used for combustion.
nitrogen percentage in the fuel is very high.
excess air has been used for combustion.
hydrogen is not present in the fuel.
excess air has been used for combustion.
A fluid is termed as the Newtonion fluid, when the shear stress is __________ the velocity gradient.
independent of
inversely proportional to
directly proportional to
none of these
directly proportional to
Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the
length of the pipe.
diameter of the pipe.
density of the fluid.
velocity of the fluid.
length of the pipe.
When the wet steam is throttled but still remains wet at the exit of the throttle valve, then its temperature & dryness fraction respectively
decreases & increases.
increases & increases.
increases & decreases.
decreases & decreases.
decreases & increases.
