Materials and Construction Flashcards
The behaviour of visco-elastic material is time dependent. This behaviour is common in __________ materials.
non-crystalline organic polymeric.
Coke oven regenerators are made of __________ bricks.
fire clay
Which of the following is universally employed as the low expansion metal in the bimetallic thermometer, which is an iron-nickel alloy containing 36% nickel and has very low co-efficient of expansion (l/20th of ordinary metals) ?
invar
Shock resisting steels should possess high
toughness
The purpose of nitriding the steel is to
harden its surface.
Ceramic recuperators are generally made of
silicon carbide.
Hammers and railway rails are normally made of
high carbon steel
Softness of silver can be converted into hardness by alloying it with small quantity of
copper & nickel
The addition of antimony in tin-based alloys improves its
deformation resistance.
The melleability 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 miximum malleability ?
Lead
The main purpose of galvanising iron sheets is to
prevent the action of water.
The impure iron (pig iron) that is tapped out from blast furnace contains about __________ percent carbon.
4
Invar used in thermocouples is an alloy of nickel and
iron
Nickel (56%) and molybdenum (17%) alloys are called
hastealloy C
Lead pipes are not safe for carrying drinking water because water containing dissolved oxygen attacks lead thereby forming poisonous Pb (OH)2. Lead pipes are readily corroded by
acetic acid
Constituents of stellite are
cobalt, chromium and tungsten.
Residual magnetism in steel for magnets is increased by the addition of
cobalt
Presence of nickel in steel improves its
corrosion resistance.
Cementite is
all (a), (b) and (c).
Acetylene gas holder is made of
steel
Sulphur melting pit in the sulphuric acid plant is made of
steel or cement-brick lined.
The hardest material just prior to diamond in Mho’s scale is
corrundum
Percentage elongation of a material is a measure of its
ductility
Chlorination of benzene is done to produce benzene hexachloride (a pesticide) in a photochemical reactor lined with
lead or glass
Heavy duty bearings are usually made of
white metal
Dielectric strength of a material is
its capacity to withstand high voltage.
Which of the following stainless steels is non-magnetic ?
Austenitic
18-4-1 high speed steel contains 18%, 4% and 1% respectively of
tungsten, chromium and vanadium
Aluminium as a material of construction suffers from the disadvantage of
rather low tensile strength.
Babbit metal used for bearings is a____base alloy.
tin
18/8 steel is a/an __________ stainless steel.
austenitic
Cast iron has very high
compressive strength
Liquid ammonia is shipped in __________ containers.
glass
Cermets are __________ materials.
refractory
Cast irons are generally specified by their
tensile strength
Austenitic manganese steel used for making jaws of crushing machines contains about __________ percent manganese.
12-14
White cast iron is not
malleable
Galvanised iron is
protected from rusting
German silver used for decorative purposes contains maximum percentage of
copper
The metals occuring at the lower most position in the electromotive series
resist corrosion very strongly.
German silver in an alloy of
copper, nickel and zinc.
A suitable material of construction to use with fuming sulphuric acid is
monel
Which of the following crystal structures characterises the austenitic stainless steel?
Face centred cubic
Caustic soda is produced in a mercury cell having anode and cathode made respectively of moving mercury and
graphite and moving mercury.
Addition of __________ in steel can help in increasing the depth of hardness.
tungsten
Which of the following has the highest compressive strength ?
High carbon steel
Zinc is not used
as an alloying element in various bronzes.
Refined acetic acid storage vessel are made of
aluminium
Addition of __________ to the steel helps in increasing the residual magnetism in steel used for making magnets.
cobalt
Constantan is an alloy of
Cu (55%) & Ni (45%).
Babbit metals used for making bearings are
tin or lead based alloys.
Pipes for bi-cycle frames are made of __________ steel.
cold rolled
Which of the following materials may prove unsuitable for handling acetic acid (glacial & anhydrous) at 40°C ?
Brass, cast iron, mild steel and tin.
Interchain forces are the weakest in case of
both rubber & elastomers
__________ possesses viscoelastic properties.
Rubber
Steel tower used for the storage of oleum
need not be lined.
Plastics are
non-biodegradable.
Acetaldehyde is produced by hydration of acetylene in a sulphuric acid solution of mercuric sulphate. Hydration tower is made of
rubber lined mild steel
Wood is corroded by
all (a), (b) and (c)
Brass is an alloy of
copper and zinc
Lead
can not be work hardened.
Photographic plates are coated with
silver halide
Cast iron has
elastic limit close to ultimate breaking strength.
Locomotive boiler tubes are made of __________ alloys.
arsenic copper
Slow and progressive deformation of a material with time under constant stress is called
creep
Which of the following heat treatment processes is used for softening the hardened material ?
Tempering
Which of the following mechanical properties of a material is most structure insensitive ?
Modulus of elasticity (young’s modulus).
Mercury is transported in metal containers made of
iron
Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C ?
Stainless steel
Which of the following has the least carbon percentage ?
Wrought iron
The range of Mho’s scale of hardness is from
l to10
Which of the following pairs of elements may form an alloy ?
Iron & carbon
SO3 is absorbed using H2SO4 in a
packed steel tower lined with acid proof bricks.
Carbon percentage in medium carbon steel is around
0.35 to 0.5
The preferred material of construction for storage tanks for 98% sulphuric acid is
lead
The fermentor used for the production of ethyl alcohol from molasses is made of
copper bearing steel
Super conductors are those substances, which
offer no resistance to current flow.
Cermets are used for making
both (a) & (b)
The formation of oxide film on a metal due to atmospheric exposure reduces its
creep limit
A hardened steel essentially contains
martensite
Which one contains the least percentage of carbon ?
Wrought iron
Thermal shield used in high powered nuclear reactor to protect the walls of the reactor from radiation damage is made of
steel
All materials obey Hooke’s law within elastic limit. When elastic limit is reached, the tensile strain
increases very quickly.
Silico-manganese steels (containing 0.7% Mn, 0.5% C and 2% Si)
are used for leaf and coiled springs.
Which of the following is not a copper based alloy with nickel ?
Inconel
Which of the following alloys does not contain nickel ?
Babbit metal
An elastic behaviour of materials is expressed in terms of
relaxation time
Pure nickel is
ferromagnetic at room temperature.
In drop forging process, the forging is done by dropping the __________ at high velocity.
die with hammer
Which of the following is not an alloy of copper and tin ?
Monel metal
__________ is never shipped in glass carboys.
Ammonia
Lead is
used as a shock absorber (in mattress form) between the foundation and steel framework of skyscrapper buildings.
Nitriding of steel is done (in electric furnace) at __________ °C.
510
Addition of 2% nickel in steel makes it suitable for making
boiler plates, rivets etc.
The softest material just next to talc in the Mhos scale is
gypsum
Fatigue strength of a material increases by
under stressing the specimen
Specify the material of construction suitable for handling concentrated HNO3 at 100°C.
High silicon iron, Kel-F and teflon
Aluminium storage vessel can be used to store
none of these
Silicone rubber is not resistant to the corrosive action of
both (b) and (c)
Which metal is protected by the layer of its own oxide ?
Aluminium
Failure of a material is termed as fatigue failure, if it fails below the yield point. The resistance to fatigue failure of a material is measured by the
endurance limit
Bog iron used for the adsorption of H2S from coke oven gas is
an intimate mixture of saw dust and iron dust (i.e. moist ferric hydroxide).
Wrought iron is a suitable material of construction for handling __________ solutions.
alkalis & alkaline
Steel rods are used in reinforced concrete to increase its __________ strength.
tensile
Corrosion involves exchange of electrons in __________ corrosion.
both (a) & (b)
Straight silicon steel (containing Si from 0.5 to 5%) because of their low hysterisis loss and high magnetic permeability are used for electrical appliances. Which of the following electrical appliances made of silicon steel contains maximum percentage of silicon (about 4%) ?
High frequency transformers.
Which of the following has the least value of ultimate tensile strength (UTS) ?
Cast iron
__________ does not contain tin as an alloying material.
Brass
A metallic alloy in general as compared to their pure metal components is
more corrosion resistant.
Pick out the wrong statement.
Wrought iron can not be easily forged and welded.
The increase in hardness of metal due to its cold working is termed as the __________ hardening.
work
Copper is dissolved from its ore by H2SO4 in a percolation tank made of
reinforced concrete lined with lead
Bearings subjected to light load are made of
phosphorous bronze
Softening of hardned steel is done by its
tempering
Maximum permissible sulphur content in steel is __________ percent.
0.055
Ceramic materials fabrication can not be done by
welding
Which has the maximum melting point out of the following ?
Wrought iron
Cast iron is
all (a), (b) & (c)
Which of the following has no effect on the carbide forming tendency in steels ?
Phosphorus
Approximate value of the modulus of elasticity for steel is about __________ x l06kg/cm2.
2
Carbon is present in steel wholly in the
combined form.
Carbon supply in pack carburising process is in the form of
charcoal
In SO3 absorber (Contact Process), packing material used is of
chemical stoneware
Presence of manganese in alloy steel improves its
abrasion resistance & toughness.
Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with
lead or acid-proof bricks
A material is called ‘ductile’, if it can be
drawn into wires.
A chemical change takes place when iron
rusts
Evaporator used for concentrating tomato juice is made of
stainless steel-glass lined
High carbon steel contains more than __________ percent carbon.
0.5
The main constituent of carborundum is __________ carbide.
silicon
For storing water and acid free benzol, use a __________ vessel.
steel
The chlorinator used in the manufacture of DDT is made of
glass lined steel
Reduction in the grain size reduces the __________ of the material.
creep resistance
Age hardening is concerned with
duralumin
Which of the following undergoes granular fracture ?
Steel
Ball bearings are normally made of __________ steel.
chrome
The electrical conductivity of a __________ decreases with rise in temperature.
metal/alloy
Which one occupies the lowermost position in the electromotive series of metals ?
Noble metals (Ag, Pt, Au)
Addition of nickel to copper improves its
hardness
Presence of even 0.005% of __________ in copper makes it highly brittle, rendering it useless for wire-drawing.
bismuth
High speed cutting tool steels contain about __________ percent of tungsten.
18-20
The ‘bomb’ in the bomb calorimeter is made of
molybdenum stainless steel
Which of the following is produced by condensation polymerisation ?
Bakelite
The crystal structure of most of the common metals is
cubic
Telfon (PTFE) is corroded by
none of these
Hastelloy C is a good material of construction in chemical process industry, since it is
light and resists attack by acids.
Mixing vessel used for the chlorination of methane to produce methyl chloride is made of
cast iron
The loss of strength in compression which occurs, when there is a gain of strength in tension due to over loading is called
Bauschinger effect.
Pick out the wrong statement.
Thermal conductivity of aluminium is higher than that of copper; hence it is increasingly used for utensil making.
The specific gravity of coal depends mainly on its __________ content.
ash
Carbon percentage is the same in cast iron and
pig iron
Pick out the wrong statement.
The ability of a material to fracture without appreciable deformation is called its ductility.
Which of the following has the highest density and the lowest melting point ?
Lead
In order to be called steel, an alloy should have iron percentage greater than
80
Nickel is a constituent of
monel metal
Soap kettle used in the production of laundry soap is made of
steel with top section nickel clad or stainless steel
Nickel made/clad equipments are suitable for handling
fruit juices, milk & its products and caustic soda solution.
Tubes of multiple effect evaporator used for concentration of sugar cane juice are made of
copper
In hot wire aneomometer used for gas flow measurement, the wire is normally made of
platinum
The heat treatment process to which castings and the steel balls produced by cold heading are subjected is
normalising
Mild steel is used for making
channels
Presence of 0.3 to 0.5% arsenic in copper increases its
tenacity & hardness
The heat treatment process applied to cold formed steel parts is
solution annealing
The largest consumption of zinc for alloys is in the making of
brasses
Plate and frame filter press is usually made of
cast iron
Ammonium chloride solution is stored/ treated in __________ vessels/pipes.
rubber or durmet-20 lined
Nickel and copper are the basic constituents of
monel metal
Copper has very low
tensile strength
Hardest material so far found is
Hardest material so far found is
Most suitable material of construction for the storage of concentrated nitric acid is
aluminium or chromium alloys (Cr > 18% for cold acid)
The most resistant material to alkaline corrosion is
nickel
Tin coating is not done by
vaporising
Stainless steel is not corroded by
nitric acid (10%).
__________ is added in stainless steel to prevent inter crystal corrosion.
Niobium
Nickel is a __________ material.
ferromagnetic
Babbit metal is not a
pure metal
Which of the following alloys does not contain nickel ?
Babbit metal
Which of the following is the lightest of engineering metals ?
Magnesium
Evaporators used in caustic soda recovery and production plant are made of
monel metal
With increase in carbide/graphite ratio in cast iron, its
both (a) and (b).
The fermentor used in the production of pencillin (by deep fermentation process) is made of
glass lined steel
Nickel (76%) and chromium (15%) alloys are termed as
inconel
Low carbon steels are those in which carbon percentage is around
0.1 to 0.35
White metal is an alloy of
none of these
The carbonating tower used in Solvay process of soda ash manufacture is made of
cast iron
For platinum thermocouples, lead wires are made of
copper & copper-nickel alloys.
High resistance electrical heating elements/wire are not made of
marageing steel
Cast irons are generally specified by their
tensile strength
Which one is remelted and poured into moulds to get cast iron ?
Pig iron
Wood metal is not used for making
storage tank for storing brine and caustic soda.
An ideal material of construction for the storage of 50% caustic soda solution would be
monel
Which of the following is the hardest ?
Austenite
Which of the following alloy steels is the most suitable for making gun barrels and projectiles ?
Nickel-chrome steelZircalloy used as a fuel cladding material in a nuclear reactor (thermal) is an alloy of zirconium
The process of heating the cold pressed metallic powder is called __________ in powder metallurgy.
sintering
Sulphuric acid pickling tanks are lined with
rubber
Valves in pipe size of 2” and under are normally made of
brass
Ceramic materials are
stronger in compression than in tension
Which is an amorphous material ?
Glass
In the Contact process of sulphuric acid manufacture, 98% acid cooler is made of
cast iron
Platinum and silver are corroded by
none of these
Zircalloy used as a fuel cladding material in a nuclear reactor (thermal) is an alloy of zirconium
tin, nickel, iron and chromium
Dead mild steel, which contains 0.10 to 0.15 percent carbon is used for making
flanges
Work hardening of a material
decreases its ductility.
The material used in the filament of electric bulbs is
tungsten
