Materials and Construction Flashcards
(160 cards)
1
Q
The behaviour of visco-elastic material is time dependent. This behaviour is common in __________ materials.
A
non-crystalline organic polymeric.
2
Q
Coke oven regenerators are made of __________ bricks.
A
fire clay
3
Q
which is an iron-nickel alloy containing 36% nickel and has very low co-efficient of expansion (l/20th of ordinary metals) ?
A
Invar
4
Q
Shock resisting steels should possess high
A
toughness
5
Q
The purpose of nitriding the steel is to
A
harden its surface.
6
Q
Ceramic recuperators are generally made of
A
silicon carbide.
7
Q
Hammers and railway rails are normally made of
A
high carbon steel
8
Q
Softness of silver can be converted into hardness by alloying it with small quantity of
A
copper & nickel
9
Q
The addition of antimony in tin-based alloys improves its
A
deformation resistance.
10
Q
Which of the following materials has the maximum malleability ?
A
Lead
11
Q
The main purpose of galvanising iron sheets is to
A
prevent the action of water.
12
Q
The impure iron (pig iron) that is tapped out from blast furnace contains about __________ percent carbon.
A
4
13
Q
Invar used in thermocouples is an alloy of nickel and
A
iron
14
Q
Nickel (56%) and molybdenum (17%) alloys are called
A
hastealloy C
15
Q
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
A
acetic acid
16
Q
Constituents of stellite are
A
cobalt, chromium and tungsten.
17
Q
Residual magnetism in steel for magnets is increased by the addition of
A
cobalt
18
Q
Presence of nickel in steel improves its
A
corrosion resistance.
19
Q
Acetylene gas holder is made of
A
steel
20
Q
Sulphur melting pit in the sulphuric acid plant is made of
A
steel or cement-brick lined.
21
Q
The hardest material just prior to diamond in Mho’s scale is
A
corrundum
22
Q
Percentage elongation of a material is a measure of its
A
ductility
23
Q
Chlorination of benzene is done to produce benzene hexachloride (a pesticide) in a photochemical reactor lined with
A
lead or glass
24
Q
Heavy duty bearings are usually made of
A
white metal
25
Which of the following stainless steels is non-magnetic ?
Austenitic
25
Dielectric strength of a material is
its capacity to withstand high voltage.
26
18-4-1 high speed steel contains 18%, 4% and 1% respectively of
tungsten, chromium and vanadium
27
Aluminium as a material of construction suffers from the disadvantage of
rather low tensile strength.
28
Babbit metal used for bearings is a____base alloy.
tin
29
Cast iron has very high
compressive strength
30
Liquid ammonia is shipped in __________ containers.
glass
31
Cermets are __________ materials.
refractory
32
Austenitic manganese steel used for making jaws of crushing machines contains about __________ percent manganese.
12-14
33
White cast iron is not
malleable
34
German silver used for decorative purposes contains maximum percentage of
copper
35
The metals occuring at the lower most position in the electromotive series
resist corrosion very strongly.
36
German silver in an alloy of
copper, nickel and zinc.
37
A suitable material of construction to use with fuming sulphuric acid is
monel
38
Which of the following crystal structures characterises the austenitic stainless steel?
Face centred cubic
39
Addition of __________ in steel can help in increasing the depth of hardness.
tungsten
40
Which of the following has the highest compressive strength ?
High carbon steel
41
Zinc is not used
as an alloying element in various bronzes.
42
Refined acetic acid storage vessel are made of
aluminium
43
Addition of __________ to the steel helps in increasing the residual magnetism in steel used for making magnets.
cobalt
44
Constantan is an alloy of
Cu (55%) & Ni (45%).
45
Pipes for bi-cycle frames are made of __________ steel.
cold rolled
46
Steel tower used for the storage of oleum
need not be lined.
47
Hydration tower of acetaldehyde is made of
rubber lined mild steel
48
Brass is an alloy of
copper and zinc
49
Photographic plates are coated with
silver halide
50
Cast iron has
elastic limit close to ultimate breaking strength.
51
Locomotive boiler tubes are made of __________ alloys.
arsenic copper
52
Slow and progressive deformation of a material with time under constant stress is called
creep
53
Which of the following heat treatment processes is used for softening the hardened material ?
Tempering
54
Which of the following mechanical properties of a material is most structure insensitive ?
Modulus of elasticity (young's modulus).
55
Mercury is transported in metal containers made of
iron
56
Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C ?
Stainless steel
57
Which of the following has the least carbon percentage ?
Wrought iron
58
SO3 is absorbed using H2SO4 in a
packed steel tower lined with acid proof bricks.
59
The preferred material of construction for storage tanks for 98% sulphuric acid is
lead
60
The fermentor used for the production of ethyl alcohol from molasses is made of
copper bearing steel
61
Super conductors are those substances, which
offer no resistance to current flow.
62
The formation of oxide film on a metal due to atmospheric exposure reduces its
creep limit
63
A hardened steel essentially contains
martensite
64
Thermal shield used in high powered nuclear reactor to protect the walls of the reactor from radiation damage is made of
steel
65
All materials obey Hooke's law within elastic limit. When elastic limit is reached, the tensile strain
increases very quickly.
66
Silico-manganese steels (containing 0.7% Mn, 0.5% C and 2% Si)
are used for leaf and coiled springs.
67
Pure nickel is
ferromagnetic at room temperature.
68
In drop forging process, the forging is done by dropping the __________ at high velocity.
die with hammer
69
__________ is never shipped in glass carboys.
Ammonia
70
Nitriding of steel is done (in electric furnace) at __________ °C.
510
71
Addition of 2% nickel in steel makes it suitable for making
boiler plates, rivets etc.
72
The softest material just next to talc in the Mhos scale is
gypsum
73
Fatigue strength of a material increases by
under stressing the specimen
74
Specify the material of construction suitable for handling concentrated HNO3 at 100°C.
High silicon iron, Kel-F and teflon
75
Silicone rubber is not resistant to the corrosive action of
both sulphuric acid (10%) and sulphuric acid (95%)
76
Which metal is protected by the layer of its own oxide ?
Aluminium
77
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
78
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).
79
Wrought iron is a suitable material of construction for handling __________ solutions.
alkalis & alkaline
80
Steel rods are used in reinforced concrete to increase its __________ strength.
tensile
81
Corrosion involves exchange of electrons in __________ corrosion.
chemical & electrochemical
82
Which of the following has the least value of ultimate tensile strength (UTS) ?
Cast iron
83
__________ does not contain tin as an alloying material.
Brass
84
A metallic alloy in general as compared to their pure metal components is
more corrosion resistant.
85
The increase in hardness of metal due to its cold working is termed as the __________ hardening.
work
86
Copper is dissolved from its ore by H2SO4 in a percolation tank made of
reinforced concrete lined with lead
87
Bearings subjected to light load are made of
phosphorous bronze
88
Ceramic materials fabrication can not be done by
welding
89
Which has the maximum melting point out of the following ?
Wrought iron
90
Which of the following has no effect on the carbide forming tendency in steels ?
Phosphorus
91
Approximate value of the modulus of elasticity for steel is about __________ x l0^6 kg/cm2.
2
92
Carbon is present in steel wholly in the
combined form.
93
Carbon supply in pack carburising process is in the form of
charcoal
94
In SO3 absorber (Contact Process), packing material used is of
chemical stoneware
95
Presence of manganese in alloy steel improves its
abrasion resistance & toughness.
96
Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with
lead or acid-proof bricks
97
A material is called 'ductile', if it can be
drawn into wires.
98
High carbon steel contains more than __________ percent carbon.
0.5
99
The main constituent of carborundum is __________ carbide.
silicon
100
For storing water and acid free benzol, use a __________ vessel.
steel
101
The chlorinator used in the manufacture of DDT is made of
glass lined steel
102
Reduction in the grain size reduces the __________ of the material.
creep resistance
103
Age hardening is concerned with
duralumin
104
Which of the following undergoes granular fracture ?
Steel
105
Ball bearings are normally made of __________ steel.
chrome
106
The electrical conductivity of a __________ decreases with rise in temperature.
metal/alloy
107
electromotive series, starting with the most easily oxidized
lithium, potassium, calcium, sodium, magnesium, aluminum, zinc, chromium, iron, cobalt, nickel, lead, hydrogen, copper, mercury, silver, platinum, gold
108
Carbon in steel
Increases:
- strength
- hardness
- mechanical resistance
- tensile strength
Decreases:
- malleability
- ductility
- toughness
109
Chromium in steel
(12% wt)
Increases:
- stainless feature (bright oxide layer it forms)
- hardness (carbides)
- tensile strength
Decreases:
- ductility
110
Nickel in steel
(5% wt)
Increases:
- hardness
- strength
111
Manganese
Increases:
- strength
- malleability (react with sulfur)
- quenching depth
- hardness
- weldability
Decreases:
- ductility
112
Sulfur in steel
(undesirable alloying element - makes it brittle)
Increases:
- free cutting properties
113
Silicium in steel
(Oxygen and degassing agent during production)
Increases:
- fluidity
- magnetic properties
- heat resistance
- hardenability
Decreases:
- surface quality
114
Molybdenum in steel
(to prevent brittleness)
(used in tool steels)
Increases:
- heat resistance
- effects of other elements (popular to be used with others)
- hardness
115
Vanadium in steel
(prevent grain coarsening)
(used in tool steels)
Increases:
- strength
- hardness
- wear resistance
116
Tungsten in steel
(popular in tool steels and high speed steels)
Increases:
- toughness
- hardness
- wear resistance
- cutting efficiency (in hot temp)
117
Cobalt in steels
Increases:
- strength
- heat resistance
118
Aluminum in steels
(as deoxidizer)
Increase:
- aging resistance
Decrease:
- growth of austenite grains
119
Phosphorus in steel
(undesirable - makes it brittle)
Increases:
- hardenability
Decreases:
- ductility
120
Copper in steel
(max 0.5% wt)
Increases:
- corrosion resistance
- hardness
Decreases:
- ductility
121
Nitrogen in steel
(facilitates machining process)
Increases:
- strength
- hardness (by forming nitride)
- fragility
122
Presence of even 0.005% of __________ in copper makes it highly brittle, rendering it useless for wire-drawing.
bismuth
123
High speed cutting tool steels contain about __________ percent of tungsten.
18-20
124
The 'bomb' in the bomb calorimeter is made of
molybdenum stainless steel
125
Which of the following is produced by condensation polymerisation ?
Bakelite
126
Hastelloy C is a good material of construction in chemical process industry, since it is
light and resists attack by acids.
127
Mixing vessel used for the chlorination of methane to produce methyl chloride is made of
cast iron
128
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.
129
Hastelloy C is a good material of construction in chemical process industry, since it is
light and resists attack by acids.
130
Mild steel is used for making
channels
131
The heat treatment process applied to cold formed steel parts is
solution annealing
132
The largest consumption of zinc for alloys is in the making of
brasses
133
Plate and frame filter press is usually made of
cast iron
134
Ammonium chloride solution is stored/ treated in __________ vessels/pipes.
rubber or durmet-20 lined
135
Most suitable material of construction for the storage of concentrated nitric acid is
aluminium or chromium alloys (Cr > 18% for cold acid)
136
The most resistant material to alkaline corrosion is
nickel
137
Tin coating is not done by
vaporising
138
Stainless steel is not corroded by
nitric acid (10%).
139
Nickel is a __________ material.
ferromagnetic
140
The fermentor used in the production of pencillin (by deep fermentation process) is made of
glass lined steel
141
Nickel (76%) and chromium (15%) alloys are termed as
inconel
142
The carbonating tower used in Solvay process of soda ash manufacture is made of
cast iron
143
For platinum thermocouples, lead wires are made of
copper & copper-nickel alloys.
144
High resistance electrical heating elements/wire are not made of
marageing steel
145
An ideal material of construction for the storage of 50% caustic soda solution would be
monel
146
The process of heating the cold pressed metallic powder is called __________ in powder metallurgy.
sintering
147
Sulphuric acid pickling tanks are lined with
rubber
148
Valves in pipe size of 2" and under are normally made of
brass
149
Which is an amorphous material ?
Glass
150
In the Contact process of sulphuric acid manufacture, 98% acid cooler is made of
cast iron
151
section 5
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