1. Stress relaxation is- the phenomenon
(a) in which parts are not loaded
(b) in which stress remains constant on in-creasing load
(c) in which deformation tends to loosen the joint and produces a stress reduced
(d) stress reduces on increasing load
Ans: c
2. The elastic stress strain behaviour of rubber is
(a) linear
(b) non-linear
(c) plastic
(d) no fixed relationship
Ans: b
3. Isotropic materials are those which have the same
(a) elastic properties in all directions
(b) stresses induced in all directions
(c) thermal properties in all directions
(d) electric and magnetic properties in all directions
Ans: a
4. Recrystallization temperature is one
(a) at which crystals first start forming from molten metal when it is cooled
(b) at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated
(c) at which change of allotropic form takes place
(d) at which crystals grow bigger in size
Ans: b
5. Points of arrest for iron correspond to
(a) stages at which allotropic forms change
(b) stages at which further heating does not increase temperature for some time
(c) stages at which properties do not change with increase in temperature
(d) there is nothing like points of arrest
Ans: a
6. Delta iron occurs at temperature of
(a) room temperature
(b) above melting point
(c) between 1400°C and 1539°C
(c) between 910°C and 1400°C
Ans: c
7. A material is known as allotropic or polymorphic if it
(a) has a fixed structure under all conditions
(b) exists in several crystal forms at different temperatures
(c) responds to heat treatment
(d) has its atoms distributed in a random pattern
Ans: b
8. Super conduction by metals is observed in the temperature range of
(a) below 10°K
(b) above 100°K
(c) around 0°C
(d) around 100°C
Ans: a
9. Which of the following constituents of steels is softest and least strong
(a) austenite
(b) pearlite
(c) ferrite
(d) cementlte
Ans: c
10. Which of the following represents the allotropic forms of iron
(a) alpha iron, beta iron and gamma iron
(b) alpha iron and beta iron
(c) body centred cubic a-iron and face centred cubic a-iron
(d) alpha iron, gamma from and delta iron
(e) none of the above.
Ans: d
11. The following types of materials are usually the most ductile
(a) face-centred cubic lattice
(b) body-centred cubic lattice
(c) hexagonal close-packed lattice
(d) all of the above
Ans: a
12. Mild steel belongs to the following category
(a) low carbon steel
(b) medium carbon steel
(c) high carbon steel
(d) alloy steel
Ans: a
13. The ultimate tensile strength of low carbon steel by working at a high strain rate will
(a) decrease
(b) increase
(c) remain constant
(d) first increase and then decrease
Ans: b
14. Slow plastic defomiation of metals under a constant stress is known as
(a) creep
(b) fatigue
(c) endurance
(d) plastic deformation
Ans: a
15. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to l00°C will
(a) increase
(b) decrease
(c) remain same
(d) first increase and then decrease
Ans: a
16. The number of electrons in 1 cm3 of metal would be of the order of
(a) 1010
(b)TO16
(c) 1022
(d) 1040
Ans: c
17. Ductility of a material can be defined as
(a) ability to undergo large permanent deformations in compression
(b) ability to recover its original form
(c) ability to undergo large permanent deformations in tension
(d) all of the above
Ans: c
18. Malleability of a material can be defined as
(a) ability to undergo large permanent deformations in compression
(b) ability to recover its original form
(c) ability to undergo large permanent deformations in tension
(d) all of the above
Ans: a
19. In compression, a prism of brittle material will break
(a) by forming a bulge
(b) by shearing along oblique plane
(c) in direction perpendicular to application of load
(d) by crushing into thousands of pieces
Ans: b
20. The ability of a material to resist softening at high temperature is known as
(a) creep
(b) hot tempering
(c) hot hardness
(d) fatigue
Ans: c
21. The surface hardness of the following order is achieved by nitriding operation
(a) 600 VPN
(b) 1500 VPN
(c) 1000 to 1100 VPN
(d) 250 VPN (e) 2000 VPN.
Ans: c
22. Hardness of martensite is about
(a) RC 65
(b) RC 48
(c) RC 57
(d) RC 80
Ans: a
23. Weld decay is the phenomenon found with
(a) cast iron
(b) mild steel
(c) non-ferrous materials
(d) wrought iron
(e) stainless steel.
Ans: e
24. Materials after cold working are subjected to following process to relieve stresses
(a) hot working
(b) tempering
(c) normalising
(d) annealing
Ans: d
25. Which is false statement about normalizing. Normalizing is done to
(a) refine grain structure
(b) reduce segregation in casting
(c) improve mechanical properties
(d) induce stresses-
Ans: d
26. Vanadium in high speed steels
(a) promotes decarburisation
(b) provides high hot hardness
(c) forms very hard carbides and thus in-creases wear resistance
(d) promotes retention of austenite
Ans: c
27. Amorphous material is one
(a) in which atoms align themselves in a geometric pattern upon solidification
(b) in which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid
(c) which is not attacked by phosphorous
(d) which emits fumes on melting
Ans: b
28. Dislocations in materials refer to the following type of defect
(a) point defect
(b) line defect
(c) plane defect
(d) volumetric defect
Ans: b
29. An example of amorphous material is
(a) zinc
(b) lead
(c) silver
(d) glass
Ans: d
30. Which is false statement about tempering. Tempering is done to
(a) improve machinability
(b) improve ductility
(c) improve toughness
(d) release stresses
Ans: a
31. Which is false statement about case hardening. Case hardening is done by
(a) electroplating
(b) cyaniding
(c) induction hardening
(d) nitriding
Ans: a
32. Which of the following is the binding material in cemented carbides
(a) cobalt
(b) nickel
(c) vanadium
(d) iron
Ans: a
33. Chromium in steel
(a) improves wear resistance, cutting ability and toughness
(b) refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
(c) improves cutting ability and reduces hardenability
(d) gives ductility, toughness, tensile strength and anticorrosion properties
Ans: a
34. Manganese in steel increases its
(a) tensile strength
(b) hardness
(c) ductility
(d) fluidity.
Ans: a
35. Cemented carbide tools are not found to be suitable for cutting
(a) brass
(b) cast iron
(c) aluminium
(d) steel
Ans: d
36. Hardness of upper bainite (acicular structure) is about
(a) RC 65
(b) RC 48
(c) RC 57
(d) RC 80
Ans: b
37. Carbon in iron is an example of
(a) substitutional solution
(b) interstitial solid solution
(c) intermetallic compounds
(d) all of the above
Ans: b
38. Brass (alloy of copper and zinc) is an example of
(a) substitutional solid solution
(b) interstitial solid solution
(c) intermetallic compounds
(d) all of the above
Ans: a
39. Which is false statement about annealing. Annealing is done to
(a) relieve stresses
(b) harden steel slightly
(c) improve machining characteristic
(d) soften material
Ans: b
40. Argentite is the principal ore or raw material for
(a) aluminium
(b) tin
(c) zinc
(e) lead
(e) silver.
Ans: e
41. Hardness of lower bainite (tempered martensite) is about
(a) RC 65
(b) RC 48
(c) RC 57
(d) RC 80
Ans: c
42. The most effective inhibitor of grain growth, when added in small quantities is
(a) carbon
(b) vanadium
(c) manganese
(d) cobalt
Ans: b
43. Depth of hardness of steel is increased by addition of
(a) nickel
(b) chromium
(c) tungsten
(d) vanadium
Ans: b
44. Railway rails are normally made of
(a) mild steel
(b) alloy steel
(c) high carbon
(d) tungsten steel
Ans: c
45. Pick up the wrong statement
(a) aluminium in steel results in excessive grain growth
(b) manganese in steel induces hardness
(c) nickel and chromium in steel help in raising the elastic limit and improve the resilience and ductility
(d) tungsten in steels improves magnetic properties and hardenability
Ans: a
46. Pick up the wrong statement Nickel and chromium in steel help in
(a) providing corrosion resistance
(b) improving machining properties
(c) providing high strength at elevated temperatures
(d) raising the elastic limit
Ans: b
47. An important property of malleable cast iron in comparison to grey cast iron is the high
(a) compressive strength
(b) ductility
(c) carbon content
(d) hardness
Ans: b
48. Steel contains
(a) 80% or more iron
(b) 50% or more iron
(c) alloying elements like chromium, tungsten nickel and copper
(d) elements like phosphorus, sulphur and silicon in varying quantities
Ans: b
49. Carbon steel is
(a) made by adding carbon in steel
(b) refined from cast iron
(c) an alloy of iron and carbon with varying quantities of phosphorus and sulphur
(d) extensively used for making cutting tools
Ans: c
50. Annealing of white cast iron results in production of
(a) malleable iron
(b) nodular iron
(c) spheroidal iron
(d) grey iron
Ans: a
51. ‘Killed steels’ are those steels
(a) which are destroyed by burning
(b) which after their destruction are recycled to produce fresh steel
(c) which are deoxidised in the ladle with silicon and aluminium
(d) in which carbon is completely burnt
Ans: c
52. Hardness of steel depends on
(a) amount of carbon it contains
(b) the shape and distribution of the car-bides in iron
(c) method of fabrication
(d) contents of alloying elements
Ans: b
53. Maximum percentage of carbon in ferrite is
(a) 0.025%
(b) 0.06%
(c) 0.1%
(d) 0.25%
Ans: a
54. Maximum percentage of carbon in austenite is
(a) 0.025%
(b) 0.26%
(c) 0.8%
(d) 1.25%
(e) 1.7%.
Ans: e
55 Corrosion resistance of steel is increased by addition of
(a) chromium and nickel
(b) sulphur, phosphorus, lead
(c) vanadium, aluminium
(d) tungsten, molybdenum, vanadium, chromium
Ans: a
56. In which of the following cases, consideration of creep is important
(a) flywheel of steam engine
(b) cast iron pipes”
(c) cycle chains
(d) gas turbine blades
Ans: d
57. Pick up the wrong statement
(a) aluminium in steel results in excessive grain growth
(b) manganese in steel induces hardness
(c) nickel and chromium in steel help in raising the elastic limit and improve the resilience and ductility
(d) tungsten in steels improves magnetic properties and hardenability
Ans: a
58. Pick up the wrong statement Nickel and chromium in steel help in
(a) providing corrosion resistance
(b) improving machining properties
(c) providing high strength at elevated temperatures
(d) raising the elastic limit
Ans: b
59. Machining properties of steel are improved by adding
(a) sulphur, lead, phosphorous
(b) silicon, aluminium, titanium
(c) vanadium, aluminium
(d) chromium, nickel
Ans: a
60. Eutectoid steel contains following percentage of carbon
(a) 0.02%
(b) 0.3%
(c) 0.63%
(d) 0.8%
Ans: d
61. The basic constituents of Hastelloy are
(a) aluminium, copper etc.
(b) nickel, molybdenum etc.
(c) nickel, copper, etc.
(d) all of the above
Ans: b
62. Basic constituents of Monel metal are
(a) nickel, copper
(b) nickel, molybdenum
(c) zinc, tin, lead
(d) nickel, lead and tin
Ans: a
63. German silver is an alloy of
(a) silver and some impurities
(b) refined silver
(c) nickel, copper and zinc
(d) nickel and copper
Ans: c
64. Surveying tapes are made of a material having low coefficient of expansion and enough strength. The alloy used is
(a) silver metal
(b) duralumin
(c) Hastelloy
(d) monel metal
(e) invar.
Ans: e
65. Pure iron is the structure of
(a) ferrite
(b) pearlite
(c) anstenite
(d) ferrite and cementite
Ans: a
66. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
(a) 770°C
(b) 910°C
(c) 1050°C
(d) below recrystallisation temperature
Ans: a
67. Gamma iron exits at following temperature
(a) room temperature
(b) near melting point
(c) between 1400°C and 1539°C
Ans: d
68. Ferromagnetic alpha iron exists in temperature range of
(a) below 723°C
(b) 770 – 910°C
(c) 910-1440°C
(d) 1400-1539°C
Ans: a
69. Paramagnetic alpha iron changes to gamma iron at
(a) 770°C
(b) 910°C
(c) 1440°C
(d) 1539°C
Ans: b
70. A reversible change in the atomic structure of steel with corresponding change in the properties is known as
(a) molecular change
(b) physical change
(c) allotropic change
(d) solidus change
Ans: c
71. The molecules in a solid move
(a) in a random manner
(b) in a haphazard way
(c) in circular motion
(d) back and forth like tiny pendulums
Ans: d
72. The crystal structure of gamma iron is
(a) body centred cubic
(b) face centred cubic
(c) hexagonal close packed
(d) cubic structure
Ans: b
73. The crystal of alpha iron is
(a) body centred cubic
(b) face centred cubic
(c) hexagonal close packed
(d) cubic structure
Ans: a
74. The metallic structure of mild steel is
(a) body centred cubic
(b) face centred cubic
(c) hexagonal close packed
(d) cubic structure
Ans: a
75. For the allotropic forms of iron, the points of arrest are
(a) the points where no further change occurs
(b) constant for all metals
(c) the points where there is no further flow of metal
(d) the points of discontinuity
Ans: d
76. The percentage of carbon in pig iron varies from
(a) 0.1 to 1.2%
(b) 1.5 to 2.5%
(c) 2.5 to 4%
(d) 4 to 4.5%
Ans: d
77. The percentage of carbon in grey iron castings usually varies between
(a) 0.5 to 1%
(b) 1 – 2% (c) 2.5 to 4.5%
(d) 5 – 7%
Ans: c
78 Pig iron is the name given to
(a) raw material for blast furnace
(b) product of blast furnace made by reduction of iron ore
(c) iron containing huge quantities of carbon
(d) iron in molten form in the ladles
Ans: b
79. The unique property of cast iron is its high
(a) malleability
(b) ductility
(c) surface finish
(d) damping characteristics
Ans: d
80. Cast iron is characterised by minimum of following %age of carbon
(a) 0.2%
(b) 0.8%
(c) 1.3%
(d) 2%
Ans: d
81. In grey cast iron, carbon is present in the form of
(a) cementite
(b) free carbon
(c) flakes
(d) spheroids
Ans: c
82. In nodular iron, graphite is in the form of
(a) cementite
(b) free carbon
(C) flakes
(d) spheroids
Ans: d
83. In malleable iron, carbon is present in the form of
(a) cementite
(b) free carbon
(c) flakes
(d) spheroids
(e) nodular aggregates of graphite.
Ans: e
84. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
(a) 770°C
(b) 910°C
(c) 1050°C
(d) below recrystallisation temperature
Ans: a
85. Gamma iron exits at following temperature
(a) room temperature
(b) near melting point
(c) between 1400°C and 1539°C
Ans: d
86. Ferromagnetic alpha iron exists in temperature range of
(a) below 723°C
(b) 770 – 910°C
(c) 910-1440°C
(d) 1400-1539°C
Ans: a
87. Paramagnetic alpha iron changes to gamma iron at
(a) 770°C
(b) 910°C
(c) 1440°C
(d) 1539°C
Ans: b
88. A reversible change in the atomic structure of steel with corresponding change in the properties is known as
(a) molecular change
(b) physical change
(c) allotropic change
(d) solidus change
Ans: c
89. The molecules in a solid move
(a) in a random manner
(b) in a haphazard way
(c) in circular motion
(d) back and forth like tiny pendulums
Ans: d
90. The crystal structure of gamma iron is
(a) body centred cubic
(b) face centred cubic
(c) hexagonal close packed
(d) cubic structure
Ans: b
91. The crystal of alpha iron is
(a) body centred cubic
(b) face centred cubic
(c) hexagonal close packed
(d) cubic structure
Ans: a
92. A cold chisel is made of
(a) mild steel
(b) cast iron
(c) H.S.S.
(d) high carbon
Ans: d
93. An engineer’s hammer is made of
(a) cast iron
(b) forged steel
(c) mild steel
(d) high carbon steel
Ans: d
94. Inconel is an alloy of
(a) nickel, chromium and iron
(b) nickel, copper
(c) nickel, chromium
(d) nickel, zinc
Ans: a
95. By severely deforming a metal in a particular direction it becomes
(a) ductile
(b) malleable
(c) homogeneous
(d) isotropic
(e) anisotropic.
Ans: e
96. Solder is an alloy consisting of
(a) tin, antimony, copper
(b) tin and copper
(c) tin and lead
(d) lead and zinc
Ans: b
97. Cyaniding is the process of
(a) dipping steel in cyanide bath
(b) reacting steel surface with cyanide salts
(c) adding carbon and nitrogen by heat treatment of steel to increase its surface hardness
(d) obtaining cyanide salts
Ans: c
98. Induction hardening is the process of
(a) hardening surface of workpiece to ob-tain hard and wear resistant surface
(b) heating and cooling rapidly
(c) increasing hardness throughout
(d) inducing hardness by continuous process
Ans: a
99. The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as
(a) hysteresis
(b) creep
(c) visco elasticity
(d) Boeschinger effect
Ans: d
100. Process of austempering results in
(a) formation of bainite structure
(b) carburised structure
(c) martenistic structure
(d) lamellar layers of carbide distributed throughout the structure
Ans: a