Question 1
A material is said to be allotropic, if it has
A. fixed structure at all temperatures
B. atoms distributed in random pattern
C. different crystal structures at different temperatures
D. any one of the above
View Answer
Question 2
A small percentage of boron is added to steel in order to
A. increase hardenability
B. reduce machinability
C. increase wear resistance
D. increase endurance strength
View Answer
Question 3
An alloy steel which is work hardenable and which is used to make the blades of bulldozers, bucket wheel excavators and other earth moving equipment contain iron, carbon and
A. chromium
B. silicon
C. manganese
D. magnesium
View Answer
Question 4
An eutectoid steel consists of
A. wholly pearlite
B. wholly austenite
C. pearlite and ferrite
D. pearlite and cementite
View Answer
Question 5
Brass is an alloy of
A. copper and zinc
B. copper and tin
C. copper, tin and zinc
D. none of these
View Answer
Question 6
Cast iron is a
A. ductile material
B. malleable material
C. brittle material
D. tough material
View Answer
Question 7
Cast iron is manufactured in
A. blast furnace
B. cupola
C. open hearth furnace
D. bessemer converter
View Answer
Question 8
Closed packed hexagonal space lattice is found in
A. zinc, magnesium, cobalt, cadmium, antimony and bismuth
B. gamma-iron, aluminium, copper, lead, silver and nickel
C. alpha-iron, tungsten, chromium and molybdenum
D. none of the above
View Answer
Question 9
Crystal structure of a material is, generally, examined by
A. naked eye
B. optical microscope
C. metallurgical microscope
D. X-ray techniques
View Answer
Question 10
Dye penetrant method is generally used to locate
A. core defects
B. surface defects
C. superficial defects
D. temporary defects
View Answer
Question 11
Ferrite and pearlite makes the steel soft and ductile.
A. Agree
B. Disagree
View Answer
Question 12
Free carbon in iron makes the metal
A. soft and gives a coarse grained crystalline structure
B. soft and gives a fine grained crystalline structure
C. hard and gives a coarse grained crystalline structure
D. hard and gives a fine grained crystalline structure
View Answer
Question 13
Haematite iron ore contains iron about
A. 30%
B. 45%
C. 55%
D. 70%
View Answer
Question 14
In full annealing, the hypo-eutectoid steel is heated from 30° C to 50° C above the upper critical temperature and then cooled
A. in still air
B. slowly in the furnace
C. suddenly in a suitable cooling medium
D. any one of these
View Answer
Question 15
Iron ore is, usually, found in the form of
A. oxides
B. carbonates
C. sulphides
D. all of these
View Answer
Question 16
Iron-carbon alloys containing 1.7 to 4.3% carbon are known as
A. eutectic cast irons
B. hypo-eutectic cast irons
C. hyper-eutectic cast irons
D. none of these
View Answer
Question 17
Malleable cast iron is produced
A. by adding magnesium to molten cast iron
B. by quick cooling of molten cast iron
C. from white cast iron by annealing process
D. none of these
View Answer
Question 18
Nimonic contains __________ percentage of nickel as that of Inconel.
A. same
B. less
C. more
View Answer
Question 19
Nodular cast iron is produced by adding __________ to the molten cast iron.
A. nickel
B. chromium
C. copper
D. magnesium
View Answer
Question 20
Shock resisting steels should have
A. low wear resistance
B. low hardness
C. low tensile strength
D. toughness
View Answer
Question 21
Silicon when added to copper improves
A. machinability
B. hardness
C. hardness and strength
D. strength and ductility
View Answer
Question 22
Smelting is the process of
A. removing the impurities like clay, sand etc. from the iron ore by washing with water
B. expelling moisture, carbon dioxide, sulphur and arsenic from the iron ore by heating in shallow kilns
C. reducing the ore with carbon in the presence of a flux
D. all of the above
View Answer
Question 23
Specify the sequence correctly
A. Grain growth, recrystallisation, stress relief
B. Stress relief, grain growth, recrystallisation
C. Stress relief, recrystallisation, grain growth
D. Grain growth, stress relief, recrystallisation
View Answer
Question 24
The ability of a material to absorb energy in the plastic range is called
A. resilience
B. creep
C. fatigue strength
D. toughness
View Answer
Question 25
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
A. chromium
B. nickel
C. vanadium
D. cobalt
View Answer
Question 26
The charge is fed into the blast furnace through the
A. stack
B. throat
C. bosh
D. tuyers
View Answer
Question 27
The coke in the charge of blast furnace
A. controls the grade of pig iron
B. acts as an iron-bearing mineral
C. supplies heat to reduce ore and melt the iron
D. forms a slag by combining with impurities
View Answer
Question 28
The cupola is used to manufacture
A. pig iron
B. cast iron
C. wrought iron
D. steel
View Answer
Question 29
The dieing down of a white flame during the operation of a bessemer converter indicates that the air is burning out silicon and manganese.
A. Yes
B. No
View Answer
Question 30
The electric process of steel making is especially adopted to
A. alloy and carbon tool steel
B. magnet steel
C. high speed tool steel
D. all of these
View Answer
Question 31
The hardness and tensile strength in austenitic stainless steel can be increased by
A. hardening and cold working
B. normalising
C. martempering
D. full annealing
View Answer
Question 32
The hardness is the property of a material due to which it
A. can be drawn into wires
B. breaks with little permanent distortion
C. can cut another metal
D. can be rolled or hammered into thin sheets
View Answer
Question 33
The hardness of steel increases if it contains
A. pearlite
B. ferrite
C. cementite
D. martensite
View Answer
Question 34
The heat treatment process used for softening hardened steel is
A. carburising
B. normalising
C. annealing
D. tempering
View Answer
Question 35
The lower critical point for all steels is
A. 600°C
B. 700°C
C. 723°C
D. 913°C
View Answer
Question 36
The lower critical temperature
A. decreases as the carbon content in steel increases
B. increases as the carbon content in steel increases
C. is same for all steels
D. depends upon the rate of heating
View Answer
Question 37
The material in which the atoms are arranged regularly in some directions but not in others, is called
A. amorphous material
B. mesomorphous material
C. crystalline material
D. none of these
View Answer
Question 38
The percentage of carbon in cast iron varies from
A. 0.1 to 0.5
B. 0.5 to 1
C. 1 to 1.7
D. 1.7 to 4.5
View Answer
Question 39
The property of a material due to which it breaks with little permanent distortion, is called
A. brittleness
B. ductility
C. malleability
D. plasticity
View Answer
Question 40
The quenching of steel from the upper critical point results in a fine grained structure.
A. Agree
B. Disagree
View Answer
Question 41
The steel produced by bessemer or open hearth process is __________ to that produced by L-D process.
A. superior
B. inferior
View Answer
Question 42
The type of space lattice found in gamma-iron is
A. face centred cubic space lattice
B. body centred cubic space lattice
C. close packed hexagonal space lattice
D. none of these
View Answer
Question 43
The unit cells
A. contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal
B. have the same orientation and their similar faces are parallel
C. may be defined as the smallest parallelopiped which could be transposed in three coordinate directions to build up the space lattice
D. all of the above
View Answer
Question 44
Thermoplastic materials are those materials which
A. are formed into shape under heat and pressure and results in a permanently hard product
B. do not become hard with the application of heat and pressure and no chemical change occurs
C. are flexible and can withstand considerable wear under suitable conditions
D. are used as a friction lining for clutches and brakes
View Answer
Question 45
Tungsten when added to steel __________ the critical temperature.
A. does not effect
B. lowers
C. raises
View Answer
Question 46
When the steel is normalised, its
A. yield point increases
B. ductility decreases
C. ultimate tensile strength increases
D. all of these
View Answer
Question 47
Which of the following has a fine gold colour and is used for imitation jewellery?
A. Silicon bronze
B. Aluminium bronze
C. Gun metal
D. Babbit metal
View Answer
Question 48
Which of the following material has maximum ductility?
A. Mild steel
B. Copper
C. Nickel
D. Aluminium
View Answer
Question 49
Which of the following process of steel making is in operation at Tata Iron and Steel Works, Jamshedpur?
A. Bessemer process
B. Open hearth process
C. Duplex process
D. Electric process
View Answer
Question 50
White cast iron has a high tensile strength and a low compressive strength.
A. Yes
B. No
View Answer
Answer: Option B
Explanation:
White cast iron has a low tensile strength and a high compressive strength.
Source: https://en.wikipedia.org/wiki/Cast_iron#Table_of_comparative_qualities_of_cast_irons
Question 51
Bronze is an alloy of
A. Copper and zinc
B. Copper and tin
C. Copper, tin and zinc
D. None of these
View Answer
Answer: Option B
Explanation:
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.
Question 52
Manganese is added in low carbon steel to
A. Make the steel tougher and harder
B. Raise the yield point
C. Make the steel ductile and of good bending qualities
D. All of the above
View Answer
Answer: Option C
Explanation:
The effect of manganese in improving the mechanical properties of steel depends on its carbon content. Manganese also reduces the critical cooling rate during hardening, meaning it increases the hardenability of steel. Its effect on hardenability is higher than other alloying elements. Hadfield steel is recognized for its ability to be work-hardened due to the addition of 10% to 14% of manganese.
Question 53
The elastic stress strain behavior of rubber is
A. Linear
B. Nonlinear
C. Plastic
D. No fixed relationship
View Answer
Answer: Option B
Explanation:
The most common example of this kind of material is rubber, whose stress-strain relationship can be defined as non-linearly elastic, isotropic, in compressible and generally independent of strain rate. Hyper elasticity provides a means of modeling the stress–strain behavior of such materials
Question 54
The following element can't impart high strength at elevated temperature
A. Manganese
B. Magnesium
C. Nickel
D. Silicon
View Answer
Answer: Option B
Explanation:
The strength, hardness, and modulus of elasticity of magnesium-base materials decrease with increasing temperature. Also, the elongation increases with rising temperature up to just below the melting point where it drops to nearly zero
Question 55
In process annealing, the hypo eutectoid steel is
A. Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
B. Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
C. Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
D. Heated below or closes to the lower critical temperature and then cooled slowly
View Answer
Answer: Option D
Explanation:
In process annealing, the hypo eutectoid steel isHeated below or closes to the lower critical temperature and then cooled slowly
Question 56
In a hardening process, the hypo-eutectoid steel is
A. Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
B. Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
C. Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
D. Heated below or closes to the lower critical temperature and then cooled slowly
View Answer
Answer: Option B
Explanation:
In a hardening process, the hypo-eutectoid steel is Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Question 57
The temperature required for full annealing in hypereutectoid steel is
A. 30° C to 50° C above upper critical temperature
B. 30° C to 50° C below upper critical temperature
C. 30° C to 50° C above lower critical temperature
D. 30° C to 50° C below lower critical temperature
View Answer
Answer: Option C
Explanation:
Full annealing is the process of slowly raising the temperature about 50 ºC (122 ºF) above the Austenitic temperature line A3 or line ACM in the case of Hypoeutectoid steels (steels with < 0.77% Carbon) and 50 ºC (122 ºF) into the Austenite-Cementite region in the case of Hypereutectoid steels (steels with > 0.77% Carbon).
Question 58
Duralumin contains
A. 3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
B. 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
C. 4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
D. 5 to 6% tin, 2 to 3% copper and rest aluminium
View Answer
Answer: Option A
Explanation:
In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium. For instance, Duraluminium 2024 consists of 91-95% aluminium, 3.8-4.9% copper, 0.3-0.9% manganese, 1.2-1.8% magnesium, <0.5% iron, <0.5% silicon, <.0.25% zinc, <0.15% titanium, <0.10% chromium and no more than 0.15% of other elements together.
Question 59
Admiralty gun metal contains
A. 63 to 67% nickel and 30% copper
B. 88% copper, 10% tin and rest zinc
C. Alloy of tin, lead and cadmium
D. Iron scrap and zinc
View Answer
Answer: Option B
Explanation:
Admiralty gun metal contains 88% copper, 10% tin and rest zinc
Question 60
Gun metal contains
A. 70% copper and 30% zinc
B. 90% copper and 10% tin
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 78% copper and rest tin
View Answer
Answer: Option C
Explanation:
Gun metal contains 85 - 92% copper and rest tin with little lead and nickel
Question 61
Which is the false statement about wrought iron? It has
A. High resistance to rusting and corrosion
B. High ductility
C. Ability of hold protective coating
D. Uniform strength in all directions
View Answer
Answer: Option D
Explanation:
Physical properties of wrought iron are listed below:Soft and ToughDuctileHight tensile StrengthHigh compressive strengthEasily forged and weldable
Question 62
Foundry crucible is made of
A. Mild steel
B. German silver
C. Lead
D. Graphite
View Answer
Answer: Option D
Explanation:
A crucible is a pot that is used to keep metals for melting in a furnace. Furnace crucibles are designed to withstand the highest temperatures encountered in the metal casting works. and it is made of graphite.
Question 63
Perminvar alloy having constant permeability is an alloy of
A. Nickel, copper and iron
B. Nickel, copper and zinc
C. Copper, nickel and antimony
D. Iron, zinc and bismuth
View Answer
Answer: Option A
Explanation:
Perminvar alloy having constant permeability is an alloy of Nickel, copper and iron
Question 64
Tungsten 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 anti-corrosion properties
View Answer
Answer: Option B
Explanation:
Tungsten in steel Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
Question 65
Body centered cubic space lattice is found in
A. Zinc, magnesium, cobalt, cadmium, antimony and bismuth
B. Gamma iron, aluminium, copper, lead, silver and nickel
C. Alpha iron, tungsten, chromium and molybdenum
D. None of the above
View Answer
Answer: Option C
Explanation:
Body-centered cubic space lattice is found in Alpha iron, tungsten, chromium and molybdenumBody-centered cubic lattice (bcc or cubic-I), like all lattices, has lattice points at the eight corners of the unit cell plus additional points at the center of the cell.
Question 66
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
View Answer
Answer: Option C
Explanation:
Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. and The surface hardness is achieved by nitriding operation at 1000 to 1100 VPN
Question 67
Slow plastic deformation of metals under a constant stress is known as
A. Creep
B. Fatigue
C. Endurance
D. Plastic deformation
View Answer
Answer: Option A
Explanation:
creep is the tendency of a solid material to move slowly or deform permanently under the influence of mechanical stresses.
Question 68
Which of the following display properties similar to that of steel?
A. Blackheart cast iron
B. Whiteheart cast iron
C. Both (A) and (B)
D. None of these
View Answer
Answer: Option C
Explanation:
Blackheart cast iron. and Whiteheart cast iron has similar properties to steel
Question 69
When low carbon steel is heated up to upper critical temperature
A. There is no change in grain size
B. The average grain size is a minimum
C. The grain size increases very rapidly
D. The grain size first increases and then decreases very rapidly
View Answer
Answer: Option B
Explanation:
When low carbon steel is heated up to upper critical temperature The average grain size is a minimum
Question 70
When low carbon steel is heated up to lower critical temperature
A. There is no change in grain size
B. The average grain size is a minimum
C. The grain size increases very rapidly
D. The grain size first increases and then decreases very rapidly
View Answer
Answer: Option A
Explanation:
When low carbon steel is heated up to lower critical temperature There is no change in grain size
Question 71
The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
A. 770°C
B. 910°C
C. 1050°C
D. Below recrystallization temperature
View Answer
Answer: Option A
Explanation:
Below 773 °C (1,423 °F), alpha iron becomes ferromagnetic (i.e., capable of being permanently magnetized), indicating a change in electronic structure but no change in crystal structure.
Question 72
The unit cells
A. Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal
B. Have the same orientation and their similar faces are parallel
C. May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice
D. All of the above
View Answer
Answer: Option D
Explanation:
1.The unit cells Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal2. The unit cells Have the same orientation and their similar faces are parallel3. The unit cells May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice
Question 73
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
View Answer
Answer: Option B
Explanation:
Pig iron is the intermediate product extracted from iron ore in a blast furnace. Pig iron is used as raw material in steel making. Pig iron gets its name from the old fashioned method of casting the iron into moulds arranged in sand beds so that they could be fed from a common runner
Question 74
Which of the following impurity in cast iron promotes graphite nodule formation and increases the fluidity of the molten metal?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
View Answer
Answer: Option A
Explanation:
Silicon is the impurity in cast iron which promotes graphite nodule formation and increases the fluidity of the molten metal.
Question 75
Wrought iron is
A. Hard
B. High in strength
C. Highly resistant to corrosion
D. Heat treated to change its properties
View Answer
Answer: Option C
Explanation:
Wrought iron is soft, ductile, magnetic, and has high elasticity and tensile strength. It can be heated and reheated and worked into various shapes.
Question 76
Which of the following alloys does not have copper as one of the constituents?
A. Delta metal
B. Monel metal
C. Constantan
D. Nichrome
View Answer
Answer: Option D
Explanation:
Nichrome is a nickel-chromium alloy with non-magnetic properties.
Question 77
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. Invar
View Answer
Answer: Option D
Explanation:
Invar is an alloy of iron and nickel with a negligible coefficient of expansion,.and it is used in the making of clocks and scientific instruments like surveying tapes
Question 78
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
View Answer
Answer: Option B
Explanation:
a prism of brittle material when subjected to stress, it breaks without significant plastic deformation.Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound.
Question 79
Hardness of lower bainite (tempered martensite) is about
A. RC 65
B. RC 48
C. RC 57
D. RC 80
View Answer
Answer: Option C
Explanation:
Hardness of lower bainite (tempered martensite) is about RC 57
Question 80
The compressive strength of cast iron is __________that of its tensile strength.
A. Equal to
B. Less than
C. More than
D. None of these
View Answer
Answer: Option C
Explanation:
The compressive strength of cast iron is more than that of its tensile strength.
Question 81
Chromium when added to steel _________ the tensile strength.
A. Does not effect
B. Decreases
C. Increases
D. None of these
View Answer
Answer: Option C
Explanation:
Chromium when added to steel to Increases the tensile strength.
Question 82
White metal contains
A. 63 to 67% nickel and 30% copper
B. 88% copper and 10% tin and rest zinc
C. Alloy of tin, lead and cadmium
D. Silver and chromium
View Answer
Answer: Option C
Explanation:
White metal contains Alloy of tin, lead and cadmium
Question 83
Which of the following has a fine gold colour and is used for imitation jewellery?
A. Silicon bronze
B. Aluminium bronze
C. Gun metal
D. Babbitt metal
View Answer
Answer: Option B
Explanation:
Aluminium bronze is used for imitation jewellery
Question 84
Large forgings, crank shafts, axles normally contain carbon up to
A. 0.05 to 0.20%
B. 0.20 to 0.45%
C. 0.45 to 0.55%
D. 0.55 to 1.0%
View Answer
Answer: Option C
Explanation:
Large forgings, crank shafts, axles made from cast iron or forged steel. Steel is usually used in high loading situations, and this steel contains carbon up to 0.45 to 0.55%.
Question 85
Cemented carbide tools are not found to be suitable for cutting
A. Brass
B. Cast iron
C. Aluminium
D. Steel
View Answer
Answer: Option D
Explanation:
Cemented carbide tools are not found to be suitable for cutting Steel
Question 86
The purpose of heat treatment is to
A. Relieve the stresses set up in the material after hot or cold working
B. Modify the structure of the material
C. Change grain size
D. Any one of these
View Answer
Answer: Option D
Explanation:
Heat treatment process effect on material structure and grains.Most carbon steels and carbon alloy steels can be heat treated for the purpose of improving mechanical properties such as tensile and yield strength. This is accomplished due to the heat treatment fundamentally altering the microstructure of the steel.
Question 87
The tensile strength of wrought iron is maximum
A. Along the lines of slag distribution
B. Perpendicular to lines of slag distribution
C. Uniform in all directions
D. None of the above
View Answer
Answer: Option A
Explanation:
The tensile strength of wrought iron is maximum. Along the lines of slag distribution
Question 88
Sulphur in steel
A. Acts as deoxidiser
B. Reduces the grain size
C. Decreases tensile strength and hardness
D. Lowers the toughness and transverse ductility
View Answer
Answer: Option D
Explanation:
sulfur is normally regarded as an impurity and has an adverse effect on impact properties when a steel is high in sulphur and low in manganese. Sulphur improves machinability but lowers transverse ductility and notched impact toughness and has little effects on the longitudinal mechanical properties
Question 89
Connecting rod is, usually, made from
A. Low carbon steel
B. High carbon steel
C. Medium carbon steel
D. High speed steel
View Answer
Answer: Option C
Explanation:
Connecting rod is, usually, made from Medium carbon steel
Question 90
Ball bearings are, usually, made from
A. Low carbon steel
B. High carbon steel
C. Medium carbon steel
D. Chrome steel
View Answer
Answer: Option D
Explanation:
Ball bearings are usually made from Chrome steel
Question 91
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
View Answer
Answer: Option B
Explanation:
Steel contains 50% or more iron
Question 92
The transistor is made of
A. Silver
B. Gold
C. Copper
D. Germanium
View Answer
Answer: Option D
Explanation:
The transistor is made of Germanium
Question 93
The portion of the blast furnace below its widest cross-section is called
A. Hearth
B. Stack
C. Bosh
D. Throat
View Answer
Answer: Option C
Explanation:
The portion of the blast furnace below its widest cross-section is called Bosh
Question 94
The silicon steel is widely used for
A. Connecting rods
B. Cutting tools
C. Generators and transformers in the form of laminated cores
D. Motor car crankshafts
View Answer
Answer: Option C
Explanation:
The silicon steel is widely used for Generators and transformers in the form of laminated cores
Question 95
Connecting rod is usually made of
A. Aluminium
B. Low carbon steel
C. Medium carbon steel
D. High carbon steel
View Answer
Answer: Option C
Explanation:
Generally rod are made of steel because of ability to absorb high impact at the expense of durability and also for lightness of steel.
Question 96
Blast furnace is used to produce
A. Pig iron
B. Cast iron
C. Wrought iron
D. Steel
View Answer
Answer: Option A
Explanation:
Blast furnace is used to produce Pig iron
Question 97
Compressive strength of grey cast iron in tonnes/cm is of the order of
A. 35
B. 57
C. 710
D. 1015
View Answer
Answer: Option B
Explanation:
Compressive strength of grey cast iron is 57 tonnes/cm
Question 98
Y-alloy contains
A. 3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
B. 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
C. 4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
D. 5 to 6% tin, 2 to 3% copper and rest aluminium
View Answer
Answer: Option B
Explanation:
Y-alloy contains 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
Question 99
Wrought iron
A. Is a ductile material
B. Can be easily forged or welded
C. Cannot stand sudden and excessive shocks
D. All of these
View Answer
Answer: Option D
Explanation:
Wrought iron is an iron alloy with very low carbon content with respect to cast iron. It is soft, ductile, magnetic, and has high elasticity and tensile strength. It can be heated and reheated and worked into various shapes.
Question 100
White cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. It is soft, tough and easily machined metal
D. Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
View Answer
Answer: Option B
Explanation:
White cast iron Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinableWhite cast iron is a cast iron without any alloy addition and with low C and Si content such that the structure is hard brittle iron carbide with no free graphite.A fast cooling rate prevents the precipitation of C as graphite.
Question 101
When the steel is normalized, its
A. Yield point increases
B. Ductility decreases
C. Ultimate tensile strength increases
D. All of these
View Answer
Answer: Option D
Explanation:
When the steel is normalized, its Yield point increases, Ductility decreases and Ultimate tensile strength increases
Question 102
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
View Answer
Answer: Option B
Explanation:
Amorphous material is one In which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid
Question 103
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
View Answer
Answer: Option D
Explanation:
The molecules in a solid move Back and forth like tiny pendulums
Question 104
Hardness of upper bainite (acicular structure) is about
A. RC 65
B. RC 48
C. RC 57
D. RC 80
View Answer
Answer: Option B
Explanation:
Hardness of upper bainite (acicular structure) is about RC 48
Question 105
A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as
A. Allotropic change
B. Recrystallization
C. Heat treatment
D. Precipitation
View Answer
Answer: Option A
Explanation:
A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as Allotropic change
Question 106
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
View Answer
Answer: Option C
Explanation:
A reversible change in the atomic structure of steel with corresponding change in the properties is known as Allotropic change
Question 107
Hardness of martensite is about
A. RC 65
B. RC 48
C. RC 57
D. RC 80
View Answer
Answer: Option A
Explanation:
Hardness of martensite is about RC 65
Question 108
A coarse grained steel
A. Is less tough and has a greater tendency to distort during heat treatment
B. Is more ductile and has a less tendency to distort during heat treatment
C. Is less tough and has a less tendency to distort during heat treatment
D. Is more ductile and has a greater tendency to distort during heat treatment
View Answer
Answer: Option A
Explanation:
A coarse grained steel is less tough and has a greater tendency to distort during heat treatment
Question 109
Which of the following pipes is least corrosion resistant?
A. Brass
B. Mild steel
C. Cast iron
D. Wrought iron
View Answer
Answer: Option D
Explanation:
Wrought iron is least corrosion resistant
Question 110
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
View Answer
Answer: Option A
Explanation:
Points of arrest for iron correspond to Stages at which allotropic forms change
Question 111
The charge is fed into the blast furnace through the
A. Stack
B. Throat
C. Bosh
D. Tyres
View Answer
Answer: Option B
Explanation:
The charge is fed into the blast furnace through the Throat
Question 112
The charge of the blast furnace consists of
A. Calcined ore (8 parts), coke (4 parts) and limestone (1 part)
B. Calcined ore (4 parts), coke (1 part) and limestone (8 parts)
C. Calcined ore (1 part), coke (8 parts) and limestone (4 parts)
D. Calcined ore, coke and limestone all in equal parts
View Answer
Answer: Option A
Explanation:
The charge of the blast furnace consists of Calcined ore (8 parts), coke (4 parts) and limestone (1 part)
Question 113
Pearlite consists of
A. 13% carbon and 87% ferrite
B. 13% cementite and 87% ferrite
C. 13% ferrite and 87% cementite
D. 6.67% carbon and 93.33% iron
View Answer
Answer: Option B
Explanation:
Pearlite consists of 13% cementite and 87% ferrite
Question 114
Balls for ball bearings are made of
A. Cast iron
B. Mild steel
C. Stainless steel
D. Carbon-chrome steel
View Answer
Answer: Option D
Explanation:
Balls for ball bearings are made of Carbon-chrome steel
Question 115
The property of a material essential for spring materials is
A. Stiffness
B. Ductility
C. Resilience
D. Plasticity
View Answer
Answer: Option C
Explanation:
resilience is the ability of a material to absorb energy when it is deformed elastically, and release that energy upon unloading.
Question 116
Grey cast iron has
A. Carbon in the form of free graphite
B. High tensile strength
C. Low compressive strength
D. All of these
View Answer
Answer: Option A
Explanation:
grey cast iron is a type of cast iron that has a graphitic microstructure
Question 117
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
View Answer
Answer: Option D
Explanation:
Gas turbine blade is made up of exotic materials superalloys to withstand in the difficult environment inside the gas turbine .As a consequence of operating the gas turbine at high temperature and high stresses, the turbine blades are subjected to certain deformation (creep)
Question 118
Iron-carbon alloys containing 1.7 to 4.3% carbon are known as
A. Eutectic cast irons
B. Hypoeutectic cast irons
C. Hypereutectic cast irons
D. None of these
View Answer
Answer: Option B
Explanation:
Iron-carbon alloys containing 1.7 to 4.3% carbon are known as Hypoeutectic cast irons
Question 119
Pipes for bicycle frames are made of
A. Cold rolled steel
B. Hot rolled steel
C. Forged steel
D. Cast steel
View Answer
Answer: Option A
Explanation:
Pipes for bicycle frames are made of Cold rolled steel
Question 120
Which of the following metal is used for nuclear energy?
A. Uranium
B. Thorium
C. Niobium
D. All of these
View Answer
Answer: Option D
Explanation:
Uranium, Thorium and Niobium metal are used for nuclear energy
Question 121
Aluminium bronze contains aluminium and copper in the ratio of
A. 50 : 50
B. 40 : 60
C. 60 : 40
D. 10 : 90
View Answer
Answer: Option D
Explanation:
Aluminium bronze contains aluminium and copper in the ratio of 10 : 90
Question 122
Phosphor bronze contains
A. 0.5% of phosphorous
B. 1% phosphorous
C. 2.5% phosphorous
D. None of the above
View Answer
Answer: Option D
Explanation:
phosphor bronze is an alloy of copper with 0.5–11% of tin and 0.01–0.35% phosphorus
Question 123
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
View Answer
Answer: Option B
Explanation:
A material is known as allotropic or polymorphic if it Exists in several crystal forms at different temperatures
Question 124
Sulphur in cast iron
A. Makes the iron soft and easily machinable
B. Increases hardness and brittleness
C. Make the iron white and hard
D. Aids fusibility and fluidity
View Answer
Answer: Option B
Explanation:
Sulphur in cast iron Increases hardness and brittleness
Question 125
An example of amorphous material is
A. Zinc
B. Lead
C. Silver
D. Glass
View Answer
Answer: Option D
Explanation:
Glass is an example of amorphous material
Question 126
Steel made from phosphate iron is
A. Brittle
B. Hard
C. Ductile
D. Tough
View Answer
Answer: Option A
Explanation:
Steel made from phosphate iron is Brittle
Question 127
The alloying element which reduces the formation of iron sulphide in steel is
A. Chromium
B. Nickel
C. Vanadium
D. Manganese
View Answer
Answer: Option D
Explanation:
Manganese reduces the formation of iron sulphide in steel
Question 128
In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.
A. Sulphur
B. Phosphorus
C. Manganese
D. Silicon
View Answer
Answer: Option B
Explanation:
In low carbon steels, Phosphorus raises the yield point and improves the resistance to atmospheric corrosion.
Question 129
Permalloy is a
A. Kind of stainless steel
B. None ferrous alloy
C. Polymer
D. Nickel and iron alloy having high permeability
View Answer
Answer: Option D
Explanation:
Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content
Question 130
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
View Answer
Answer: Option A
Explanation:
Austempering is heat treatment that is applied to ferrous metals, most notably steel and ductile iron.In steel it produces a bainite microstructure whereas in cast irons it produces a structure of acicular ferrite and high carbon, stabilized austenite known as ausferrite
Question 131
Which is false statement about tempering? Tempering is done to
A. Improve machinability
B. Improve ductility
C. Improve toughness
D. Release stresses
View Answer
Answer: Option A
Explanation:
Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys
Question 132
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
View Answer
Answer: Option A
Explanation:
Super conduction by metals is observed in the temperature range of Below 10°K
Question 133
Ferromagnetic alpha iron exists in temperature range of
A. Below 723°C
B. 770 to 910°C
C. 910 to 1440°C
D. 1400 to 1539°C
View Answer
Answer: Option A
Explanation:
alpha iron is a component of steel and cast iron, conferring Ferromagnetism.the maximum solubility is at 727 °C
Question 134
Gamma iron exits at following temperature
A. Room temperature
B. Near melting point
C. Between 1400°C and 1539°C
D. Between 910°C and 1400°C
View Answer
Answer: Option D
Explanation:
Gamma iron is an allotropic form of iron existing between the temperature 910°C and 1400°C and having a face-centered cubic lattice
Question 135
Dow metal contains
A. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B. 92.5% aluminium and, 4% copper, 2% nickel and 1.5% Mg
C. 90% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper
View Answer
Answer: Option D
Explanation:
Dow metal contains 90% magnesium and 9% aluminium with some copper
Question 136
Which of the following is an amorphous material?
A. Mica
B. Silver
C. Lead
D. Glass
View Answer
Answer: Option D
Explanation:
amorphous or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal
Question 137
Which of the following is used for bearing liner?
A. Gun metal
B. Bronze
C. Bell metal
D. Babbitt metal
View Answer
Answer: Option D
Explanation:
It is a soft, white non-ferrous alloy which is used to provide a bearing surface. Bearings are used in engines to support moving mechanical parts and protect them from frictional degradation.Babbitt metal also has properties that help it reduce friction which makes it a good material for use in a plain bearing
Question 138
White cast iron contains carbon in the form of
A. Free carbon
B. Graphite
C. Cementite
D. White carbon
View Answer
Answer: Option C
Explanation:
White cast iron contains carbon in the form of Cementite
Question 139
Weld decay is the phenomenon found with
A. Cast iron
B. Mild steel
C. Nonferrous materials
D. Stainless steel
View Answer
Answer: Option D
Explanation:
Weld decay is a form of intergranular corrosion, usually of stainless steels or certain nickel-base alloys, that occurs as the result of sensitization in the heat-affected zone during the welding operation
Question 140
Which of the following property is desirable for materials used in tools and machines?
A. Elasticity
B. Plasticity
C. Ductility
D. Malleability
View Answer
Answer: Option A
Explanation:
elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed
Question 141
Cupola produces following material
A. Cast iron
B. Pig iron
C. Wrought iron
D. Malleable iron
View Answer
Answer: Option A
Explanation:
Cupola is used to melt pig iron to make iron castings in foundry. Charge consists of pig iron, scrap and limestone and coke
Question 142
Mild steel belongs to the following category
A. Low carbon steel
B. Medium carbon steel
C. High carbon steel
D. Alloy steel
View Answer
Answer: Option A
Explanation:
Mild steel belongs to the following category of Low carbon steel
Question 143
The usual composition of a soldering alloy is
A. Tin, lead and small percentage of antimony
B. Tin and lead
C. Tin, lead and silver
D. Tin and copper
View Answer
Answer: Option A
Explanation:
Soldering alloy contains Tin, lead and small percentage of antimony
Question 144
The metal suitable for bearings subjected to light loads, is
A. Silicon bronze
B. White metal
C. Monel metal
D. Phosphor bronze
View Answer
Answer: Option D
Explanation:
The metal suitable for bearings subjected to light loads, is Phosphor bronze
Question 145
The metal suitable for bearings subjected to heavy loads, is
A. Silicon bronze
B. White metal
C. Monel metal
D. Phosphor bronze
View Answer
Answer: Option B
Explanation:
The metal suitable for bearings subjected to heavy loads, is White metal
Question 146
Nickel when added to copper improves
A. Machinability
B. Hardness
C. Hardness and strength
D. Strength and ductility
View Answer
Answer: Option B
Explanation:
The addition of nickel to copper improves strength and corrosion resistance while allowing the alloy to remain ductile.
Question 147
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
View Answer
Answer: Option D
Explanation:
For the allotropic forms of iron, the points of arrest are The points of discontinuity
Question 148
Hematite iron ore contains iron about
A. 30%
B. 45%
C. 55%
D. 70%
View Answer
Answer: Option D
Explanation:
The principal iron ores are hematite (Fe2O3) . Hematite is an iron oxide mineral.Hematite contains iron about 70%
Question 149
In grey cast iron, carbon is present in the form of
A. Cementite
B. Free carbon
C. Flakes
D. Spheroids
View Answer
Answer: Option C
Explanation:
In grey cast iron, carbon is present in the form of Flakes
Question 150
In malleable iron, carbon is present in the form of
A. Cementite
B. Free carbon
C. Flakes
D. Nodular aggregates of graphite
View Answer
Answer: Option D
Explanation:
In malleable iron, carbon is present in the form of Nodular aggregates of graphite
Question 151
Nodular iron has
A. High machinability
B. Low melting point
C. High tensile strength
D. All of the above
View Answer
Answer: Option D
Explanation:
nodular iron, obtains its special properties through the addition of magnesium into the alloy. The presence of magnesium causes the graphite to form in a spheroid shape as opposed to the flakes of gray iron.Composition control is very important in the manufacturing process. Small amounts of impurities such as sulfur and oxygen react with the magnesium, affecting the shape of the graphite molecules.Different grades of ductile iron are formed by manipulating the microcrystalline structure around the graphite spheroid. This is achieved through the casting process, or through heat treatment, as a downstream processing step.
Question 152
Nickel 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 anti-corrosion properties
View Answer
Answer: Option D
Explanation:
Nickel in steel Gives ductility, toughness, tensile strength and anti-corrosion properties
Question 153
Dislocations in materials refer to the following type of defect
A. Point defect
B. Line defect
C. Plane defect
D. Volumetric defect
View Answer
Answer: Option B
Explanation:
Dislocations in materials refer to Line defect Line defects are lines along which whole rows of atoms in a solid are arranged anomalously. The resulting irregularity in spacing is most severe along a line called the line of dislocation.Line defects can weaken or strengthen solids.
Question 154
The main alloying elements high speed steel in order of increasing proportion are
A. Vanadium, chromium, tungsten
B. Tungsten, titanium, vanadium
C. Chromium, titanium, vanadium
D. Tungsten, chromium, titanium
View Answer
Answer: Option A
Explanation:
The main alloying elements high speed steel in order of increasing proportion are Vanadium, chromium, tungsten
Question 155
Induction hardening is basically a
A. Carburising process
B. Surface hardening process
C. Core hardening process
D. None of these
View Answer
Answer: Option B
Explanation:
Induction hardening is a type of surface hardening in which a metal part is induction-heated and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part
Question 156
Which of the following is not the correct method of increasing fatigue limit?
A. Shot peening
B. Nitriding of surface
C. Cold working
D. Surface decarburisation
View Answer
Answer: Option D
Explanation:
Decarburization is a surface degradation phenomenon in the forging and heat treating of steels.
Question 157
The property of a material which enables it to retain the deformation permanently, is called
A. Brittleness
B. Ductility
C. Malleability
D. Plasticity
View Answer
Answer: Option D
Explanation:
plasticity describes the deformation of a material undergoing non-reversible changes of shape in response to applied forces.
Question 158
The brown smoke during the operation of a Bessemer converter indicates that the
A. Air is burning out silicon and manganese
B. Silicon and manganese has burnt and carbon has started oxidizing
C. The converter must be titled to remove the contents of the converter
D. The brown smoke does not occur during the operation of a Bessemer converter
View Answer
Answer: Option A
Explanation:
The brown smoke during the operation of a Bessemer converter indicates that the Air is burning out silicon and manganese
Question 159
Iron ore is usually found in the form of
A. Oxides
B. Carbonates
C. Sulphides
D. All of these
View Answer
Answer: Option D
Explanation:
Iron ore is usually found in the form of Oxides, Carbonates and Sulphides
Question 160
German silver contains
A. 1% silver
B. 2% silver
C. 5% silver
D. No silver
View Answer
Answer: Option D
Explanation:
The usual formulation of german silver is 60% copper, 20% nickel and 20% zinc. German silver is named due to its silvery appearance, but it contains no elemental silver unless plated.
Question 161
Drop forging dies contain carbon of the order of
A. 0.1 to 0.2%
B. 0.25 to 0.5%
C. 0.6 to 0.7%
D. 0.7 to 0.9%
View Answer
Answer: Option C
Explanation:
Drop forging dies contain carbon of the order of 0.6 to 0.7%
Question 162
Combined carbon in iron makes the metal
A. Soft and gives coarse grained crystalline structure
B. Soft and gives a fine grained crystalline structure
C. Hard and gives a coarse grained crystalline structure
D. Hard and gives a fine grained crystalline structure
View Answer
Answer: Option D
Explanation:
Combined carbon in iron makes the metal Hard and gives a fine grained crystalline structure
Question 163
In mottled cast iron, carbon is available in
A. Free form
B. Combined form
C. Nodular form
D. Partly in free and partly in combined state
View Answer
Answer: Option D
Explanation:
In mottled cast iron, carbon is available in Partly in free and partly in combined state
Question 164
The presence of hydrogen in steel causes
A. Reduced neutron absorption cross-section
B. Improved Weldability
C. Embrittlement
D. Corrosion resistance
View Answer
Answer: Option C
Explanation:
. The result of hydrogen embrittlement is that components crack and fracture at stresses less than the yield strength of the metal.
Question 165
Maximum percentage of carbon in austenite is
A. 0.03%
B. 0.26%
C. 0.80%
D. 1.70%
View Answer
Answer: Option D
Explanation:
Austenite is a face centred cubic structure (fcc). It is stable at temperatures above 723C depending upon carbon content. It can dissolve upto 2% carbon.
Question 166
The hardness and tensile strength in austenitic stainless steel can be increased by
A. Hardening and cold working
B. Normalizing
C. Martempering
D. Full annealing
View Answer
Answer: Option A
Explanation:
The hardness and tensile strength in austenitic stainless steel can be increased by Hardening and cold working
Question 167
Machining properties of steel are improved by adding
A. Sulphur, lead, phosphorous
B. Silicon, aluminium, titanium
C. Vanadium, aluminium
D. Chromium, nickel
View Answer
Answer: Option A
Explanation:
Machining properties of steel are improved by adding Sulphur, lead, phosphorous
Question 168
The machinability of steel is improved by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
View Answer
Answer: Option D
Explanation:
The machinability of steel is improved by adding Sulphur, lead and phosphorus
Question 169
Nodular cast iron is produced by adding ________ to the molten cast iron.
A. Nickel
B. Chromium
C. Copper
D. Magnesium
View Answer
Answer: Option D
Explanation:
Nodular cast iron is produced by adding magnesium to the molten cast iron.
Question 170
Addition of manganese to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
View Answer
Answer: Option B
Explanation:
When manganese is added to aluminum, its strength is increased slightly through solution strengthening and its strain hardening is also improved
Question 171
Addition of copper to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
View Answer
Answer: Option C
Explanation:
The copper provides substantial increases in strength and facilitates precipitation hardening.The introduction of copper to aluminum can also reduce ductility and corrosion resistance
Question 172
Addition of lead and bismuth to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
View Answer
Answer: Option D
Explanation:
Addition of lead and bismuth to aluminium results in Improving machinability
Question 173
Addition of silicon to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
View Answer
Answer: Option A
Explanation:
addition of silicon is for ease of casting.Silicon is good in metallic alloys used for casting. This is because it increases the fluidity of the melt, reduces the melting temperature, decreases the contraction associated with solidification and is very cheap as a raw material
Question 174
The hardness of steel primarily depends on
A. Percentage of carbon
B. Percentage of alloying elements
C. Heat treatment employed
D. Shape of carbides and their distribution in iron
View Answer
Answer: Option D
Explanation:
carbon is the most important commercial steel alloy.Increasing carbon content increases hardness and strength and improves hardenability. But carbon also increases brittleness and reduces weldability because of its tendency to form martensite.
Question 175
Beryllium bronze contains
A. 60% copper and 40% beryllium
B. 80% copper and 20% beryllium
C. 97.75% copper and 2.25% beryllium
D. 99% copper and 1% beryllium
View Answer
Answer: Option C
Explanation:
Beryllium bronze contains 97.75% copper and 2.25% beryllium
Question 176
Aluminium bronze contains
A. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B. 92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
C. 10% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper
View Answer
Answer: Option C
Explanation:
Aluminium bronze contains 10% aluminium and 90% copper
Question 177
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
A. Increase
B. Decrease
C. Remain same
D. First increase and then decrease
View Answer
Answer: Option A
Explanation:
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will Increase
Question 178
The percentage of carbon in grey iron castings usually varies between
A. 0.5 to 1%
B. 1.20%
C. 2.5 to 4.5%
D. 5 to 7%
View Answer
Answer: Option C
Explanation:
Most cast irons have a chemical composition of 2.5–4.0% carbon, 1–3% silicon, and the remainder iron. Grey cast iron has less tensile strength and shock resistance than steel, but its compressive strength is comparable to low- and medium-carbon steel.
Question 179
The material widely used for making pendulums of clocks is
A. Stainless steel
B. High speed steel
C. Heat resisting steel
D. Nickel steel
View Answer
Answer: Option D
Explanation:
The material widely used for making pendulums of clocks is Nickel steel nickel enhances important properties of stainless steel such as formability, weldability and ductility, while increasing corrosion resistance in certain applications
Question 180
Taps dies and drills contain carbon
A. Below 0.5%
B. Below 1%
C. Above 1%
D. Above 2.2%
View Answer
Answer: Option C
Explanation:
Taps dies and drills contain carbon Above 1%
Question 181
Solder is an alloy consisting of
A. Tin, antimony, copper
B. Tin and copper
C. Tin and lead
D. Lead and zinc
View Answer
Answer: Option B
Explanation:
Solder is an alloy contains Tin and copper
Question 182
Malleable cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. It is soft, tough, and easily machined metal
D. Is produced by small additions of magnesium (or cerium) in the ladle. Graphite is in the nodular or spheroidal form and is well dispersed throughout the material
View Answer
Answer: Option C
Explanation:
Malleable iron is cast as white iron, the structure being a metastable carbide in a pearlitic matrix. Through an annealing heat treatment, the brittle structure as first cast is transformed into the malleable form.
Question 183
Bell metal contains
A. 70% copper and 30% zinc
B. 90% copper and 10% tin
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 75% copper and rest tin
View Answer
Answer: Option D
Explanation:
Bell metal contains 70 - 75% copper and rest tin
Question 184
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
View Answer
Answer: Option D
Explanation:
Normalizing is normally done to achieve any one of the following purposes. To modify and/or refine the grain structure and to eliminate coarse grained structures obtained in previous working operations such as rolling and forging.
Question 185
Chilled cast iron has
A. No graphite
B. A very high percentage of graphite
C. A low percentage of graphite
D. Graphite as its basic constituent of composition
View Answer
Answer: Option A
Explanation:
Chilled cast iron. Iron-carbon alloy with low graphitization factor so that chill occurs forming a graphite-free structure.The carbon is present bonded in the form of iron carbide, which is why the break surface of the material appears whitish instead of gray
Question 186
The aluminium alloy, mainly used, for anodized utensil manufacture, is
A. Duralumin
B. Y-alloy
C. Magnalium
D. Hindalium
View Answer
Answer: Option D
Explanation:
cooking vessels made of aluminium or hindalium for cooking food. Even if a steel spoon is brushed with force against aluminium vessels, minute particles of aluminium will appear as residue.Hindalium is Alloy of aluminium magnesium, manganese, chromium and silicon
Question 187
The machinability of steel is increased by
A. Silicon and sulphur
B. Phosphorous, lead and sulphur
C. Sulphur, graphite and aluminium
D. Phosphorous and aluminium
View Answer
Answer: Option B
Explanation:
Phosphorous, lead and sulphur improves machinability and resistance to corrosion and it intensifies the effects of other alloying elements
Question 188
White cast iron has
A. Carbon in the form of carbide
B. Low tensile strength
C. High compressive strength
D. All of these
View Answer
Answer: Option D
Explanation:
When white iron is sheared, the fractured face appears white due to the absence of graphite. The cementite microcrystalline structure is hard and brittle with a high compressive strength and good wear resistance. In certain specialized applications, it is desirable to have white iron on the surface of the product.This can be achieved by using a good conductor of heat to make part of the mold. This will draw heat out of the molten metal quickly from that specific area, while the rest of the casting cools at a slower rate.
Question 189
When a steel containing __________ 0.8% carbon is cooled slowly below the lower critical point, it consists of ferrite and pearlite.
A. Equal to
B. Less than
C. More than
D. None of these
View Answer
Answer: Option B
Explanation:
When a steel containing less than 0.8% carbon is cooled slowly below the lower critical point, it consists of ferrite and pearlite.
Question 190
The ratio of the volume occupied by the atoms to the total volume of the unit cell is called
A. Coordination number
B. Atomic packing factor
C. Space lattice
D. None of these
View Answer
Answer: Option B
Explanation:
The ratio of the volume occupied by the atoms to the total volume of the unit cell is called Atomic packing factor
Question 191
Induction hardening is the process of
A. Hardening surface of work-piece to obtain hard and wear resistant surface
B. Heating and cooling rapidly
C. Increasing hardness throughout
D. Inducing hardness by continuous process
View Answer
Answer: Option A
Explanation:
Induction hardening is a process used for the surface hardening of steel and other alloy components. The parts to be heat treated are placed inside a water cooled copper coil and then heated above their transformation temperature by applying an alternating current to the coil.
Question 192
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
View Answer
Answer: Option C
Explanation:
A process in which an iron-base alloy is heated in contact with a cyanide salt so that the surface absorbs carbon and nitrogen.Cyaniding is followed by quenching and tempering to produce a case with a desired combination of hardness and toughness.
Question 193
Stress relaxation is the phenomenon
A. In which parts are not loaded
B. In which stress remains constant on increasing load
C. In which deformation tends to loosen the joint and produces a stress reduced
D. Stress reduces on increasing load
View Answer
Answer: Option C
Explanation:
Stress relaxation is a gradual reduction in stress with time at constant strain. Stress relaxation occurs in polymers when they are held in a strained state for long periods of time. These alloys have very good resistance to stress relaxation and are therefore used as spring materials.
Question 194
In nodular iron, graphite is in the form of
A. Cementite
B. Free carbon
C. Flakes
D. Spheroids
View Answer
Answer: Option D
Explanation:
spheroidal graphite iron, in which graphite appears as spherical nodules and ductility is greatly increased.
Question 195
When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces
A. White cast iron
B. Nodular cast iron
C. Malleable cast iron
D. Alloy cast iron
View Answer
Answer: Option D
Explanation:
When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces Alloy cast iron alloy cast iron - cast iron containing alloying elements (usually nickel or chromium or copper or molybdenum) to increase the strength or facilitate heat treatment. alloy iron. cast iron - an alloy of iron containing so much carbon that it is brittle and so cannot be wrought but must be shaped by casting.
Question 196
Iron is
A. Paramagnetic
B. Ferromagnetic
C. Ferroelectric
D. Dielectric
View Answer
Answer: Option B
Explanation:
Ferromagnetism refers to materials (such as iron and nickel) that can retain their magnetic properties when the magnetic field is removed.
Question 197
Corundum contains more than 95%
A. Steel
B. Al2O3
C. SiO2
D. MgO
View Answer
Answer: Option B
Explanation:
Corundum is a crystalline form of aluminium oxide (Al 2O 3) typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral
Question 198
For a steel containing 0.8% carbon
A. There is no critical point
B. There is only one critical point
C. There are two critical points
D. There can be any number of critical points
View Answer
Answer: Option B
Explanation:
When steels with exactly 0.8% carbon (known as a eutectoid steel), are cooled, the austenitic phase (FCC) of the mixture attempts to revert to the ferrite phase (BCC)There is only one critical point in eutectoid steel which contains 0.8% carbon
Question 199
Age hardening is related to
A. Duralumin
B. Brass
C. Copper
D. Silver
View Answer
Answer: Option A
Explanation:
age hardening is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminium, magnesium, nickel, titanium, and some steels and stainless steels.Age hardening is related to Duralumin
Question 200
Inconel contains
A. 65% nickel, 15% chromium and 20% iron
B. 68% nickel, 29% copper and 3% other constituents
C. 80% nickel and 20% chromium
D. 80% nickel, 14% chromium and 6% iron
View Answer
Answer: Option D
Explanation:
Inconel contains 80% nickel, 14% chromium and 6% iron
Question 201
The presence of sulphur in pig iron makes
A. It easily machinable
B. It brittle
C. It hard
D. The casting unsound
View Answer
Answer: Option D
Explanation:
As sulfur in Pig Iron make the cast iron manufacturing unsound and not pure because sulfur works as a impurities in Pig iron. ... Iron sulphide being very brittle, whole alloy becomes brittle. Presence of sulfur tends to make iron hard and produces unsound castings
Question 202
There are fourteen atoms in a unit cell of
A. Body centered cubic space lattice
B. Face centered cubic space lattice
C. Close packed hexagonal space lattice
D. None of these
View Answer
Answer: Option B
Explanation:
There are fourteen atoms in a unit cell of Face centered cubic space lattice
Question 203
Which is false statement about properties of aluminium?
A. Modulus of elasticity is fairly low
B. Wear resistance is very good
C. Fatigue strength is not high
D. Creep strength limits its use to fairly low temperatures
View Answer
Answer: Option B
Explanation:
There are some properties of aluminium is listed below:Low densitySimple to processSmooth surfaceLower dimensional tolerancesNot magnetisableCan be decoratively anodised very well (dependent on the alloy)Good machinability (dependent on the strength and alloying elements)
Question 204
Cartridge brass can be
A. Cold rolled into sheets
B. Drawn into wires
C. Formed into tube
D. Any one of these
View Answer
Answer: Option D
Explanation:
sometimes referred to as yellow brass, has a nominal composition of 70% copper and 30% zinc.Cartridge brass can be Cold rolled into sheets and Drawn into wires and Formed into tube
Question 205
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
View Answer
Answer: Option A
Explanation:
Isotropic materials are those which have the same Elastic properties in all directions
Question 206
The material in which the atoms are arranged chaotically, is called
A. Amorphous material
B. Mesomorphous material
C. Crystalline material
D. None of these
View Answer
Answer: Option A
Explanation:
The amorphous material is a noncrystalline solid, and the glass is amorphous material produced through melt quenching.
Question 207
Tungsten when added to steel __________ the critical temperature.
A. Does not effect
B. Lowers
C. Raises
D. None of these
View Answer
Answer: Option C
Explanation:
Tungsten when added to steel to raises the critical temperature.
Question 208
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 centered cubic iron and face centered cubic iron
D. Alpha iron, gamma from and delta iron
View Answer
Answer: Option D
Explanation:
Alpha iron, gamma from and delta iron are the allotropic form of iron.
Question 209
The addition of which of the following improves machining of copper?
A. Sulphur
B. Vanadium
C. Tin
D. Zinc
View Answer
Answer: Option A
Explanation:
The addition sulphur improves machining of copper
Question 210
Vanadium in high speed steels
A. Promotes decarburisation
B. Provides high hot hardness
C. Forms very hard carbides and thus increases wear resistance
D. Promotes retention of austenite
View Answer
Answer: Option C
Explanation:
The effects of Vanadium refines grain size, increases hardenability, fracture toughness, and resistance to shock loading. Softening at high temperatures, fatigue stress and wear resistance are improved. At greater than 0.05%, there may be a tendency for the steel to become embrittled during thermal stress relief treatments.Vanadium is used in nitriding, heat resisting, tool and spring steels together with other alloying elements.
Question 211
Basic solution is one which has pH value
A. Greater than 7
B. Equal to 7
C. Less than 7
D. pH value has nothing to do with basic solution
View Answer
Answer: Option A
Explanation:
Basic solution is one which has pH value Greater than 7
Question 212
Neutral solution is one which has pH value
A. Greater than 7
B. Less than 7
C. Equal to 7
D. pH value has nothing to do with neutral solution
View Answer
Answer: Option C
Explanation:
Neutral solution is one which has pH value Equal to 7
Question 213
Acidic solution is one which has pH value
A. Greater than 7
B. Less than 7
C. Equal to 7
D. pH value has nothing to do with neutral solution
View Answer
Answer: Option B
Explanation:
Acidic solution is one which has pH value Less than 7
Question 214
The toughness of a material __________ when it is heated.
A. Remain same
B. Decreases
C. Increases
D. None of these
View Answer
Answer: Option B
Explanation:
The toughness of a material decrease when it is heated.
Question 215
Which of the following metal is used in making electrical resistance wire for electric furnaces and heating elements?
A. Babbitt metal
B. Monel metal
C. Nichrome
D. Phosphor bronze
View Answer
Answer: Option C
Explanation:
Chromium is a powerful alloying element in steel. Cr presents in certain structural steels in small amounts. It is primarily used to increase hardenability of steel and increase the corrosion resistance as well as the yield strength of the steel material. For that reason often occurs in combination with nickel and copper. Stainless steels may contain in excess of 12% chromium.
Question 216
In the lower part of the blast furnace (zone of fusion), the temperature is
A. 400° to 700°C
B. 800°C to 1000°C
C. 1200°C to 1300°C
D. 1500°C to 1700°C
View Answer
Answer: Option C
Explanation:
In the lower part of the blast furnace (zone of fusion), the temperature is 1200°C to 1300°C
Question 217
The heat treatment process used for softening hardened steel is
A. Carburising
B. Normalizing
C. Annealing
D. Tempering
View Answer
Answer: Option D
Explanation:
Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys
Question 218
Which of the following impurity in cast iron makes it hard and brittle?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
View Answer
Answer: Option B
Explanation:
Sulfur is normally regarded as an impurity and has an adverse effect on impact properties when a steel is high in sulphur and low in manganese. Sulphur improves machinability but lowers transverse ductility and notched impact toughness and has little effects on the longitudinal mechanical properties.
Question 219
An engineer's hammer is made of
A. Cast iron
B. Forged steel
C. Mild steel
D. High carbon steel
View Answer
Answer: Option D
Explanation:
An engineer's hammer is made of High carbon steel
Question 220
The alloying element which can replace tungsten in high speed steels is
A. Nickel
B. Vanadium
C. Cobalt
D. Molybdenum
View Answer
Answer: Option D
Explanation:
Molybdenum has effects similar to manganese and vanadium, and is often used in combination with one or the other. This element is a strong carbide former and is usually present in alloy steels in amounts less than 1%. It increases hardenability and elevated temperature strength and also improves corrosion resistance as well as increased creep strength. It is added to stainless steels to increase their resistance to corrosion and is also used in high speed tool steels.
Question 221
Grey cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. I is soft, tough and easily machined metal
D. Is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroidal form and is well dispersed throughout the material
View Answer
Answer: Option A
Explanation:
Grey cast iron Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
Question 222
Which of the following element results in presence of free graphite in C.I.?
A. Carbon
B. Sulphur
C. Silicon
D. Manganese
View Answer
Answer: Option C
Explanation:
Silicon element results in presence of free graphite in C.I.
Question 223
The percentage carbon content in wrought iron is about
A. 0.02
B. 0.1
C. 2
D. 0.4
View Answer
Answer: Option A
Explanation:
Wrought iron is a form of commercial iron containing less than 0.10% of carbon, less than 0.25% of impurities total of sulfur, phosphorus, silicon and manganese, and less than 2% slag by weight. Wrought iron is redshort or hot short if it contains sulfur in excess quantity.
Question 224
Age-hardening is related with
A. Stainless steel
B. Gun metal
C. German silver
D. Duralumin
View Answer
Answer: Option D
Explanation:
age hardening is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminium, magnesium, nickel, titanium, and some steels and stainless steels.Age-hardening is related with duralumin
Question 225
Tensile strength of steel can be safely increased by
A. Adding carbon up to 2.8%
B. Adding carbon up to 6.3%
C. Adding carbon up to 0.83%
D. Adding small quantities of copper
View Answer
Answer: Option C
Explanation:
Tensile strength of steel can be safely increased by Adding carbon up to 0.83%
Question 226
Basic constituents of Monel metal are
A. Nickel, copper
B. Nickel, molybdenum
C. Zinc, tin, lead
D. Nickel, lead and tin
View Answer
Answer: Option A
Explanation:
Monel is a group of nickel alloys, primarily composed of nickel and copper, with small amounts of iron, manganese, carbon, and silicon.
Question 227
Steel with __________ carbon is known as hypo-eutectoid steel.
A. 0.80%
B. Below 0.8%
C. Above 0.8%
D. None of these
View Answer
Answer: Option B
Explanation:
Hypo-eutectoid steel has less than 0,8% of Carbon in its composition. It is composed by pearlite and α-ferrite
Question 228
In spheroidising process, the steel is
A. Heated below the lower critical temperature and then cooled slowly
B. Heated up to the lower critical temperature and then cooled in still air
C. Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
D. None of the above
View Answer
Answer: Option C
Explanation:
Spheroidizing of high carbon steel is a method of prolonged heating at a temperature below the eutectoid temperature. By heating at this temperature pearlite, which is the lowest energy arrangement of steel, gets converted to ferrite and cementite. .However, the process of spheroidizing does consume a lot of energy.
Question 229
Constantan an alloy used in thermocouples is an alloy of
A. Copper and tin
B. Copper and zinc
C. Copper and iron
D. Copper and nickel
View Answer
Answer: Option D
Explanation:
a copper–nickel alloy used in electrical work for its high resistance. It usually consists of 55% copper and 45% nickel
Question 230
The hardness of steel increases if it contains
A. Austenite
B. Martensite
C. Pearlite
D. Cementite
View Answer
Answer: Option B
Explanation:
Martensitic stainless steels contain from 12 to 18 percent chromium, imparting corrosion resistance, and from 0.12 to 1 percent carbon, permitting a great degree of hardening by heat treatment
Question 231
Gamma-iron occurs between the temperature ranges of
A. 400°C to 600°C
B. 600°C to 900°C
C. 900°C to 1400°C
D. 1400°C to 1530°C
View Answer
Answer: Option C
Explanation:
As the iron cools further to 1,394 °C its crystal structure changes to a face centered cubic (FCC) crystalline structure. In this form it is called gamma iron (γ-Fe) or Austenite. γ-iron can dissolve considerably more carbon (as much as 2.04% by mass at 1,146 °C). This γ form of carbon saturation is exhibited in stainless steel.
Question 232
Delta-iron occurs between the temperature ranges of
A. 400°C to 600°C
B. 600°C to 900°C
C. 900°C to 1400°C
D. 1400°C to 1530°C
View Answer
Answer: Option D
Explanation:
As molten iron cools down, it solidifies at 1,538 °C (2,800 °F) into its δ allotrope, which has a body-centered cubic (BCC) crystal structure.[5] δ-iron can dissolve as much as 0.08% of carbon by mass at 1,475 °C.
Question 233
The blade of a power saw is made of
A. Boron steel
B. High speed steel
C. Stainless steel
D. Malleable cast iron
View Answer
Answer: Option B
Explanation:
The blade of a power saw is made of High Speed Steel (HSS) to mainly cut copper, steel, aluminum and other materials except high-strength steel.
Question 234
German silver is an alloy of
A. Silver and some impurities
B. Refined silver
C. Nickel, Copper and zinc
D. Nickel and copper
View Answer
Answer: Option C
Explanation:
German Silver is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc
Question 235
Specify the sequence correctly
A. Grain growth, recrystallization, stress relief
B. Stress relief, grain growth, recrystallization
C. Stress relief, recrystallization, grain growth
D. Grain growth, stress relief, recrystallization
View Answer
Answer: Option C
Explanation:
the correct sequence is described are under as:Stress relief, recrystallization, grain growth
Question 236
Cementite consist of
A. 13% carbon and 87% ferrite
B. 13% cementite and 87% ferrite
C. 13% ferrite and 87% cementite
D. 6.67% carbon and 93.33% iron
View Answer
Answer: Option D
Explanation:
Cementite consist of 6.67% carbon and 93.33% iron It has an orthorhombic crystal structure.
Question 237
Preheating is essential in welding
A. Cast iron
B. High speed steel
C. All nonferrous materials
D. All of the above
View Answer
Answer: Option A
Explanation:
Preheating minimizes the temperature difference between the welding arc and the base material. .Slowing the cooling rate also allows hydrogen to escape the weld puddle as it hardens to help minimize cracking. preheating introduces the necessary heat into the weld area to ensure proper penetration.
Question 238
Which of the following material has nearly zero coefficient of expansion?
A. Stainless steel
B. High speed steel
C. Invar
D. Heat resisting steel
View Answer
Answer: Option C
Explanation:
Invar is a solid solution;, it is a single-phase alloy,it consisting of around 36% nickel and 64% iron.And uniquely it has nearly zero coefficient of expansion.
Question 239
When filing or machining cast iron makes our hands black, then it shows that ________ is present in cast iron.
A. Cementite
B. Free graphite
C. Both A and B
D. None of these
View Answer
Answer: Option B
Explanation:
When filing or machining cast iron makes our hands black, then it shows that free graphite is present in cast iron.
Question 240
When medium carbon steel is heated to coarsening temperature
A. There is no change in grain size
B. The average grain size is a minimum
C. The grain size increases very rapidly
D. The grain size first increases and then decreases very rapidly
View Answer
Answer: Option C
Explanation:
When medium carbon steel is heated to coarsening temperature the grain size increases very rapidly
Question 241
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
A. Sulphur
B. Phosphorus
C. Manganese
D. Silicon
View Answer
Answer: Option C
Explanation:
It is a mild deoxidant acting as a cleanser taking the sulphur and oxygen out of the melt into the slag.It increases the harden ability and tensile strength but decreases ductility.It combines with sulphur to form globular manganese sulphides, essential in free cutting steels for good machinability.
Question 242
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
View Answer
Answer: Option B
Explanation:
Recrystallization temperature is one At which new spherical crystals first begin to form from the old deformed one when a strained metal is heated
Question 243
If a refractory contains high content of silicon, it means refractory is
A. Acidic
B. Basic
C. Neutral
D. Brittle
View Answer
Answer: Option C
Explanation:
Refractory refers to the heat resistant material used in almost all processes involving high temperatures and/or corrosive environment. These are typically used to insulate and protect industrial furnaces and vessels due to their excellent resistance to heat, chemical attack and mechanical damage.
Question 244
The bond formed by transferring electrons from one atom to another is called
A. Ionic bond
B. Covalent bond
C. Metallic bond
D. None of these
View Answer
Answer: Option A
Explanation:
Ionic bonding is the complete transfer of valence electron(s) between atoms.It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion
Question 245
Which of the following constituents of steels is softest and least strong?
A. Austenite
B. Pearlite
C. Ferrite
D. Cementite
View Answer
Answer: Option C
Explanation:
Ferrites that are used in transformer or electromagnetic cores contain nickel, zinc, and/or manganese compounds.They have a low coercivity and are called soft ferrites.
Question 246
Macrostructure of a material is, generally, examined by
A. Naked eye
B. Optical microscope
C. Metallurgical microscope
D. X-ray techniques
View Answer
Answer: Option A
Explanation:
Macrostructure of a material is, generally, examined by Naked eye
Question 247
Structural steel contains following principal alloying elements
A. Nickel, chromium and manganese
B. Tungsten, molybdenum and phosphorous
C. Lead, tin, aluminium
D. Zinc, sulphur, and chromium
View Answer
Answer: Option A
Explanation:
Structural steel contains Nickel, chromium and manganese
Question 248
The most effective inhibitor of grain growth, when added in small quantities is
A. Carbon
B. Vanadium
C. Manganese
D. Cobalt
View Answer
Answer: Option B
Explanation:
Vanadium is traditionally known for its ability to retard grain growth at elevated temperatures and for its beneficial affinity for carbon and nitrogen.Vanadium promotes fine grain size, increases hardenability and improves wear resistance through the precipitation of its carbides and nitrides
Question 249
Monel metal is an alloy of
A. Nickel and copper
B. Nickel and chromium
C. Nickel, Chromium and iron
D. Copper and chromium
View Answer
Answer: Option A
Explanation:
Monel metal is an alloy of Nickel and copper
Question 250
Delta metal is an alloy of
A. Copper, zinc and iron
B. Iron, nickel and copper
C. Iron, lead and tin
D. Iron, aluminium and magnesium
View Answer
Answer: Option A
Explanation:
A brass alloy consisting of copper (55%), zinc (41-43%) and iron (1-3%), with the balance consisting of various other metals.The proportions used make the material harder and suitable for valves and bearings.
Question 251
The alloy, mainly used for corrosion resistance in stainless steels is
A. Silicon
B. Manganese
C. Carbon
D. Chromium
View Answer
Answer: Option D
Explanation:
Stainless steel is an alloy of Iron with a minimum of 10.5% Chromium.Chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'.This prevents any further corrosion of the surface. Increasing the amount of Chromium gives an increased resistance to corrosion.
Question 252
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
View Answer
Answer: Option D
Explanation:
The Bauschinger effect refers to a property of materials where the material's stress/strain characteristics change as a result of the microscopic stress distribution of the material. For example, an increase in tensile yield strength occurs at the expense of compressive yield strength
Question 253
In basic Bessemer process, the furnace is lined with
A. Silica bricks
B. A mixture of tar and burnt dolomite bricks
C. Both (A) and (B)
D. None of these
View Answer
Answer: Option B
Explanation:
The Bessemer process is an industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron.In basic Bessemer process, the furnace is lined with a mixture of tar and burnt dolomite bricks.
Question 254
Babbitt metal is a
A. Lead base alloy
B. Copper base alloy
C. Tin base alloy
D. Cadmium base alloy
View Answer
Answer: Option C
Explanation:
babbitt metal is a soft alloy of tin.babbitt metal contains 89.3% tin, 7.1% antimony and 3.6% copper.
Question 255
Which of the following iron exist between 910°C and 1403°C?
A. α-iron
B. β-iron
C. γ-iron
D. δ-iron
View Answer
Answer: Option C
Explanation:
Gamma iron is an allotropic form of iron existing between the temperature 910°C and 1400°C and having a face-centered cubic lattice. It is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element.
Question 256
In induction hardening ________ is high.
A. Current
B. Voltage
C. Frequency
D. Temperature
View Answer
Answer: Option C
Explanation:
Induction hardening is a type of surface hardening in which a metal part is induction-heated and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part.In induction hardening Frequency is high.
Question 257
According to Indian standard specifications, SG 400/15 means
A. Spheroidal graphite cast iron with B.H.N. 400 and minimum tensile strength 15 MPa
B. Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
C. Spheroidal graphite cast iron with minimum compressive strength 400 MPa and 15 percent reduction in area
D. None of the above
View Answer
Answer: Option B
Explanation:
S G Iron is a type of cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites. This imparts a measurable degree of ductility (easily manipulated) to the cast metalAccording to Indian standard specifications, SG 400/15 means Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
Question 258
An alloy of copper, tin and zinc is known as
A. Brass
B. Bronze
C. Gun metal
D. Muntz metal
View Answer
Answer: Option C
Explanation:
gun metal contains lead in addition to the zinc; it is typically composed of 86% copper, 9.5% tin, 2.5% lead, and 2% zinc.
Question 259
Paramagnetic alpha iron changes to gamma iron at
A. 770°C
B. 910°C
C. 1440°C
D. 1539°C
View Answer
Answer: Option B
Explanation:
Below 912 °C (1,674 °F) iron again adopts the BCC structure characteristic of α-iron, also called ferrite. The substance assumes a paramagnetic property. and it changes in to gamma iron
Question 260
Pure iron is the structure of
A. Ferrite
B. Pearlite
C. Austenite
D. Ferrite and cementite
View Answer
Answer: Option A
Explanation:
iron with a bcc structure is called ferrite. Another name for ferrite is alpha iron. ferrite is shown in figure
Question 261
The following types of materials are usually the most ductile
A. Face centered cubic lattice
B. Body centered cubic lattice
C. Hexagonal close packed lattice
D. All of the above
View Answer
Answer: Option A
Explanation:
A face-centered cubic crystal structure will exhibit more ductility (deform more readily under load before breaking) than a body-centered cubic structure.The bcc lattice, although cubic, is not closely packed and forms strong metals. Alpha-iron and tungsten have the bcc form.
Question 262
Nimonic contains __________ percentage of nickel as that of Inconel.
A. Same
B. Less
C. More
D. None of these
View Answer
Answer: Option A
Explanation:
Nimonic is nickel-based high-temperature low creep superalloys. Nimonic alloys typically consist of more than 50% nickel and 20% chromium with additives such as titanium and aluminium.
Question 263
Which one of the following metals would work-harden more quickly than the others?
A. Copper
B. Brass
C. Lead
D. Silver
View Answer
Answer: Option B
Explanation:
Unlike steel alloys, brass cannot be hardened by heating.Brass can only be strain or work-hardened.The hardening occurs when the material is worked mechanically, e.g. by cold working. The action of force does not harden brass
Question 264
Sulphur in pig iron tends to make it
A. Hard
B. Soft
C. Ductile
D. Tough
View Answer
Answer: Option A
Explanation:
Presence of sulfur tends to make iron hard and produces unsound castings. Wrought iron and steel produced from iron containing sulfur makes wrought iron and steel to be brittle when heated.
Question 265
In low carbon steels, presence of small quantities of sulphur improves
A. Weldability
B. Formability
C. Machinability
D. Hardenability
View Answer
Answer: Option C
Explanation:
Sulfur is normally regarded as an impurity and has an adverse effect on impact properties when a steel is high in sulphur and low in manganese.Sulphur improves machinability but lowers transverse ductility and notched impact toughness and has little effects on the longitudinal mechanical properties
Question 266
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
View Answer
Answer: Option B
Explanation:
The ultimate tensile strength of low carbon steel by working at a high strain rate will Increase
Question 267
Normalising of steel is done to
A. Refine the grain structure
B. Remove strains caused by cold working
C. Remove dislocations caused in the internal structure due to hot working
D. All of the above
View Answer
Answer: Option D
Explanation:
Normalising of steel is done to Refine the grain structure and Remove strains caused by cold working and Remove dislocations caused in the internal structure due to hot working
Question 268
Hardness of steel depends on
A. Amount of carbon it contains
B. The shape and distribution of the carbides in iron
C. Method of fabrication
D. Contents of alloying elements
View Answer
Answer: Option A
Explanation:
Depending on the temperature and composition of the steel, it can be hardened or softened. To make steel harder, it must be heated to very high temperatures.The final result of exactly how hard the steel becomes depends on the amount of carbon present in the metal.
Question 269
The coordination number of a face centered cubic space lattice is
A. Six
B. Twelve
C. Eighteen
D. Twenty
View Answer
Answer: Option B
Explanation:
The face-centered cubic (fcc) has a coordination number of 12 and contains 4 atoms per unit cell. The body-centered cubic (bcc) has a coordination number of 8 and contains 2 atoms per unit cell. The simple cubic has a coordination number of 6 and contains 1 atom per unit cell
Question 270
The composition of silver solder is
A. Silver, copper, zinc
B. Silver, tin, nickel
C. Silver, lead, zinc
D. Silver, copper, aluminium
View Answer
Answer: Option A
Explanation:
silver solder is composition of Silver, copper, zinc
Question 271
Materials after cold working are subjected to following process to relieve stresses
A. Hot working
B. Tempering
C. Normalizing
D. Annealing
View Answer
Answer: Option D
Explanation:
A heat treatment used to eliminate part or all of the effects of cold working. Cold working - Deformation of a metal below the recrystallization temperature. During cold working, the number of dislocations increases, causing the metal to be strengthened as its shape is changed.
Question 272
Argentite is the principal ore or raw material for
A. Aluminium
B. Tin
C. Zinc
D. Silver
View Answer
Answer: Option D
Explanation:
Silver is extracted from the ore-argentite
Question 273
Melting point of iron is
A. 1539°C
B. 1601°C
C. 1489°C
D. 1712°C
View Answer
Answer: Option A
Explanation:
Melting point of iron is 1539°C
Question 274
The metallic structure of mild steel is
A. Body centered cubic
B. Face centered cubic
C. Hexagonal close packed
D. Cubic structure
View Answer
Answer: Option A
Explanation:
The metallic structure of mild steel is Body centered cubicBCC structure is shown in figure
Question 275
The basic constituents of Hastelloy are
A. Aluminium, copper etc.
B. Nickel, molybdenum etc.
C. Nickel, Copper, etc.
D. All of the above
View Answer
Answer: Option B
Explanation:
The basic constituents of Hastelloy are 22% chromium, 13% molybdenum, and less than 3% iron.
Question 276
The crystal structure of gamma iron is
A. Body centered cubic
B. Face centered cubic
C. Hexagonal close packed
D. Cubic structure
View Answer
Answer: Option B
Explanation:
The crystal structure of gamma iron is Face centered cubic The gamma iron is shown in figure
Question 277
The coke in the charge of blast furnace
A. Controls the grade of pig iron
B. Acts as an iron bearing mineral
C. Supplies heat to reduce ore and melt the iron
D. Forms a slag by combining with impurities
View Answer
Answer: Option C
Explanation:
The coke in the charge of blast furnace Supplies heat to reduce ore and melt the iron The coke is a source of carbon monoxide which will reduce the iron oxide in the ore to iron and the carbon monoxide oxidizes to carbon dioxide. The limestone acts as a flux to remove other impurities and help the iron physically separate from the rest of the burden.
Question 278
The crystal of alpha iron is
A. Body centered cubic
B. Face centered cubic
C. Hexagonal close packed
D. Cubic structure
View Answer
Answer: Option A
Explanation:
The crystal of alpha iron is Body centered cubicAlpha iron is shown in figure 39. Which of the following alloys does not contain tin?A. White metalB. Solder admiraltyC. Fusible metalD. Phosphor bronzeAnswer & SolutionDiscuss in Board Save for LaterAnswer & SolutionAnswer: Option A White metal does not contain tin40. Railway rails are normally made ofA. Mild steelB. Alloy steelC. High carbonD. Tungsten steelAnswer & SolutionDiscuss in Board Save for LaterAnswer & SolutionAnswer: Option C Railway rails are subject to very high stresses, that's why it is made out from high carbon steel1234567891011121314Read More Section(Engineering Materials)Each Section contains maximum 70 questions. To get more questions visit other sections.Engineering Materials - Section 1Engineering Materials - Section 2Engineering Materials - Section 3Engineering Materials - Section 4
Question 279
Railway rails are normally made of
A. Mild steel
B. Alloy steel
C. High carbon
D. Tungsten steel
View Answer
Answer: Option C
Explanation:
Railway rails are subject to very high stresses, that's why it is made out from high carbon steel
Question 280
A specimen of aluminium metal when observed under microscope shows
A. B.C.C. crystalline structure
B. F.C.C. crystal structure
C. H.C.P. structure
D. A complex cubic structure
View Answer
Answer: Option B
Explanation:
A specimen of aluminium metal when observed under microscope shows F.C.C. crystal structure
Question 281
The correct sequence for descending order of machinability is
A. Grey cast iron, low carbon steel, wrought iron
B. Low carbon steel, grey cast iron, wrought iron
C. Wrought iron, low carbon steel, grey cast iron
D. Wrought iron, grey cast iron, low carbon steel
View Answer
Answer: Option A
Explanation:
The correct sequence for descending order of machinability is Grey cast iron, low carbon steel, wrought iron
Question 282
The ability of a material to resist fracture due to high impact loads, is called
A. Strength
B. Stiffness
C. Toughness
D. Brittleness
View Answer
Answer: Option C
Explanation:
toughness is the ability of a material to absorb energy and plastically deform without fracturing. toughness is the amount of energy per unit volume that a material can absorb before rupturing.
Question 283
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
View Answer
Answer: Option A
Explanation:
Substitutional solid solution strengthening occurs when the solute atom is large enough that it can replace solvent atoms in their lattice positions.Brass (alloy of copper and zinc) is an example of Substitutional solid solution
Question 284
Carbon in iron is an example of
A. Substitutional solution
B. Interstitial solid solution
C. Intermetallic compounds
D. All of the above
View Answer
Answer: Option B
Explanation:
The atoms crowd into the interstitial sites, causing the bonds of the solvent atoms to compress and thus deform.Carbon in iron is an example of Interstitial solid solution
Question 285
An important property of high silicon (12-18%) cast iron is the high
A. Hardness
B. Brittleness
C. Plasticity
D. Ductility
View Answer
Answer: Option A
Explanation:
High silicon iron-based alloys are excellent corrosion resistant materials with advantages of superior corrosion resistant properties, low cost and saving on noble metals such as nickel and chromium.When containing 14.5% or more silicon, the corrosion resistance of these iron-based alloys is better than that of some cast irons containing a significant amount of chromium, nickel and/or molybdenum, and even than that of certain nickel based alloys in some severe corrosion conditions.
Question 286
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
View Answer
Answer: Option B
Explanation:
Properties of gray cast ironIt has Good machinabilityIt has Good resistance to galling and wearIt has Good ductility
Question 287
The unique property of cast iron is its high
A. Malleability
B. Ductility
C. Surface finish
D. Damping characteristics
View Answer
Answer: Option D
Explanation:
There are several properties about cast iron is listed below:It has three to five times more compression strength compared to steelIt has Good machinability (gray cast iron)It has excellent anti-vibration (or damping) properties hence it is used to make machine framesIt has good SensibilityIt has excellent resistance to wearIt has constant Mechanical properties between 20 to 350 degree CelsiusIt has very low notch sensitivityIt has Low stress concentrationIt bears Low costIt is DurabilityIt has Resistance to deformation
Question 288
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
View Answer
Answer: Option B
Explanation:
Nickel and chromium in steel help in Providing corrosion resistance and Providing high strength at elevated temperatures and Raising the elastic limit
Question 289
Annealing of white cast iron results in production of
A. Malleable iron
B. Nodular iron
C. Spheroidal iron
D. Grey iron
View Answer
Answer: Option A
Explanation:
Malleable iron is obtained by the heat treatment of white iron so the hard iron carbide structure of ledeburite is converted to a matrix of ferrite or pearlite and graphite is precipitated within the iron. This form of graphite is sometimes referred to as tempered carbon.
Question 290
Beryllium bronze has
A. High yield point
B. High fatigue limit
C. Both (A) and (B)
D. None of these
View Answer
Answer: Option C
Explanation:
Beryllium bronze is a copper-base alloy containing beryllium. Beryllium bronze has high yield point and high fatigue limit
Question 291
The type of space lattice found in gamma-iron is
A. Face centered cubic space lattice
B. Body centered cubic space lattice
C. Close packed hexagonal space lattice
D. None of these
View Answer
Answer: Option A
Explanation:
the gamma iron (γ) is a face-centered cubic (FCC).
Question 292
The type of space lattice found in alpha-iron is
A. Face centered cubic space lattice
B. Body centered cubic space lattice
C. Close packed hexagonal space lattice
D. None of these
View Answer
Answer: Option B
Explanation:
The alpha iron (α) is a body-centered cubic (BCC).
Question 293
The maximum internal diameter of a blast furnace is about
A. 3 m
B. 6 m
C. 9 m
D. 12 m
View Answer
Answer: Option C
Explanation:
The maximum internal diameter of a blast furnace is about 9m
Question 294
The hardness of steel depends upon the
A. Amount of cementite it contains
B. Amount of carbon it contains
C. Contents of alloying elements
D. Method of manufacture of steel
View Answer
Answer: Option A
Explanation:
The hardness of steel depends upon the Amount of cementite it contains
Question 295
The aluminium alloy made by melting aluminium with 2 to 10% magnesium and 1.75% copper is called
A. Duralumin
B. Y-alloy
C. Magnalium
D. Hindalium
View Answer
Answer: Option C
Explanation:
The aluminium alloy made by melting aluminium with 2 to 10% magnesium and 1.75% copper is called magnalium
Question 296
A steel containing 16 to 18% chromium and about 0.12% carbon is called
A. Ferritic stainless steel
B. Austenitic stainless steel
C. Martenistic stainless steel
D. Nickel steel
View Answer
Answer: Option A
Explanation:
A steel containing 16 to 18% chromium and about 0.12% carbon is called Ferritic stainless steel
Question 297
Which of the following is added in low carbon steels to prevent them from becoming porous?
A. Sulphur
B. Phosphorus
C. Manganese
D. Silicon
View Answer
Answer: Option D
Explanation:
Silicon increases strength and hardness but to a lesser extent than manganese. It is one of the principal deoxidizers used in the making of steels to improve soundness, silicon is detrimental to surface quality, especially in the low carbon, resulphurized grades. It aggravates cracking tendencies when the carbon content is fairly high.
Question 298
The correct composition of Babbitt metal is
A. 87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
B. 90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
C. 87% Sn, 4% Cu, 8% Sb, 1% Al
D. 82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
View Answer
Answer: Option A
Explanation:
White metal alloys are those which are light-coloured and generally have a lead or tin base. These alloys are known as Babbitt metalBabbitt metal contains 87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
Question 299
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 deoxidized in the ladle with silicon and aluminium
D. In which carbon is completely burnt
View Answer
Answer: Option C
Explanation:
Killed steels are those steels Which are deoxidized in the ladle with silicon and aluminium
Question 300
Tin base white metals are used where the bearings are subjected to
A. Large surface wear
B. Elevated temperatures
C. Light load and pressure
D. High pressure and load
View Answer
Answer: Option A
Explanation:
Pure metals are soft, tough and ductile with a high coefficient of friction. Intermetallic compounds are hard and wear-resistant but brittle. By themselves, these do not make ideal bearing materials. The white metals are any of several light-colored alloys used as a base for plated silverware, ornaments or novelties, as well as any of several lead-based or tin-based alloys used for things like bearings, jewellery, miniature figures, fusible plugs, some medals and metal type.
Question 301
Elinvar, an alloy used in precision instruments, hair springs for watches, etc. contains the following element as principal alloying element
A. Iron
B. Copper
C. Aluminium
D. Nickel
View Answer
Answer: Option D
Explanation:
Elinvar is a nickel-iron alloy notable for having a modulus of elasticity which does not change much with temperature changes.Elinvar originally consisted of 52% iron, 36% nickel, and 12% chromium.It is almost non-magnetic, and corrosion resistant.
Question 302
Which of the following statement is incorrect about duralumin?
A. It is prone to age hardening
B. It can be forged
C. It has good machining properties
D. It is lighter than pure aluminium
View Answer
Answer: Option D
Explanation:
In addition to aluminum, the main materials in duralumin are copper, manganese and magnesium.Although the addition of copper improves strength, it also makes these alloys susceptible to corrosion. For sheet products, corrosion resistance can be greatly enhanced by metallurgical bonding of a high-purity aluminium surface layer. These sheets are referred to as alclad, and are commonly used by the aircraft industry
Question 303
Pearlite is a combination of
A. Ferrite and cementite
B. Cementite and gamma iron
C. Ferrite and austenite
D. Ferrite and iron graphite
View Answer
Answer: Option A
Explanation:
Pearlite is a combination of Ferrite and cementite
Question 304
Austenite is a combination of
A. Ferrite and cementite
B. Cementite and gamma iron
C. Ferrite and austenite
D. Ferrite and iron graphite
View Answer
Answer: Option B
Explanation:
Austenite is a combination of Cementite and gamma iron
Question 305
Which of the following is the binding material in cemented carbides?
A. Cobalt
B. Nickel
C. Vanadium
D. Iron
View Answer
Answer: Option A
Explanation:
Cobalt is the binding material in cemented carbides
Question 306
Which of the following statement is correct?
A. The product produced by blast-furnace is called cast iron
B. The pig iron is the name given to the product produced by cupola
C. The cast iron has high tensile strength
D. The chilled cast iron has no graphite
View Answer
Answer: Option D
Explanation:
Chilled cast iron. Iron-carbon alloy with low graphitization factor so that chill occurs forming a graphite-free structure. In order to achieve chilling, the silicon content is set to a low level depending on the wall thickness of the casting; the carbon content is approx. 2.5 to 3.8%.
Question 307
Monel metal contains
A. 63 to 67% nickel and 30% copper
B. 88% copper and 10% tin and rest zinc
C. Alloy of tin, lead and cadmium
D. Malleable iron and zinc
View Answer
Answer: Option A
Explanation:
Monel metal contains 63 to 67% nickel and 30% copper
Question 308
Inconel is an alloy of
A. Nickel, chromium and iron
B. Nickel, copper
C. Nickel, Chromium
D. Nickel, zinc
View Answer
Answer: Option A
Explanation:
Inconel is a family of austenitic nickel-chromium-based superalloys. Inconel alloys are oxidation-corrosion-resistant materials well suited for service in extreme environments subjected to pressure and heat.
Question 309
Manganese in steel increases its
A. Tensile strength
B. Hardness
C. Ductility
D. Fluidity
View Answer
Answer: Option A
Explanation:
The effect of manganese in improving the mechanical properties of steel depends on its carbon content. Manganese also reduces the critical cooling rate during hardening, meaning it increases the hardenability of steel. Its effect on hardenability is higher than other alloying elements
Question 310
Free cutting steels
A. Contain carbon in free from
B. Require minimum cutting force
C. Is used where rapid machining is the prime requirement
D. Can be cut freely
View Answer
Answer: Option C
Explanation:
Free cutting steels is used where rapid machining is the prime requirement
Question 311
Tungsten in high speed steel provides
A. Hot hardness
B. Toughness
C. Wear resistance
D. Sharp cutting edge
View Answer
Answer: Option A
Explanation:
Tungsten is a good carbide former that prevents grain growth, enhances toughness and increases red hardness and high temperature strength. Tungsten is used in hot forming tool steels and high-speed steels.
Question 312
1841 high speed steel contains
A. Vanadium 4%, chromium 18% and tungsten 1%
B. Vanadium 1%, chromium 4% and tungsten 18%
C. Vanadium 18%, chromium 1% and tungsten 4%
D. None of the above
View Answer
Answer: Option B
Explanation:
1841 high speed steel contains Vanadium 1%, chromium 4% and tungsten 18%
Question 313
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
View Answer
Answer: Option A
Explanation:
Nickel (Ni): Nickel is added in large amounts, over about 8%, to high Chromium stainless steels to form the most important class of corrosion and heat resisting steels.
Question 314
Depth of hardness of steel is increased by addition of
A. Nickel
B. Chromium
C. Tungsten
D. Vanadium
View Answer
Answer: Option B
Explanation:
Most stainless steel contains about 18 percent chromium; it is what hardens and toughens steel and increases its resistance to corrosion, especially at high temperatures
Question 315
By severely deforming a metal in a particular direction it becomes
A. Ductile
B. Malleable
C. Homogeneous
D. Anisotropic
View Answer
Answer: Option D
Explanation:
Anisotropy, is the property of being directionally dependent, which implies different properties in different directions, as opposed to isotropy.
Question 316
Iron-carbon alloys containing carbon ________ 4.3% are known as hyper-eutectic cast irons.
A. Equal to
B. Less than
C. More than
D. None of these
View Answer
Answer: Option C
Explanation:
Iron-carbon alloys containing carbon more than 4.3% are known as hyper-eutectic cast irons.hypereutectic cast iron (>4.3 % C).
Question 317
Which of the following statements are true for annealing of steels?
A. Steels are heated to 500 to 700°C
B. Cooling is done slowly and steadily
C. Internal stresses are relieved
D. All of these
View Answer
Answer: Option D
Explanation:
annealing of steels Increased cold shaping possibilities because intermediate annealing can be utilized to improve the forming properties after the material is compressed during other operations such as cold heading.annealing of steels Reduced chance of distortion during secondary operations such as machining.annealing of steels Controlled atmosphere annealing decreases the chance of oxidation to annealed parts.annealing of steels Improved reaction time and greater control of emergency product need fulfillment.
Question 318
Which is false statement about annealing? Annealing is done to
A. Relieve stresses
B. Harden steel slightly
C. Improve machining characteristic
D. Soften material
View Answer
Answer: Option B
Explanation:
annealing of steels Increased cold shaping possibilities because intermediate annealing can be utilized to improve the forming properties after the material is compressed during other operations such as cold heading.annealing of steels Reduced chance of distortion during secondary operations such as machining.annealing of steels Controlled atmosphere annealing decreases the chance of oxidation to annealed parts.annealing of steels Improved reaction time and greater control of emergency product need fulfillment.
Question 319
Eutectoid reaction occurs at
A. 600°C
B. 723°C
C. 1147°C
D. 1493°C
View Answer
Answer: Option B
Explanation:
in eutectoid reaction, the austenite transforms into a phase mixture of ferrite (containing 0.76% C) and cementite. This phase mixture is known as pearlite. The eutectoid reaction occurs at a constant temperature. This is known as eutectoid temperature and is 727°C
Question 320
When steel containing less than 0.8% carbon is cooled slowly from temperatures above or within the critical range, it consists of
A. Mainly ferrite
B. Mainly pearlite
C. Ferrite and pearlite
D. Pearlite and cementite
View Answer
Answer: Option C
Explanation:
When steel containing less than 0.8% carbon is cooled slowly from temperatures above or within the critical range, it consists of Ferrite and pearlite
Question 321
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 helps in raising the elastic limit and improve the resilience and ductility
D. Tungsten in steels improves magnetic properties and hardenability
View Answer
Answer: Option A
Explanation:
Aluminum metal is used to make many parts produced by precision machining, and is finding increasing application in automotive because of its light weight and high strength to weight ratio.
Question 322
Which of the following metal shrinks most from molten state to solid state?
A. Cast iron
B. Cast steel
C. Brass
D. Admiralty metal
View Answer
Answer: Option D
Explanation:
Admiralty metal is an alloy of not less than 70 percent copper, about 1 percent tin, small amounts of other elements, and the balance zinc; tin brass.Admiralty metal shrinks most from molten state to solid state
Question 323
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
A. 50 : 50
B. 30 : 70
C. 70 : 30
D. 40 : 60
View Answer
Answer: Option B
Explanation:
Admiralty brass used for steam condenser tubes contains 30% of copper and 70% of zinc
Question 324
Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio
A. 50 : 20 : 20 : 10
B. 40 : 30 : 20 : 10
C. 50 : 20 : 10 : 20
D. 30 : 20 : 30 : 20
View Answer
Answer: Option A
Explanation:
The composition of alnico alloys is typically 50% of Iron, 20% of nickel,20% of aluminium and 10% of cobalt
Question 325
Heavy duty leaf and coil springs contain carbon of the following order
A. 0.20%
B. 0.50%
C. 0.80%
D. 1.00%
View Answer
Answer: Option D
Explanation:
Heavy duty leaf and coil springs contain 1.0% carbon
Question 326
Cold rolled steel sheets contain carbon of the following order
A. 0.10%
B. 0.20%
C. 0.40%
D. 0.60%
View Answer
Answer: Option A
Explanation:
Cold rolled steel sheets contains 0.1% carbon Cold Rolled Steel A rolling process at temperatures that are close to normal room temperature are used to create cold rolled steel. This increases the strength of the finished product through the use of strain hardening by as much as 20 %
Question 327
In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled
A. In still air
B. Slowly in the furnace
C. Suddenly in a suitable cooling medium
D. Any one of these
View Answer
Answer: Option B
Explanation:
In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled Slowly in the furnace
Question 328
Steel containing ferrite and pearlite is
A. Hard
B. Soft
C. Tough
D. Hard and tough
View Answer
Answer: Option B
Explanation:
Steel containing ferrite and pearlite is soft Ferrite is a form of pure iron with a body-centered cubic crystal structure, and occurs in low-carbon steel.Pearlite is a finely laminated mixture of ferrite and cementite present in cast iron and steel, formed by the cooling of austenite.
Question 329
Ductile cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. It is soft, tough and easily machined metal
D. Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
View Answer
Answer: Option D
Explanation:
Ductile cast iron Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the materialductile iron has much more impact and fatigue resistance, due to its nodular graphite inclusions.
Question 330
Which of the following steel making process is being adopted at Rourkela (in India) Steel Plant?
A. Bessemer process
B. Open hearth process
C. Electric process
D. LD process
View Answer
Answer: Option D
Explanation:
LD process is a steel making process is being adopted at Rourkela (in India) Steel Plant
Question 331
Quenching is not necessary when hardening is done by
A. Case hardening
B. Flame hardening
C. Nitriding
D. Any one of these
View Answer
Answer: Option C
Explanation:
Nitriding has a different hardening mechanism than the one caused by quenching a steel with an elevated level of carbon.Instead, the hardening is caused by the fine scale precipitation of alloying element nitrides which does not require quenching.
Question 332
Which is false statement about case hardening? Case hardening is done by
A. Electroplating
B. Cyaniding
C. Induction hardening
D. Nitriding
View Answer
Answer: Option A
Explanation:
Case Hardening, is a heat treatment process that produces a surface which is resistant to wear, while maintaining toughness and strength of the core.This treatment is applied to low carbon steel parts after machining, as well as high alloy steel bearings, gears, and other components.
Question 333
The machinability of aluminium increases when _________ is added to aluminium.
A. Copper
B. Magnesium
C. Silicon
D. Lead and bismuth
View Answer
Answer: Option D
Explanation:
The low-melting-point metals such as bismuth, lead, tin, and cadmium are added to aluminum to make free-machining alloys. lead is added at about the 0.5% level with the same amount as bismuth in some alloys to improve machinability.
Question 334
In high speed steels, manganese is used to tougher the metal and to increase its
A. Yield point
B. Critical temperature
C. Melting point
D. Hardness
View Answer
Answer: Option B
Explanation:
Manganese is used to Increases hardenability, ductility and wear resistance.Eliminates formation of harmful iron sulphides.Austenite stabilizer.
Question 335
Following elements have face-centered cubic structure
A. Gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
B. Mg, Zn, Ti, Zr, Br, Cd
C. A iron (below 910°C and between 1400 to 1539°C), W
D. All of the above
View Answer
Answer: Option A
Explanation:
This following elements have face-centered cubic structureGamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
Question 336
The crystal structure of brass is
A. F.C.C.
B. B.C.C.
C. H.C.P.
D. Orthorhombic crystalline structure
View Answer
Answer: Option A
Explanation:
The crystal structure of brass is F.C.C. Face-centered cubic (fcc or cF) refers to a crystal structure consisting of an atom at each cube corner and an atom in the center of each cube face.
Question 337
Which of the following has highest specific strength of all structural materials?
A. Magnesium alloys
B. Titanium alloys
C. Chromium alloys
D. Magnetic steel alloys
View Answer
Answer: Option B
Explanation:
Titanium alloys is used to control grain size growth, which improves toughness. Also transforms sulfide inclusions form elongated to globular, improving strength and corrosion resistance as well as toughness and ductility.Titanium alloys is a very strong, very lightweight metal that can be used alone or alloyed with steels. It is added to steel to give them high strength at high temperatures. Modern jet engines used titanium steels.
Question 338
Blast furnace produces following by reduction of iron ore
A. Cast iron
B. Pig iron
C. Wrought iron
D. Malleable iron
View Answer
Answer: Option B
Explanation:
Pig Iron is the iron obtained from the blast furnace. The content of iron in pig iron is very high, it is around 92% and the second largest composition of pig iron is carbon which is around 4%.
Question 339
Shock resistance of steel is increased by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
View Answer
Answer: Option C
Explanation:
Shock resistance of steel is increased by adding Nickel and chromium
Question 340
Corrosion resistance of steel is increased by adding
A. Chromium and nickel
B. Nickel and molybdenum
C. Aluminium and zinc
D. Tungsten and sulphur
View Answer
Answer: Option A
Explanation:
Chromium is a powerful alloying element in steel.It strongly increases the hardenability of steel, and markedly improves the corrosion resistance of alloys in oxidizing media. Nickel is added to steels to increase hardenability.
Question 341
Cobalt in steel
A. Improves wear resistance, cutting ability and toughness
B. Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties
C. Improves cutting ability and reduce hardenability
D. Gives ductility, toughness, tensile strength and anti corrosion property
View Answer
Answer: Option C
Explanation:
Cobalt in steel Improves cutting ability and reduce hardenability
Question 342
The electric process of steel making is especially adapted to
A. Alloy and carbon tool steel
B. Magnet steel
C. High speed tool steel
D. All of these
View Answer
Answer: Option D
Explanation:
Most of the world's steel is produced by the electric-arc method, which uses high-current electric arcs to melt steel scrap and convert it into liquid steel of specified chemical composition and temperature.This process is adapted to Alloy and carbon tool steel and Magnet steel and High speed tool steel
Question 343
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 anti-corrosion properties
View Answer
Answer: Option A
Explanation:
Chromium in steel Increases strength, hardness, hardenability, and toughness, as well as creep resistance and strength at elevated temperatures.It improves machinability and resistance to corrosion and it intensifies the effects of other alloying elements.In hot-work steels and high speed steels,it increases red-hardness properties
Question 344
A cold chisel is made of
A. Mild steel
B. Cast iron
C. H.S.S.
D. High carbon
View Answer
Answer: Option D
Explanation:
Cold chisels are made from carbon tool-steel, which is usually octagonal in cross-section. Tool-steel is used as it can be hardened to form a hard and tough cutting edge. To make a cold chisel heat the end of the bar of tool steel until it is bright red and hammer to the desired shape.
Question 345
Cast iron is characterized by minimum of following percentage of carbon
A. 0.20%
B. 0.80%
C. 1.30%
D. 2%
View Answer
Answer: Option D
Explanation:
Cast iron is a ferrous alloy which has more than 2% carbon in it.Though it can have any percentage of carbon between 2% to 6.67%, but practically it is in between 2% to 4% only.
Question 346
Eutectoid steel contains following percentage of carbon
A. 0.02%
B. 0.30%
C. 0.63%
D. 0.80%
View Answer
Answer: Option D
Explanation:
Eutectoid steel contains 0.8% of carbon
Question 347
Cast iron has
A. High tensile strength
B. Its elastic limit close to the ultimate breaking strength
C. High ductility
D. All of the above
View Answer
Answer: Option B
Explanation:
cast iron properties are listed below:It has three to five times more compression strength compared to steelIt has Good machinability (gray cast iron)It has excellent anti-vibration (or damping) properties hence it is used to make machine framesIt has good SensibilityIt has excellent resistance to wearIt has constant Mechanical properties between 20 to 350 degree CelsiusIt has very low notch sensitivityIt has Low stress concentrationIt bears Low costIt is DurabilityIt has Resistance to deformation
Question 348
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
View Answer
Answer: Option C
Explanation:
Most-common type of steel that contains about 0.1 to 0.3 percent carbon. In general, increase in the amount of carbon reduces ductility but increases tensile strength and the ability to harden through tempering.As an industry-wide practice, steel that does not contain any specified or standard amount of one or more alloying elements (such as chromium, molybdenum, nickel, titanium, vanadium) to be classified as alloy steel is called carbon steel
Question 349
High carbon steel carries carbon percentage
A. 0.1 to 0.3%
B. 0.3 to 0.6%
C. 0.6 to 0.8%
D. 0.8 to 1.5%
View Answer
Answer: Option D
Explanation:
High carbon steel carries carbon percentage of 0.8 to 1.5%
Question 350
According to Indian standard specifications, plain carbon steel designated by 40 C8 means that the carbon content is
A. 0.04%
B. 0.35 to 0.45%
C. 0.4 to 0.6%
D. 0.6 to 0.8%
View Answer
Answer: Option B
Explanation:
Carbon steel - carbon range 0.35 to 0.45%40c8 actually gives you the carbon and manganese value in the steel.this designation is mostly used for plain carbon steels.It's a percentage of Carbon (letter C) in the steel.
Question 351
Recrystallization temperature can be lowered by
A. Purification of metal
B. Grain refinement
C. Working at lower temperature
D. All of the above
View Answer
Answer: Option D
Explanation:
Recrystallization temperature can be lowered by Purification of metal and Grain refinement and Working at lower temperature
Question 352
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
View Answer
Answer: Option C
Explanation:
Ductility of a material has been defined as a ability of a material to undergo permanent deformation through elongation and reduction in cross-sectional area or bending at room temperature without fracturing.
Question 353
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
View Answer
Answer: Option A
Explanation:
Malleability is a physical property of metals that defines the ability to be hammered, pressed or rolled into thin sheets without breaking.
Question 354
Muntz metal contains copper and zinc in the ratio of
A. 50 : 50
B. 40 : 60
C. 60 : 40
D. 20 : 80
View Answer
Answer: Option C
Explanation:
Muntz metal is about 60% copper, 40% zinc
Question 355
Bronze contains
A. 70% copper and 30% zinc
B. 90% copper and 10% tin
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 75% copper and rest tin
View Answer
Answer: Option B
Explanation:
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.
Question 356
Which of the following statement is true about brittle fracture?
A. High temperature and low strain rates favour brittle fracture
B. Many metals with hexagonal close packed (H.C.P) crystal structure commonly show brittle fracture
C. Brittle fracture is always preceded by noise
D. Cup and cone formation is characteristic for brittle materials
View Answer
Answer: Option B
Explanation:
Brittle Fracture is the sudden, very rapid cracking of equipment under stress where the material exhibited little or no evidence of ductility or plastic degradation before the fracture occurs.metals with hexagonal close packed (H.C.P) crystal structure commonly show brittle fracture
Question 357
Brass contains
A. 70% copper and 30% zinc
B. 90% copper and 10% tin
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 75% copper and rest tin
View Answer
Answer: Option A
Explanation:
Brass contains 70% copper and 30% zinc
Question 358
Pick up wrong statement about wrought iron
A. It contains carbon of the order of 0 to 0.25%
B. It melts at 1535°C
C. It is very soft and ductile
D. It is made by adding suitable percentage of carbon to molten iron and subjecting the product to repeated hammering and rolling
View Answer
Answer: Option D
Explanation:
Some Properties of wrought iron is listed below:It contains carbon of the order of 0 to 0.25%It melts at 1535°CIt is very soft and ductile
Question 359
Maximum percentage of carbon in ferrite is
A. 0.03%
B. 0.06%
C. 0.10%
D. 0.25%
View Answer
Answer: Option A
Explanation:
Below 912 °C (1,674 °F) iron again adopts the BCC structure characteristic of α-iron, also called ferrite. The substance assumes a paramagnetic property. Carbon dissolves poorly in α-iron: no more than 0.021% by mass at 723 °C
Question 360
The ability of a material to resist softening at high temperature is known as
A. Creep
B. Hot tempering
C. Hot hardness
D. Fatigue
View Answer
Answer: Option C
Explanation:
hot hardness or red hardness corresponds to hardness of a material at high temperatures.As the temperature of material increases, hardness decreases and at some point a drastic change in hardness occurs
Question 361
The defect which takes place due to imperfect packing of atoms during crystallization is known as
A. Line defect
B. Surface defect
C. Point defect
D. None of these
View Answer
Answer: Option C
Explanation:
Point defects are where an atom is missing or is in an irregular place in the lattice structure.Point defects include self interstitial atoms, interstitial impurity atoms, substitutional atoms and vacancies
Question 362
The alloy used for making electrical resistances and heating elements is
A. Nichrome
B. Invar
C. Magnin
D. Elinvar
View Answer
Answer: Option A
Explanation:
The most common usage of nichrome is as resistance wire, although they are also used in some dental restorations (fillings) and in a few other applications
Question 363
The strength is the ability of a material to resist
A. Deformation under stress
B. Externally applied forces with breakdown or yielding
C. Fracture due to high impact loads
D. None of these
View Answer
Answer: Option B
Explanation:
The Strength of the material is defined as the quality or state of being physically strong, the capacity of an object or substance to withstand great force or pressure
Question 364
The stiffness is the ability of a material to resist
A. Deformation under stress
B. Fracture due to high impact loads
C. Externally applied forces with breakdown or yielding
D. None of the above
View Answer
Answer: Option A
Explanation:
Stiffness is defined as the property of a material which is rigid and difficult to bend.The example of stiffness is rubber band
Question 365
Which of the following statement is wrong?
A. Steel with 0.8% carbon is wholly pearlite
B. The amount of cementite increases with the increase in percentage of carbon in iron
C. A mechanical mixture of 87% cementite and 13% ferrite is called pearlite
D. The cementite is identified as round particles in the structure
View Answer
Answer: Option C
Explanation:
Pearlite is a Mixture of Ferrite and Cementite (alternately arranged as like pearls)obtain 100% pearlite at 727 deg.C.Soft Phase than Austenite but posses better strength than Ferrite.
Question 366
Delta iron occurs at temperature of
A. Room temperature
B. Above melting point
C. Between 1400°C and 1539°C
D. Between 910°C and 1400°C
View Answer
Answer: Option C
Explanation:
Delta iron occurs at temperture in between 1400°C and 1539°C
Question 367
Which of the following elements does not impart hardness to steel?
A. Copper
B. Chromium
C. Nickel
D. Silicon
View Answer
Answer: Option A
Explanation:
Copper is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.and it is not impart hardness to steel.
Question 368
The steel widely used for motor car crankshafts is
A. Nickel steel
B. Chrome steel
C. Nickel-chrome steel
D. Silicon steel
View Answer
Answer: Option B
Explanation:
Chrome steel are used for applications such bearings, tools, drills and utensils and crankshafts.The chromium component of chrome steel would only provide some corrosion resistance. Higher tensile strength steels are created by the addition of carbon.