Engineering Materials
Q. Which of the following parameters can be obtained by tension test of a standard specimen?
a) Proportional Limit
b) Yield Strength
c) Percentage Reduction in area
d) All of the mentioned
.
Answer: A
Explanation: Tension test determines the parameters related to stress strain curve and also reduction and elongation in area and length can be found respectively.
Q. Proportional Limit is defined as the stress at which the stress strain curves begins to deviate from the straight line.
a) True
b) False
.
Answer: A
Explanation: Proportional limit is the point of deviation in stress strain curve.
Q. Which of the following is the definition of Compliance?
a) Inverse of Rigidity
b) Inverse of Stiffness
c) Proportional to elastic Limit
d) None of the mentioned
.
Answer: B
Explanation: Compliance is a parameter which is the inverse of stiffness.
Q. Yield strength is defined as the maximum stress at which a marked increase in elongation occurs without increase in________
a) Load
b) Strength
c) Toughness
d) Hardness
.
Answer: A
Explanation: Yield strength is the strength at which strain increases. Now as the strength is constant, therefore load is constant.
Q. For the materials which do not exhibit a well-defined yield points, the yield strength is defined as the stress corresponding to a permanent set of how much percentage of gauge length?
a) 0.1
b) 0.2
c) 0.3
d) 0.4
.
Answer: B
Explanation: Generally for all the practical purpose, an offset of 0.2% of gauge length is considered.
Q. Proof strength is defined as the stress which will produce a permanent extension of how much percentage in the gauge length of the standard test specimen.
a) 0.1
b) 0.2
c) 0.3
d) 0.4
.
Answer: A
Explanation: Proof strength is used in design of fasteners. It corresponds to 0.1% permanent deformation of gauge length.
Q. All engineering materials are plastic.
a) True
b) False
.
Answer: A
Explanation: Yes all the existing engineering materials are plastic to some extent.
Q. Which of the following are true about plasticity?
a) Permanent Deformation
b) Ability to retain deformation under load or after removal of load
c) Plastic deformation is greater than elastic deformation
d) All of the mentioned
.
Answer: D
Explanation: This is the basic definition of plasticity.
Q. Which of the following is measure of stiffness?
a) Modulus of elasticity
b) Modulus of plasticity
c) Resilience
d) Toughness
.
Answer: A
Explanation: Stiffness is the ability of material to resist deformation under external load. Hence it is measured by modulus of elasticity.
Q.. Which of the following facts are true for resilience?
a) Ability of material to absorb energy when deformed elastically
b) Ability to retain deformation under the application of load or after removal of load
c) Ability of material to absorb energy when deformed plastically
d) None of the mentioned
.
Answer: A
Explanation: Toughness is ability to store energy till proportional limit during deformation and to release this energy when unloaded.
1Q. Modulus of resilience is defined as
a) Strain energy per unit volume
b) Strain energy per unit area
c) Independent of strain energy
d) None of the mentioned
.
Answer: A
Explanation: Modulus of resilience is strain energy per unit volume.
1Q. Which of the following are true for toughness
a) Ability of material to absorb energy before fracture
b) Measured by Izod & Charpy test
c) Decreases with the increase in temperature
d) All of the mentioned
.
Answer: D
Explanation: Toughness is measure of energy stored till fracture occurs. With rise of temperature, molecular bonds weakens and fracture occurs at a lesser load, hence area under stress strain curve decreases.
1Q. Malleability increases with temperature while ductility decreases with temperature.
a) True
b) False
.
Answer: A
Explanation: Malleability is the deformation under compressive load and hence with rise in temperature, the deformation increases and hence malleability increases.
1Q. Hardness is
a) Surface property
b) Resistance to abrasion
c) Depends upon resistance to plastic deformation of the material
d) All of the mentioned
.
Answer: D
Explanation: Hardness is a surface property which is the resistance of material to surface indentation. It depends upon resistance to plastic deformation.
Q. Ductile cast iron is
a) Also called nodular cast iron
b) Also called spheroidal graphite cast iron
c) Carbon is present in form of spherical nodules
d) All of the mentioned
.
Answer: D
Explanation: Ductile cast iron, also called as nodular cast iron or spheroidal cast iron consists of carbon in the form of spherical nodules in a ductile matrix.
Q. Grey Cast iron is formed when
a) Carbon content in the alloy exceeds the amount that can be dissolved
b) Carbon content in the alloy is less than the amount that can be dissolved
c) Carbon content in the alloy is equal to the amount that can be dissolved in the alloy
d) None of the mentioned
.
Q. White cast iron is formed when
a) Graphite flakes are formed
b) Most of the carbon content in the alloy forms iron carbide
c) No iron carbide is formed
d) None of the mentioned
.
Answer: B
Explanation:White cast iron is formed when most carbon in alloy forms iron carbide and there are no graphite flakes.
Q. The term high alloy steels is used for alloy steels containing more than ___ of alloying elements.
a) Q.%
b) 20%
c) 50%
d) 70%
.
Answer: A
Explanation: The term high alloy steels is used when alloying elements exceed Q.%.Low and medium alloy steels are those when this figure is less than Q.%.
Q. Which of the following are true about low carbon steels?
a) Carbon content < 0.3%
b) Also called as mild steel
c) Are soft and ductile
d) All of the mentioned
.
Answer: D
Explanation: Low carbon steels contain carbon <0.3%. Because of low carbon, it is soft and ductile.
Q. Which of the following are true for high carbon steels?
a) Carbon content=0.4%
b) Respond readily to heat treatments
c) Have much ductility as compared to low and medium carbon steels
d) Easy to weld
.
Answer: B
Explanation: High carbon steel have carbon % >0.5 and hence have less ductility. They are difficult to weld.
Q. Which of the following are true?
a) 7C4 grade steel is more ductile than Q.C4
b) Yield strength of 40C8 is greater than of 30C8
c) Hardness of 30C8 is greater than of 40C8
d) None of the mentioned
.
Answer: A
Explanation: The number before “C” indicates measure of carbon. Hence a) is true as higher the carbon, lower the ductility.
Q. In the designation “xCb” which of the following are true?
a) x indicates Q.0 times the average % of carbon
b) b indicates Q.0 times the average percentage of manganese
c) x indicates Q. times the average percentage of carbon while b indicates Q.0 times the average percentage of manganese
d) b indicates Q.0 times the average % of carbon
.
Answer: A
Explanation: X indicates Q.0 times carbon % and b indicates Q. times manganese %.
Q. Which of the steel in given options is best suited for auto mobile bodies and hoods?
a) 7C4
b) Q.C4
c) 30C8
d) 40C8
.
Answer: A
Explanation: For automobile application like manufacturing bodies, ductile material is preferred.
Q.. Which of the following steel given in options respond fastest and easily to heat treatment?
a) 7C4
b) Q.C4
c) 30C8
d) 40C8
.
Answer: D
Explanation: Alloys with higher carbon % respond willingly to heat treatment.
1Q. Which of the following given steels is popular with the name of machinery steel?
a) Low carbon steel
b) Medium carbon steel
c) High carbon steel
d) None of these
.
Answer: B
Explanation: It has ductility and can be heat treated easier than low carbon steel.
Q. Which of the following property is affected by heat treatment?
a) Hardness
b) Strength
c) Ductility
d) All of the mentioned
.
Answer: D
Explanation: Heat treatment involves changes in the micro structure and hence all the internal properties are effected.
Q. Annealing involves heating the component to a temperature
a) Slightly above the critical temperature
b) Equal to critical temperature
c) Slightly less than critical temperature
d) None of the mentioned
.
Answer: A
Explanation: In annealing, component is heated to a temperature above than critical temperature.
Q. Which of the following is true?
a) Rate of cooling in normalising is faster then in annealing
b) Annealing improves ductility
c) Normalising improves grain structure
d) All of the mentioned
.
Answer: D
Explanation: In annealing, the furnace is switched off and component cools slowly. In normalising, component is air cooled.
Q. Quenching
a) Consists of heating the component to critical temperature
b) Cooling rapidly
c) Increases hardness
d) All of the mentioned
.
Answer: D
Explanation: During quenching, component is rapidly cooled which leads to formation of martensite. Hence hardness increases.
Q. Tempering involves
a) Reheating the quenched component to a temperature greater than critical temperature
b) Increases the brittleness
c) Reheating the quenched component to a temperature equal to critical temperature
d) None of the mentioned
.
Answer: D
Explanation: Tempering involves reheating the quenched product to a temperature less than transformation range. It improves ductility and reduces brittleness.
Q. Silicon addition in spring steel increases its toughness.
a) True
b) False
.
Answer: A
Explanation: Silicon addition increases strength without lowering the ductility.
Q. Nickel addition in alloys
a) Increases toughness
b) Increases hardenability and impact resistance
c) Limit grain growth during heat treatment process
d) All of the mentioned
.
Answer: D
Explanation: Nickel addition increases toughness by limiting grain growth.
Q. Flame hardening involves
a) Heating the surface above the trAnswerformation range
b) Quenching after heating
c) Minimum case depth is 1mm
d) All of the mentioned
.
Answer: D
Explanation: Flame Hardening is a process of heating the surface with a flame above critical temperature and then quenching it.
Q. Induction hardening process involves
a) Heating surface by induction in field of invariable current
b) Case depth minimum of 2mm are produced
c) Heating surface by induction in field of alternating current
d) None of the mentioned
.
Answer: C
Explanation: Heating can only be done in presence of alternating current and not constant current.
Q.. Case carburising involves
a) Introducing carbon at surface layer
b) Heating range 880 to 980’C
c) Case depths up to 2mm are possible
d) All of the mentioned
.
Answer: D
Explanation: Case carburising involves introducing carbon at surface layer. Medium can be liquid, solid or gas and high case depths are possible.
1Q. Which of the following are not true for carbo nitriding?
a) Introducing carbon and nitrogen at surface layer
b) Component is heated in range of 650 to 920’C
c) Cyaniding is similar to carbo nitriding except that the medium is liquid
d) This process gives a lower wear resistance compared to case carburising process
.
Answer: D
Explanation: Carbo nitriding gives wear resistance greater than compared to case carburising.
1Q. Which of the following are true for nitriding?
a) Nascent oxygen is involved
b) Temperature range 490 to 590’C
c) Gaseous or liquid medium
d) All of the mentioned
.
Answer: D
Explanation: In nitriding nascent oxygen is acted on the surface of the product at a temperature of 490::590’C in a gaseous or liquid medium.
Q. Cast steel components do not exhibit the effect of directionality on mechanical properties.
a) True
b) False
.
Answer: A
Explanation: In casting process, there is no control over the fibre structure, thus non directional characteristics for cast steel components.
Q. During solidification, cast steel shrinks to quite a great extent
a) True
b) False
.
Answer: A
Explanation: Excessive contractions observed in cast steel.
Q. Relative density of aluminium is roughly _______ of steel
a) one-third
b) one-fifth
c) one-tenth
d) equal
.
Answer: A
Explanation: Aluminium alloy=Q.7 Steel=Q.Q.
Q. Which of the following statement is true
a) Cast aluminium alloys are specified by a four digit system while wrought alloys by a five digit system
b) Cast aluminium alloys are specified by a five digit system while wrought alloys by a four digit system
c) Cast aluminium alloys are specified by a six digit system while wrought alloys by a five digit system
d) Cast aluminium alloys are specified by a five digit system while wrought alloys by a six digit system
.
Answer: A
Explanation: Standard set for nomenclature.
Q. Which of the following are true for aluminium
a) Low specific gravity
b) Corrosion resistance
c) High thermal conductivity
d) All of the mentioned
.
Answer: D
Explanation: All are properties of aluminium.
Q. Is it possible to completely relieve the residual stresses in a cast steel product?
a) True
b) False
.
Answer: B
Explanation: Solidification results in great amount of residual stresses.
Q. Poor fluidity and contraction are compulsory to be taken into consideration while designing a cast steel product.
a) True
b) False
.
Answer: A
Explanation: Contraction affects to quite a extent in cast steel.
Q. In alloy 4450, 2nd digit represents?
a) average percentage of major alloying elements, halved and rounded off
b) average percentage of major alloying elements
c) average percentage of minor alloying elements, halved and doubled
d) average percentage of minor alloying elements
.
Answer: A
Explanation: Second digit is used to represent major alloying element.
Q. In alloy 4450, 4 represents?
a) Silicon
b) Aluminium
c) Manganese
d) Zinc
.
Answer: A
Explanation: In alloy nomenclature,1=Al;2=Cu;3=Mn;4=Si;5=Mg.
Q.. An aluminium alloy casting with Q.8% Cu, Q.0% Fe and 0.25% Mg
a) Alloy 2585
b) Alloy 3586
c) Alloy 2686
d) Alloy 3584
.
Answer: A
Explanation: 1st digit=2(Copper) ; 2nd digit=Q.8/2=5 ;3rd digit=8(Iron); 4th digit=5(Magnesium).
Q. Which of the following are true for copper alloys
a) Posses excellent thermal and electrical conductivity
b) Can be easily cast and machined
c) Has good corrosion resistance
d) All of the mentioned
.
Answer: D
Explanation: Properties of copper.
Q. Which of the following contain copper
a) bronze
b) gunmetal
c) monel metal
d) each of the mentioned
.
Answer: D
Explanation: All the mentioned alloys contain copper to some extent.
Q. Which of the following are true
a) Brass is costlier then copper
b) Brass has excellent corrosion resistance
c) Brass has good machinability
d) Brass has poor thermal conductivity
.
Answer: B
Explanation: Brass is a good thermal conductor,is cheaper and has poor machinability.
Q. As the amount of zinc increases
a) strength of brass increases and ductility decrease
b) strength of brass increases and ductility increase
c) strength of brass decreases and ductility increases
d) strength of brass decreases and ductility decreases
.
Answer: A
Explanation: Brass contains zinc and copper. Zinc affects strength with direct increase in strength with increase of zinc content.
Q. Which of the following are true for aluminium bronze
a) contain 5-Q.% aluminium
b) excellent corrosion and is also called imitation gold
c) difficult to cast
d) all of the mentioned
.
Answer: D
Explanation: Color of aluminium bronze is similar to gold. Other two are the properties of alloys.
Q. Which of the following statements for phosphorus bronze is true?
a) contains 0.2% phosphorus
b) phosphorus increases tensile strength
c) use for worm wheels and bearings
d) all of the mentioned
.
Answer: D
Explanation: It has good tensile strength, corrosion resistance and is used for bearings.
Q. Gunnmetal is an alloy of copper which __ % tin and __% zinc.
a) Q.,2
b) 2,Q.
c) 4,5
d) 5,4
.
Answer: A
Explanation: Zinc is used to improve fluidity during casting and hence is kept lesser than tin.
Q. Monel metal is a copper nickel alloy of __% nickel and __%copper.
a) 32,65
b) 65,32
c) 20,80
d) 80,20
.
Answer: B
Explanation: Composition.
Q. Which of the following are true for die casting alloys?
a) this process consists of forcing the molten metal into a closed metal die
b) process used for a metal with low melting point
c) surface finish is excellent
d) all of the mentioned
.
Answer: D
Explanation: Characteristics of die casting alloys.
Q. Ceramics consist of
a) ionic & covalent bonding
b) covalent bonding
c) hydrogen bonding
d) none of the mentioned
.
Answer: A
Explanation: Ceramics consists of ionic and covalent bonds only.There is no hydrogen compound so no case of H boding.
Q. All ceramics contain clay.
a) True
b) False
.
Answer: B
Explanation: No this may sound convincing but all ceramics don’t contain clay.
Q. The densities of ceramics are low.
a) True
b) False
.
Answer: A
Explanation: In ceramics, different oxides and carbides are not compactly bonded.
Q. There are small voids in ceramics structure.
a) True
b) False
.
Answer: A
Explanation: Compounds are less compactly bonded and hence voids are formed.
Q. Which of the following properties are true for ceramics.
a) light weight construction with low inertia force
b) excellent wear
c) lower friction loss
d) all of the mentioned
.
Answer: D
Explanation: Properties of ceramics.
Q. Paraffin wax is represented by
a) C18H35
b) C18H40
c) C18H36
d) None of the mentioned
.
Answer: D
Explanation: Paraffin wax in a semi solid stage is represented by C18H3Q.
Q. A thermoplastic material has a linear polymer chain while a thermosetting plastic has a crosslinked polymer chain.
a) True
b) False
.
Answer: A
Explanation: Given statement is true thats why thermoplastic can be remoulded while thermosettings can’t be.
Q. Which of the following is a thermosetting polymer?
a) PVC
b) PTFE
c) Nylon
d) Polyesters
.
Answer: D
Explanation: a), b) and c) consist of linear structures while polyester consists of cross linked and hence is a thermosetting polymer.
Q. Teflon has very high coefficient of resistance.
a) True
b) False
.
Answer: B
Explanation: Teflon is very smooth and has coefficient of friction as low as 0.0Q.
Q.. Viscoelastic materials at low temperatures show no change in its strain with change in stress.
a) True
b) False
.
Answer: B
Explanation: Viscoelastic materials follow Hooke’s law at intermediate temperatures.
