Metallurgy - Mechanical Engineering test questions

Metallurgy - Mechanical Engineering test questions

1) In steel, the pearlite phase is made up of alternate layers of

a) Cementite and martensite
b) Ferrite and martensite
c) Ferrite and cementite
d) Cementite and bainite

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ANSWER: c) Ferrite and cementite

2) Babbit is an alloy of

a) Sn and Cu
b) Cu and Zn
c) Sn, Cu, Sb, and Pb
d) Sn, Cu and Pb

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ANSWER: c) Sn, Cu, Sb, and Pb

3) Fatigue strength is least affected by

a) Magnitude of mean stress
b) Stress concentration
c) Frequency
d) Temperature

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ANSWER: c) Frequency

4) Good impact strength indicates

a) Good creep resistance
b) Good wear resistance
c) Good ductility
d) Good fatigue behaviour

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ANSWER: c) Good ductility

5) Which among the following type is magnetic allotrope of iron?

a) α
b) β
c) γ
d) λ

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ANSWER: a) α

6) For which of the following reasons is manganese is alloyed with low carbon steels?

a) To make them tough and hard
b) To increase corrosion resistance
c) To raise tensile strength
d) To improve machinability

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ANSWER: c) To raise tensile strength

7) Which of the following is a copper free alloy?

a) Muntz metal
b) German silver
c) Gun metal
d) White metal

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ANSWER: d) White metal

8) Chisel used for cutting steel sheets is usually

a) Normalised
b) Annealed
c) Hardened
d) Hardened and tempered

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ANSWER: d) Hardened and tempered

9) Which surface hardening process gives maximum hardness to the surface?

a) Cyaniding
b) Pack hardening
c) Nitriding
d) Induction hardening

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ANSWER: c) Nitriding

10) The metallic structure of mild steel is

a) Hexagonal closed packed
b) Cubic
c) Face centred cubic
d) Body centred cubic

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ANSWER: d) Body centred cubic

11) Which of the following statements is incorrect regarding ‘tempering’?

a) It improves ductility
b) It releases stresses
c) It improves machinability
d) It reduces hardness and brittleness

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ANSWER: c) It improves machinability

12) The product of cupola is called as

a) Cast iron
b) Wrought iron
c) Mild steel
d) Pig iron

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ANSWER: a) Cast iron

13) Pearlite appears as ……….. under microscope.

a) White
b) Dark
c) Light
d) Finger print

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ANSWER: d) Finger print

14) What do you mean by hardenability of steel?

a) Ability to withstand shocks
b) Ability of steel to resist abrasion, wear and penetration
c) Property which determines the depth of the hardened zone induced by quenching
d) None of the above

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ANSWER: c) Property which determines the depth of the hardened zone induced by quenching

15) How can the recrystallization temperature be lowered?

a) By grain refinement
b) By purification of metals
c) By working at lower temperature
d) All of the above

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ANSWER: d) All of the above

16) Which of the following statements is correct regarding ‘diamagnetic materials’?

a) These can be magnetised by eddy currents
b) These can be magnetised in one direction only
c) These are magnetised in direction opposite to that of the applied field
d) None of these

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ANSWER: c) These are magnetised in direction opposite to that of the applied field

17) Cold worked components are generally subjected to

a) Normalising
b) Tempering
c) Hardening
d) Annealing

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ANSWER: d) Annealing

18) Line imperfection in case of a crystal is also called as

a) Schottkv defect
b) Frenkel defect
c) Edge dislocation
d) None of these

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ANSWER: c) Edge dislocation

19) The maximum hardenability of any steel depends on

a) Chemical composition
b) Grain size
c) Carbon content
d) Alloying elements

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ANSWER: c) Carbon content

20) Which among the following is a correct statement?

a) A completely brittle metal will not fracture at elastic limit
b) In elastic materials, yield stress and tensile strength are practically identical
c) A metal which is brittle in tension may be ductile under hydrostatic compression
d) All materials undergo plastic deformation

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ANSWER: c) A metal which is brittle in tension may be ductile under hydrostatic compression

21) The correct statement in case of thermosetting plastics is

a) They are produced on synthesis basis
b) They soften on heating and can be moulded again
c) They permanently set with heat and cannot be deformed on heating it again
d) None of these

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ANSWER: c) They permanently set with heat and cannot be deformed on heating it again

22) Austenite is a solid solution of carbon in

a) λ iron
b) α iron
c) γ iron
d) β iron

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ANSWER: c) γ iron

23) Gibb’s phase rule is given by

Where, F = number of degrees of freedom; C = number of components; n = number of external factors; P = number of phases in equilibrium

a) F = C + n – P
b) F = C + 2n – P
c) F = C + 2n + P
d) F = C + n – 2P

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ANSWER: a) F = C + n – P

24) Which of the following statements is correct regarding ‘subzero treatment of steel’?

a) It is used to reduce the retained austenite in hardened steel
b) It is used to suppress martensite transformation
c) It is performed after hardening operation to induce temper brittleness
d) All of the above

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ANSWER: a) It is used to reduce the retained austenite in hardened steel

25) Mechanical properties of steel castings can be improved by which of the following heat treatment processes?

a) Phase annealing
b) Incomplete hardening
c) Tempering
d) All of the above

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ANSWER: a) Phase annealing

26) Rockwell reading is a measure of the penetration caused by

a) Minor load only
b) Major load only
c) Both minor load and major lad
d) None of the above

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ANSWER: b) Major load only

27) Structure of hypereutectoid steels comprises

a) Cementite only
b) Phases of cementite and pearlite
c) Pearlite only
d) Phases of ferrite and cementite

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ANSWER: b) Phases of cementite and pearlite

28) In 18-4-1 HSS, what is the percentage of chromium?

a) 1%
b) 4%
c) 18%
d) Cannot be determined

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ANSWER: c) 18%

29) Addition of sulphur to steel increases

a) Wear resistance
b) Corrosion resistance
c) Machinability
d) Hardness

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ANSWER: c) Machinability

30) What is Bakelite?

a) A silicon varnish
b) A catalyst
c) A thermoplastic resin
d) A phenol formaldehyde resin

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ANSWER: d) A phenol formaldehyde resin