1000+ Engineering Materials Multiple Choice Question Answer [Solved]

1. The hardness of steel increases if it contains
A. Pearlite
B. Ferrite
C. Cementite
D. Martensite
Answer : C

2. 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
Answer : A

3. 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
Answer : C

4. Railway rails are normally made of
A. Mild steel
B. Alloy steel
C. High carbon
D. Tungsten steel
Answer : C

5. 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 anticorrosion properties
Answer : D

6. 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
Answer : B

7. The defect which takes place due to imperfect packing of atoms during crystallisation is known as
A. Line defect
B. Surface defect
C. Point defect
D. None of these
Answer : C

8. Nodular cast iron is produced by adding ________ to the molten cast iron.
A. Nickel
B. Chromium
C. Copper
D. Magnesium
Answer : D

9. Babbitt metal is a
A. Lead base alloy
B. Copper base alloy
C. Tin base alloy
D. Cadmium base alloy
Answer : C

10. 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
Answer : B

11. 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
Answer : B

12. Which of the following property is desirable for materials used in tools and machines?
A. Elasticity
B. Plasticity
C. Ductility
D. Malleability
Answer : A

13. The hardness of steel increases if it contains
A. Austenite
B. Martensite
C. Pearlite
D. Cementite
Answer : B

14. 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
Answer : B

15. 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
Answer : D

16. Sulphur in pig iron tends to make it
A. Hard
B. Soft
C. Ductile
D. Tough
Answer : A

17. 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
Answer : D

18. 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
Answer : B

19. Machining properties of steel are improved by adding
A. Sulphur, lead, phosphorous
B. Silicon, aluminium, titanium
C. Vanadium, aluminium
D. Chromium, nickel
Answer : A

20. Crystal structure of a material is, generally, examined by
A. Naked eye
B. Optical microscope
C. Metallurgical microscope
D. X-ray techniques
Answer : D

21. Which of the following is used for bearing liner?
A. Gun metal
B. Bronze
C. Bell metal
D. Babbitt metal
Answer : D

22. In low carbon steels, presence of small quantities of sulphur improves
A. Weldability
B. Formability
C. Machinability
D. Hardenability
Answer : C

23. The metal suitable for bearings subjected to light loads, is
A. Silicon bronze
B. White metal
C. Monel metal
D. Phosphor bronze
Answer : D

24. 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 %
Answer : C

25. 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
Answer : D

26. Following elements have face-centred 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
Answer : A

27. Grey cast iron has
A. Carbon in the form of free graphite
B. High tensile strength
C. Low compressive strength
D. All of these
Answer : A

28. The presence of sulphur in pig iron makes
A. It easily machinable
B. It brittle
C. It hard
D. The casting unsound
Answer : D

29. Dye penetrant method is generally used to locate
A. Core defects
B. Surface defects
C. Superficial defects
D. Temporary defects
Answer : B

30. The material in which the atoms are arranged chaotically, is called
A. Amorphous material
B. Mesomorphous material
C. Crystalline material
D. None of these
Answer : A

31. The percentage of carbon in low carbon steel is
A. 0.05 %
B. 0.15 %
C. 0.3 %
D. 0.5 %
Answer : B

32. The metallic structure of mild steel is
A. Body centred cubic
B. Face centred cubic
C. Hexagonal close packed
D. Cubic structure
Answer : A

33. Macrostructure of a material is, generally, examined by
A. Naked eye
B. Optical microscope
C. Metallurgical microscope
D. X-ray techniques
Answer : A

34. 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
Answer : C

35. 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
Answer : C

36. Corrosion resistance of steel is increased by adding
A. Chromium and nickel
B. Nickel and molybdenum
C. Aluminium and zinc
D. Tungsten and sulphur
Answer : A

37. 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
Answer : C

38. Melting point of iron is
A. 1539°C
B. 1601°C
C. 1489°C
D. 1712°C
Answer : A

39. The crystal of alpha iron is
A. Body centered cubic
B. Face centered cubic
C. Hexagonal close packed
D. Cubic structure
Answer : A

40. Which of the following is added in low carbon steels to prevent them from becoming porous?
A. Sulphur
B. Phosphorus
C. Manganese
D. Silicon
Answer : D

41. Which of the following elements does not impart hardness to steel?
A. Copper
B. Chromium
C. Nickel
D. Silicon
Answer : A

42. Eutectoid steel consists of
A. Wholly pearlite
B. Wholly austenite
C. Pearlite and ferrite
D. Pearlite and cementite
Answer : A

43. Eutectoid reaction occurs at
A. 600°C
B. 723°C
C. 1147°C
D. 1493°C
Answer : B

44. 'Killed steels' are those steels
A. Which are destroyed by burning
B. Which after their destruction are recycled to produce fresh steel
C. Which are deoxidised in the ladle with silicon and aluminium
D. In which carbon is completely burnt
Answer : C

45. Brass is an alloy of
A. Copper and zinc
B. Copper and tin
C. Copper, tin and zinc
D. None of these
Answer : A

46. 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
Answer : B

47. 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
Answer : A

48. In grey cast iron, carbon is present in the form of
A. Cementite
B. Free carbon
C. Flakes
D. Spheroids
Answer : C

49. 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
Answer : D

50. The maximum internal diameter of a blast furnace is about
A. 3 m
B. 6 m
C. 9 m
D. 12 m
Answer : C