1000+ Engineering Materials Multiple Choice Question Answer [Solved]

1. 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
Answer : B

2. Which is false statement about annealing? Annealing is done to
A. Relieve stresses
B. Harden steel slightly
C. Improve machining characteristic
D. Soften material
Answer : B

3. The ability of a material to resist softening at high temperature is known as
A. Creep
B. Hot tempering
C. Hot hardness
D. Fatigue
Answer : C

4. 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

5. 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
Answer : D

6. 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 %
Answer : B

7. There are fourteen atoms in a unit cell of
A. Body centred cubic space lattice
B. Face centred cubic space lattice
C. Close packed hexagonal space lattice
D. None of these
Answer : B

8. 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
Answer : A

9. 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
Answer : D

10. 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 %
Answer : C

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

12. 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
Answer : D

13. Weld decay is the phenomenon found with
A. Cast iron
B. Mild steel
C. Nonferrous materials
D. Stainless steel
Answer : D

14. 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
Answer : C

15. Paramagnetic alpha iron changes to gamma iron at
A. 770°C
B. 910°C
C. 1440°C
D. 1539°C
Answer : B

16. 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
Answer : C

17. Permalloy is a
A. Kind of stainless steel
B. None ferrous alloy
C. Polymer
D. Nickel and iron alloy having high permeability
Answer : D

18. Nimonic contains __________ percentage of nickel as that of Inconel.
A. Same
B. Less
C. More
D. None of these
Answer : A

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

20. 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
Answer : C

21. Recrystallisation temperature can be lowered by
A. Purification of metal
B. Grain refinement
C. Working at lower temperature
D. All of the above
Answer : D

22. 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
Answer : A

23. Foundry crucible is made of
A. Mild steel
B. German silver
C. Lead
D. Graphite
Answer : D

24. The following element can't impart high strength at elevated temperature
A. Manganese
B. Magnesium
C. Nickel
D. Silicon
Answer : B

25. 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
Answer : A

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

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

28. 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
Answer : D

29. 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
Answer : C

30. 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
Answer : D

31. The heat treatment process used for softening hardened steel is
A. Carburising
B. Normalising
C. Annealing
D. Tempering
Answer : D

32. Beryllium bronze has
A. High yield point
B. High fatigue limit
C. Both (A) and (B)
D. None of these
Answer : C

33. The alloy, mainly used for corrosion resistance in stainless steels is
A. Silicon
B. Manganese
C. Carbon
D. Chromium
Answer : D

34. The alloy used for making electrical resistances and heating elements is
A. Nichrome
B. Invar
C. Magnin
D. Elinvar
Answer : A

35. 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
Answer : B

36. 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
Answer : C

37. 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
Answer : C

38. 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

39. 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
Answer : A

40. Muntz metal contains copper and zinc in the ratio of
A. 50 : 50
B. 40 : 60
C. 60 : 40
D. 20 : 80
Answer : C

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

42. 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
Answer : C

43. Mild steel belongs to the following category
A. Low carbon steel
B. Medium carbon steel
C. High carbon steel
D. Alloy steel
Answer : A

44. Pipes for bicycle frames are made of
A. Cold rolled steel
B. Hot rolled steel
C. Forged steel
D. Cast steel
Answer : A

45. Cartridge brass can be
A. Cold rolled into sheets
B. Drawn into wires
C. Formed into tube
D. Any one of these
Answer : D

46. Age-hardening is related with
A. Stainless steel
B. Gun metal
C. German silver
D. Duralumin
Answer : D

47. 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
Answer : C

48. 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

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

50. When the steel is normalised, its
A. Yield point increases
B. Ductility decreases
C. Ultimate tensile strength increases
D. All of these
Answer : D