1000+ Engineering Materials MCQ for SSC CPO [Solved]

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

2. The type of space lattice found in alpha-iron is
A. Face centred cubic space lattice
B. Body centred cubic space lattice
C. Close packed hexagonal space lattice
D. None of these
Answer : B

3. Free cutting steels
A. Are used where ease in machining is the criterion
B. Contain carbon in free form
C. Require least cutting force
D. Do not exist
Answer : A

4. In induction hardening ________ is high.
A. Current
B. Voltage
C. Frequency
D. Temperature
Answer : C

5. An alloy of copper, tin and zinc is known as
A. Brass
B. Bronze
C. Gun metal
D. Muntz metal
Answer : C

6. The ability of a material to absorb energy in the plastic range is called
A. Resilience
B. Creep
C. Fatigue strength
D. Toughness
Answer : A

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

8. Hematite iron ore contains iron about
A. 30 %
B. 45 %
C. 55 %
D. 70 %
Answer : D

9. Wrought iron is
A. Hard
B. High in strength
C. Highly resistant to corrosion
D. Heat treated to change its properties
Answer : C

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

11. 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
Answer : C

12. 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
Answer : B

13. 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
Answer : B

14. 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
Answer : D

15. The ability of a material to resist fracture due to high impact loads, is called
A. Strength
B. Stiffness
C. Toughness
D. Brittleness
Answer : C

16. 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
Answer : D

17. '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

18. 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
Answer : C

19. 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

20. 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

21. 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
Answer : A

22. 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
Answer : A

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

24. 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

25. Which of the following property is desirable in parts subjected to shock and impact loads?
A. Strength
B. Stiffness
C. Brittleness
D. Toughness
Answer : D

26. 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

27. The coordination number of a face centred cubic space lattice is
A. Six
B. Twelve
C. Eighteen
D. Twenty
Answer : B

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

29. 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

30. 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
Answer : A

31. 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
Answer : B

32. 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
Answer : B

33. The percentage of carbon in pig iron varies from
A. 0.1 to 1.2%
B. 1.5 to 2.5%
C. 2.5 to 4%
D. 4 to 4.5%
Answer : D

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

35. In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.
A. Sulphur
B. Phosphorus
C. Manganese
D. Silicon
Answer : B

36. 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
Answer : C

37. Which of the following element results in presence of free graphite in C.I.?
A. Carbon
B. Sulphur
C. Silicon
D. Manganese
Answer : C

38. 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

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

40. 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

41. Recrystallisation 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
Answer : B

42. 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

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

44. 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
Answer : C

45. 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
Answer : B

46. Which is false statement about tempering? Tempering is done to
A. Improve machinability
B. Improve ductility
C. Improve toughness
D. Release stresses
Answer : A

47. The transistor is made of
A. Silver
B. Gold
C. Copper
D. Germanium
Answer : D

48. Pure iron is the structure of
A. Ferrite
B. Pearlite
C. Austenite
D. Ferrite and cementite
Answer : A

49. 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

50. Which of the following alloys does not have copper as one of the constituents?
A. Delta metal
B. Monel metal
C. Constantan
D. Nichrome
Answer : D