NDA - Engineering Materials 1000+ MCQ [Solved] PDF Download

1. 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

2. The machinability of steel is improved by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
Answer : D

3. 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

4. Tungsten when added to steel ________ the critical temperature.
A. Does not effect
B. Lowers
C. Raises
D. None of these
Answer : C

5. Hardness of upper bainite (acicular structure) is about
A. RC 65
B. RC 48
C. RC 57
D. RC 80
Answer : B

6. Acidic 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 : B

7. The correct sequence for descending order of machinability is
A. Grey cast iron, low carbon steel, wrought iron
B. Low carbon steel, grey cast iron, wrought iron
C. Wrought iron, low carbon steel, grey cast iron
D. Wrought iron, grey cast iron, low carbon steel
Answer : A

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

9. 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

10. 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

11. Which of the following iron exist between 910°C and 1403°C?
A. ?-iron
B. ?-iron
C. ?-iron
D. ?-iron
Answer : C

12. Delta iron occurs at temperature of
A. Room temperature
B. Above melting point
C. Between 1400°C and 1539°C
D. Between 910°C and 1400°C
Answer : C

13. The addition of which of the following improves machining of copper?
A. Sulphur
B. Vanadium
C. Tin
D. Zinc
Answer : A

14. 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

15. Isotropic materials are those which have the same
A. Elastic properties in all directions
B. Stresses induced in all directions
C. Thermal properties in all directions
D. Electric and magnetic properties in all directions
Answer : A

16. Constantan an alloy used in thermocouples is an alloy of
A. Copper and tin
B. Copper and zinc
C. Copper and iron
D. Copper and nickel
Answer : D

17. The alloying element which can replace tungsten in high speed steels is
A. Nickel
B. Vanadium
C. Cobalt
D. Molybdenum
Answer : D

18. Gamma iron exits at following temperature
A. Room temperature
B. Near melting point
C. Between 1400°C and 1539°C
D. Between 910°C and 1400°C
Answer : D

19. Which of the following impurity in cast iron promotes graphite nodule formation and increases the fluidity of the molten metal?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
Answer : A

20. 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

21. In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled
A. In still air
B. Slowly in the furnace
C. Suddenly in a suitable cooling medium
D. Any one of these
Answer : B

22. When low carbon steel is heated up to lower critical temperature
A. There is no change in grain size
B. The average grain size is a minimum
C. The grain size increases very rapidly
D. The grain size first increases and then decreases very rapidly
Answer : A

23. 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

24. Monel metal is an alloy of
A. Nickel and copper
B. Nickel and chromium
C. Nickel, Chromium and iron
D. Copper and chromium
Answer : A

25. The portion of the blast furnace below its widest cross-section is called
A. Hearth
B. Stack
C. Bosh
D. Throat
Answer : C

26. 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

27. Admiralty gun metal contains
A. 63 to 67% nickel and 30% copper
B. 88% copper, 10% tin and rest zinc
C. Alloy of tin, lead and cadmium
D. Iron scrap and zinc
Answer : B

28. Y-alloy contains
A. 3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
B. 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
C. 4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
D. 5 to 6% tin, 2 to 3% copper and rest aluminium
Answer : B

29. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
A. Increase
B. Decrease
C. Remain same
D. First increase and then decrease
Answer : A

30. Ferromagnetic alpha iron exists in temperature range of
A. Below 723°C
B. 770 to 910°C
C. 910 to 1440°C
D. 1400 to 1539°C
Answer : A

31. Bronze contains
A. 70% copper and 30% zinc
B. 90% copper and 10% tin
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 75% copper and rest tin
Answer : B

32. 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

33. The cupola is used to manufacture
A. Pig iron
B. Cast iron
C. Wrought iron
D. Steel
Answer : B

34. Normalising of steel is done to
A. Refine the grain structure
B. Remove strains caused by cold working
C. Remove dislocations caused in the internal structure due to hot working
D. All of the above
Answer : D

35. Corundum contains more than 95%
A. Steel
B. Al₂O₃
C. SiO₂
D. MgO
Answer : B

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

37. The unit cells
A. Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal
B. Have the same orientation and their similar faces are parallel
C. May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice
D. All of the above
Answer : D

38. 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

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

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 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

42. Which of the following statements are true for annealing of steels?
A. Steels are heated to 500 to 700°C
B. Cooling is done slowly and steadily
C. Internal stresses are relieved
D. All of these
Answer : D

43. The toughness of a material __________ when it is heated.
A. Remain same
B. Decreases
C. Increases
D. None of these
Answer : B

44. The crystal structure of brass is
A. F.C.C.
B. B.C.C.
C. H.C.P.
D. Orthorhombic crystalline structure
Answer : A

45. 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

46. In high speed steels, manganese is used to tougher the metal and to increase its
A. Yield point
B. Critical temperature
C. Melting point
D. Hardness
Answer : B

47. The hardness is the property of a material due to which it
A. Can be drawn into wires
B. Breaks with little permanent distortion
C. Can cut another metal
D. Can be rolled or hammered into thin sheets
Answer : C

48. A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as
A. Allotropic change
B. Recrystallisation
C. Heat treatment
D. Precipitation
Answer : A

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

50. If a refractory contains high content of silicon, it means refractory is
A. Acidic
B. Basic
C. Neutral
D. Brittle
Answer : C