1000+ Engineering Materials MCQ for SSC Stenographer [Solved]

1. Delta-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 : D

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

3. Dislocations in materials refer to the following type of defect
A. Point defect
B. Line defect
C. Plane defect
D. Volumetric defect
Answer : B

4. Specify the sequence correctly
A. Grain growth, recrystallisation, stress relief
B. Stress relief, grain growth, recrystallisation
C. Stress relief, recrystallisation, grain growth
D. Grain growth, stress relief, recrystallisation
Answer : C

5. Which is false statement about case hardening? Case hardening is done by
A. Electroplating
B. Cyaniding
C. Induction hardening
D. Nitriding
Answer : A

6. Cementite consist of
A. 13% carbon and 87% ferrite
B. 13% cementite and 87% ferrite
C. 13% ferrite and 87% cementite
D. 6.67% carbon and 93.33% iron
Answer : D

7. Which of the following is an amorphous material?
A. Mica
B. Silver
C. Lead
D. Glass
Answer : D

8. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
A. 770°C
B. 910°C
C. 1050°C
D. Below recrystallisation temperature
Answer : A

9. A reversible change in the atomic structure of steel with corresponding change in the properties is known as
A. Molecular change
B. Physical change
C. Allotropic change
D. Solidus change
Answer : C

10. Wrought iron
A. Is a ductile material
B. Can be easily forged or welded
C. Cannot stand sudden and excessive shocks
D. All of these
Answer : D

11. Basic constituents of Monel metal are
A. Nickel, copper
B. Nickel, molybdenum
C. Zinc, tin, lead
D. Nickel, lead and tin
Answer : A

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

13. 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

14. Which of the following metal shrinks most from molten state to solid state?
A. Cast iron
B. Cast steel
C. Brass
D. Admiralty metal
Answer : D

15. In compression, a prism of brittle material will break
A. By forming a bulge
B. By shearing along oblique plane
C. In direction perpendicular to application of load
D. By crushing into thousands of pieces
Answer : B

16. 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

17. White 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 : B

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

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

20. The carbon in the pig iron varies from
A. 0.1 to 0.5 %
B. 0.5 to 1 %
C. 1 to 5 %
D. 5 to 10 %
Answer : C

21. The usual composition of a soldering alloy is
A. Tin, lead and small percentage of antimony
B. Tin and lead
C. Tin, lead and silver
D. Tin and copper
Answer : A

22. 1841 high speed steel contains
A. Vanadium 4%, chromium 18% and tungsten 1%
B. Vanadium 1%, chromium 4% and tungsten 18%
C. Vanadium 18%, chromium 1% and tungsten 4%
D. None of the above
Answer : B

23. The brown smoke during the operation of a Bessemer converter indicates that the
A. Air is burning out silicon and manganese
B. Silicon and manganese has burnt and carbon has started oxidising
C. The converter must be titled to remove the contents of the converter
D. The brown smoke does not occur during the operation of a Bessemer converter
Answer : A

24. The compressive strength of cast iron is ________ that of its tensile strength.
A. Equal to
B. Less than
C. More than
D. None of these
Answer : C

25. Maximum percentage of carbon in austenite is
A. 0.025 %
B. 0.26 %
C. 0.8 %
D. 1.7 %
Answer : D

26. Manganese in steel increases its
A. Tensile strength
B. Hardness
C. Ductility
D. Fluidity
Answer : A

27. Addition of lead and bismuth 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 : D

28. The steel widely used for motor car crankshafts is
A. Nickel steel
B. Chrome steel
C. Nickel-chrome steel
D. Silicon steel
Answer : B

29. White 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. Silver and chromium
Answer : C

30. Induction hardening is basically a
A. Carburising process
B. Surface hardening process
C. Core hardening process
D. None of these
Answer : B

31. Addition of silicon 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 : A

32. Materials after cold working are subjected to following process to relieve stresses
A. Hot working
B. Tempering
C. Normalising
D. Annealing
Answer : D

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

34. 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

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

36. Blast furnace produces following by reduction of iron ore
A. Cast iron
B. Pig iron
C. Wrought iron
D. Malleable iron
Answer : B

37. The ultimate tensile strength of low carbon steel by working at a high strain rate will
A. Decrease
B. Increase
C. Remain constant
D. First increase and then decrease
Answer : B

38. Sulphur in cast iron
A. Makes the iron soft and easily machinable
B. Increases hardness and brittleness
C. Make the iron white and hard
D. Aids fusibility and fluidity
Answer : B

39. 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

40. The lower critical point for all steels is
A. 600°C
B. 700°C
C. 723°C
D. 913°C
Answer : C

41. 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

42. 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

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

44. 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

45. Preheating is essential in welding
A. Cast iron
B. High speed steel
C. All nonferrous materials
D. All of the above
Answer : A

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

47. Austenite is a combination of
A. Ferrite and cementite
B. Cementite and gamma iron
C. Ferrite and austenite
D. Ferrite and iron graphite
Answer : B

48. 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

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

50. The hardness and tensile strength in austenitic stainless steel can be increased by
A. Hardening and cold working
B. Normalising
C. Martempering
D. Full annealing
Answer : A