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

1. Which is false statement about properties of aluminium?
A. Modulus of elasticity is fairly low
B. Wear resistance is very good
C. Fatigue strength is not high
D. Creep strength limits its use to fairly low temperatures
Answer : B

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

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

4. 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

5. 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

6. The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as
A. Hysteresis
B. Creep
C. Visco elasticity
D. Boeschinger effect
Answer : D

7. 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

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

9. 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

10. 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

11. The charge of the blast furnace consists of
A. Calcined ore (8 parts), coke (4 parts) and limestone (1 part)
B. Calcined ore (4 parts), coke (1 part) and limestone (8 parts)
C. Calcined ore (1 part), coke (8 parts) and limestone (4 parts)
D. Calcined ore, coke and limestone all in equal parts
Answer : A

12. 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

13. 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

14. 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

15. 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

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

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

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

19. German silver contains
A. 1% silver
B. 2.5% silver
C. 5% silver
D. 10% silver
Answer : C

20. When steel containing less than 0.8% carbon is cooled slowly from temperatures above or within the critical range, it consists of
A. Mainly ferrite
B. Mainly pearlite
C. Ferrite and pearlite
D. Pearlite and cementite
Answer : C

21. In which of the following cases, consideration of creep is important
A. Flywheel of steam engine
B. Cast iron pipes
C. Cycle chains
D. Gas turbine blades
Answer : D

22. 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

23. 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

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

25. Which of the following metal is used for nuclear energy?
A. Uranium
B. Thorium
C. Niobium
D. All of these
Answer : D

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

27. The blade of a power saw is made of
A. Boron steel
B. High speed steel
C. Stainless steel
D. Malleable cast iron
Answer : B

28. 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

29. 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

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

31. 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

32. 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

33. An alloy steel which is work hardenable and which is used to make the blades of bulldozers, bucket wheel excavators and other earth moving equipment contain iron, carbon and
A. Chromium
B. Silicon
C. Manganese
D. Magnesium
Answer : C

34. The property of a material due to which it breaks with little permanent distortion, is called
A. Brittleness
B. Ductility
C. Malleability
D. Plasticity
Answer : A

35. A material is known as allotropic or polymorphic if it
A. Has a fixed structure under all conditions
B. Exists in several crystal forms at different temperatures
C. Responds to heat treatment
D. Has its atoms distributed in a random pattern
Answer : B

36. Aluminium bronze contains
A. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B. 92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
C. 10% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper
Answer : C

37. Duralumin contains
A. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B. 92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg
C. 10% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper
Answer : A

38. Shock resistance of steel is increased by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
Answer : C

39. 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

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. Phosphor bronze contains
A. 0.5% of phosphorous
B. 1% phosphorous
C. 2.5% phosphorous
D. None of the above
Answer : D

42. When low carbon steel is heated up to upper 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 : B

43. 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

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

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

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

47. 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

48. The percentage of carbon in grey iron castings usually varies between
A. 0.5 to 1 %
B. 1.2 %
C. 2.5 to 4.5 %
D. 5 to 7 %
Answer : C

49. Which of the following is the binding material in cemented carbides?
A. Cobalt
B. Nickel
C. Vanadium
D. Iron
Answer : A

50. 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