1000+ Engineering Materials Multiple Choice Question Answer [Solved]

1. In spheroidising process, the steel is
A. Heated below the lower critical temperature and then cooled slowly
B. Heated up to the lower critical temperature and then cooled in still air
C. Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
D. None of the above
Answer : C

2. 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

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

4. 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

5. Which of the following material has nearly zero coefficient of expansion?
A. Stainless steel
B. High speed steel
C. Invar
D. Heat resisting steel
Answer : C

6. Chilled cast iron has
A. No graphite
B. A very high percentage of graphite
C. A low percentage of graphite
D. Graphite as its basic constituent of composition
Answer : A

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. Which of the following statement is true about brittle fracture?
A. High temperature and low strain rates favour brittle fracture
B. Many metals with hexagonal close packed (H.C.P) crystal structure commonly show brittle fracture
C. Brittle fracture is always preceded by noise
D. Cup and cone formation is characteristic for brittle materials
Answer : B

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

10. Depth of hardness of steel is increased by addition of
A. Nickel
B. Chromium
C. Tungsten
D. Vanadium
Answer : B

11. The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
A. Chromium
B. Nickel
C. Vanadium
D. Cobalt
Answer : D

12. 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

13. Argentite is the principal ore or raw material for
A. Aluminium
B. Tin
C. Zinc
D. Silver
Answer : D

14. 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

15. 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

16. 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

17. Basic solution is one which has pH value
A. Greater than 7
B. Equal to 7
C. Less than 7
D. pH value has nothing to do with basic solution
Answer : A

18. Closed packed hexagonal 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 : A

19. Amorphous material is one
A. In which atoms align themselves in a geometric pattern upon solidification
B. In which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid
C. Which is not attacked by phosphorous
D. Which emits fumes on melting
Answer : B

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

21. 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

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

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

24. The basic constituents of Hastelloy are
A. Aluminium, copper etc.
B. Nickel, molybdenum etc.
C. Nickel, Copper, etc.
D. All of the above
Answer : B

25. The percentage of carbon in low carbon steel is
A. 0.05 %
B. 0.15 %
C. 0.3 %
D. 0.5 %
Answer : B

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

27. For a steel containing 0.8% carbon
A. There is no critical point
B. There is only one critical point
C. There are two critical points
D. There can be any number of critical points
Answer : B

28. Steel with ________ carbon is known as hypo-eutectoid steel.
A. 0.8 %
B. Below 0.8 %
C. Above 0.8 %
D. None of these
Answer : B

29. The molecules in a solid move
A. In a random manner
B. In a haphazard way
C. In circular motion
D. Back and forth like tiny pendulums
Answer : D

30. Which of the following statement is correct?
A. The product produced by blast-furnace is called cast iron
B. The pig iron is the name given to the product produced by cupola
C. The cast iron has high tensile strength
D. The chilled cast iron has no graphite
Answer : D

31. 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

32. 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

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

34. 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

35. A small percentage of boron is added to steel in order to
A. Increase hardenability
B. Reduce machinability
C. Increase wear resistance
D. Increase endurance strength
Answer : A

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

37. 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

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

40. Which of the following impurity in cast iron makes it hard and brittle?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
Answer : B

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

42. The hardness of steel depends upon the
A. Amount of cementite it contains
B. Amount of carbon it contains
C. Contents of alloying elements
D. Method of manufacture of steel
Answer : A

43. The most effective inhibitor of grain growth, when added in small quantities is
A. Carbon
B. Vanadium
C. Manganese
D. Cobalt
Answer : B

44. The hardness of steel primarily depends on
A. Percentage of carbon
B. Percentage of alloying elements
C. Heat treatment employed
D. Shape of carbides and their distribution in iron
Answer : D

45. A cold chisel is made of
A. Mild steel
B. Cast iron
C. HSS
D. High carbon
Answer : D

46. Pearlite consists 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 : B

47. Lead is poured into the joint between two pipes. These pipes may be made of
A. Cast iron
B. Vitrified clay
C. Asbestos cement
D. Concrete
Answer : A

48. German silver contains
A. 1% silver
B. 2% silver
C. 5% silver
D. No silver
Answer : D

49. 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

50. 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