1000+ Engineering Materials MCQ for SBI PO [Solved]

1. 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

2. 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

3. 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

4. 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

5. The machinability of aluminium increases when __________ is added to aluminium.
A. Copper
B. Magnesium
C. Silicon
D. Lead and bismuth
Answer : D

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

7. Tungsten in high speed steel provides
A. Hot hardness
B. Toughness
C. Wear resistance
D. Sharp cutting edge
Answer : A

8. 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

9. The purpose of heat treatment is to
A. Relieve the stresses set up in the material after hot or cold working
B. Modify the structure of the material
C. Change grain size
D. Any one of these
Answer : D

10. Compressive strength of grey cast iron in tonnes/cm is of the order of
A. 35
B. 57
C. 710
D. 1015
Answer : B

11. 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

12. 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

13. The metallic structure of mild steel is
A. Body centred cubic
B. Face centred cubic
C. Hexagonal close packed
D. Cubic structure
Answer : A

14. Steel containing ferrite and pearlite is
A. Hard
B. Soft
C. Tough
D. Hard and tough
Answer : B

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

16. 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

17. Cast iron has
A. High tensile strength
B. Its elastic limit close to the ultimate breaking strength
C. High ductility
D. All of the above
Answer : B

18. The percentage of carbon in cast iron varies from
A. 0.1 to 0.5
B. 0.5 to 1
C. 1 to 1.7
D. 1.7 to 4.5
Answer : D

19. Cold rolled steel sheets contain carbon of the following order
A. 0.1 %
B. 0.2 %
C. 0.4 %
D. 0.6 %
Answer : A

20. Cemented carbide tools are not found to be suitable for cutting
A. Brass
B. Cast iron
C. Aluminium
D. Steel
Answer : D

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

22. 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

23. 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

24. The percentage carbon content in wrought iron is about
A. 0.02
B. 0.1
C. 02
D. 0.4
Answer : A

25. Quenching is not necessary when hardening is done by
A. Case hardening
B. Flame hardening
C. Nitriding
D. Any one of these
Answer : C

26. 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

27. 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

28. 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

29. Addition of manganese 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 : B

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

31. 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

32. 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

33. Perminvar alloy having constant permeability is an alloy of
A. Nickel, copper and iron
B. Nickel, copper and zinc
C. Copper, nickel and antimony
D. Iron, zinc and bismuth
Answer : A

34. 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

35. The maximum internal diameter of a blast furnace is about
A. 3 m
B. 6 m
C. 9 m
D. 12 m
Answer : C

36. The property of a material essential for spring materials is
A. Stiffness
B. Ductility
C. Resilience
D. Plasticity
Answer : C

37. The ability of a material to resist softening at high temperature is known as
A. Creep
B. Hot tempering
C. Hot hardness
D. Fatigue
Answer : C

38. 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

39. The elastic stress strain behaviour of rubber is
A. Linear
B. Nonlinear
C. Plastic
D. No fixed relationship
Answer : B

40. 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

41. Railway rails are normally made of
A. Mild steel
B. Alloy steel
C. High carbon
D. Tungsten steel
Answer : C

42. Aluminium bronze contains aluminium and copper in the ratio of
A. 50 : 50
B. 40 : 60
C. 60 : 40
D. 10 : 90
Answer : D

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

44. The presence of sulphur in pig iron makes
A. It easily machinable
B. It brittle
C. It hard
D. The casting unsound
Answer : D

45. 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

46. 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

47. The lower critical temperature
A. Decreases as the carbon content in steel increases
B. Increases as the carbon content in steel increases
C. Is same for all steels
D. Depends upon the rate of heating
Answer : C

48. 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

49. 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

50. 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