Engineering Materials Practice Set-2

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1. Crystal structure of a material is, generally, examined by

Optical microscope

X-ray techniques

Naked eye

Metallurgical microscope

2. The percentage of carbon in pig iron varies from

4 to 4.5%

1.5 to 2.5%

2.5 to 4%

0.1 to 1.2%

3. Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio

50 : 50

70 : 30

40 : 60

30 : 70

4. The compressive strength of cast iron is __________that of its tensile strength.

None of these

Equal to

More than

Less than

5. Malleable cast iron

Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

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

Is produced by annealing process. It is soft, tough, and easily machined metal

Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

6. A reversible change in the atomic structure of steel with corresponding change in the properties is known as

Physical change

Molecular change

Allotropic change

Solidus change

7. Which of the following element results in presence of free graphite in C.I.?

Sulphur

Silicon

Carbon

Manganese

8. Which of the following is added in low carbon steels to prevent them from becoming porous?

Sulphur

Phosphorus

Manganese

Silicon

9. Duralumin contains

5 to 6% tin, 2 to 3% copper and rest aluminium

4 to 4.5% magnesium, 3 to 4% copper and rest aluminium

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

3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium

10. Ductile cast iron

Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

Is produced by annealing process. It is soft, tough and easily machined metal

Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

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

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11. Which of the following alloys does not contain tin?

White metal

Fusible metal

Phosphor bronze

Solder admiralty

12. Free cutting steels

Can be cut freely

Is used where rapid machining is the prime requirement

Contain carbon in free from

Require minimum cutting force

13. When low carbon steel is heated up to upper critical temperature

The grain size first increases and then decreases very rapidly

The grain size increases very rapidly

The average grain size is a minimum

There is no change in grain size

14. In the lower part of the blast furnace (zone of fusion), the temperature is

400° to 700°C

1500°C to 1700°C

1200°C to 1300°C

800°C to 1000°C

15. Dislocations in materials refer to the following type of defect

Plane defect

Point defect

Line defect

Volumetric defect

16. Structural steel contains following principal alloying elements

Nickel, chromium and manganese

Lead, tin, aluminium

Zinc, sulphur, and chromium

Tungsten, molybdenum and phosphorous

17. White cast iron

Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

Is produced by annealing process. It is soft, tough and easily machined metal

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

Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

18. Which of the following iron exist between 910°C and 1403°C?

β-iron

γ-iron

α-iron

δ-iron

19. Sulphur in steel

Reduces the grain size

Decreases tensile strength and hardness

Lowers the toughness and transverse ductility

Acts as deoxidiser

20. An eutectoid steel consists of

Wholly pearlite

Pearlite and cementite

Wholly austenite

Pearlite and ferrite

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21. Aluminium bronze contains

90% magnesium and 9% aluminium with some copper

94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe

92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg

10% aluminium and 90% copper

22. Addition of manganese to aluminium results in

Improvement of corrosion resistance

Improvement of casting characteristics

One of the best known age and precipitation hardening systems

Improving machinability

23. Pearlite consists of

13% carbon and 87% ferrite

13% ferrite and 87% cementite

6.67% carbon and 93.33% iron

13% cementite and 87% ferrite

24. Which is false statement about annealing? Annealing is done to

Improve machining characteristic

Soften material

Relieve stresses

Harden steel slightly

25. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is

770°C

Below recrystallization temperature

1050°C

910°C

26. The ratio of the volume occupied by the atoms to the total volume of the unit cell is called

Atomic packing factor

Coordination number

None of these

Space lattice

27. When medium carbon steel is heated to coarsening temperature

The grain size first increases and then decreases very rapidly

The average grain size is a minimum

The grain size increases very rapidly

There is no change in grain size

28. The material in which the atoms are arranged chaotically, is called

None of these

Crystalline material

Mesomorphous material

Amorphous material

29. In basic Bessemer process, the furnace is lined with

(D) None of these

(A) Silica bricks

(B) A mixture of tar and burnt dolomite bricks

(C) Both (A) and (B)

30. The toughness of a material __________ when it is heated.

Increases

Remain same

None of these

Decreases

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31. Admiralty gun metal contains

Iron scrap and zinc

63 to 67% nickel and 30% copper

Alloy of tin, lead and cadmium

88% copper, 10% tin and rest zinc

32. The presence of hydrogen in steel causes

Reduced neutron absorption cross-section

Embrittlement

Improved Weldability

Corrosion resistance

33. The aluminium alloy, mainly used, for anodized utensil manufacture, is

Magnalium

Hindalium

Y-alloy

Duralumin

34. The bond formed by transferring electrons from one atom to another is called

None of these

Ionic bond

Covalent bond

Metallic bond

35. The alloy, mainly used for corrosion resistance in stainless steels is

Carbon

Manganese

Silicon

Chromium

36. A steel containing 16 to 18% chromium and about 0.12% carbon is called

Martenistic stainless steel

Ferritic stainless steel

Austenitic stainless steel

Nickel steel

37. Monel metal contains

88% copper and 10% tin and rest zinc

Malleable iron and zinc

Alloy of tin, lead and cadmium

63 to 67% nickel and 30% copper

38. Grey cast iron

Is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroidal form and is well dispersed throughout the material

Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

Is also known as chilled cast iron is obtained by cooling rapidly. It is almost unmachinable

Is produced by annealing process. I is soft, tough and easily machined metal

39. Which is the false statement about wrought iron? It has

High resistance to rusting and corrosion

Uniform strength in all directions

High ductility

Ability of hold protective coating

40. The correct sequence for descending order of machinability is

Wrought iron, grey cast iron, low carbon steel

Grey cast iron, low carbon steel, wrought iron

Low carbon steel, grey cast iron, wrought iron

Wrought iron, low carbon steel, grey cast iron

Engineering Materials Practice Set-2

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