Engineering Materials Practice Set-2

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

Metallurgical microscope

Optical microscope

X-ray techniques

Naked eye

2. Addition of manganese to aluminium results in

One of the best known age and precipitation hardening systems

Improving machinability

Improvement of corrosion resistance

Improvement of casting characteristics

3. The presence of hydrogen in steel causes

Reduced neutron absorption cross-section

Improved Weldability

Embrittlement

Corrosion resistance

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

Uniform strength in all directions

Ability of hold protective coating

High ductility

High resistance to rusting and corrosion

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

Point defect

Line defect

Plane defect

Volumetric defect

6. Duralumin contains

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

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

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

β-iron

γ-iron

α-iron

δ-iron

8. Aluminium bronze contains

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

90% magnesium and 9% aluminium with some copper

10% aluminium and 90% copper

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

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

Sulphur

Manganese

Silicon

Phosphorus

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

Y-alloy

Duralumin

Magnalium

Hindalium

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

None of these

Equal to

Less than

More than

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

None of these

Crystalline material

Mesomorphous material

Amorphous material

13. Monel metal contains

63 to 67% nickel and 30% copper

Alloy of tin, lead and cadmium

88% copper and 10% tin and rest zinc

Malleable iron and zinc

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

Remain same

Increases

Decreases

None of these

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

None of these

Space lattice

Atomic packing factor

Coordination number

16. Grey cast iron

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

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

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 o magnesium (or cerium) in the ladle Graphite is in nodular or spheroidal form and is well dispersed throughout the material

17. Ductile 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

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 and is obtained by cooling rapidly. It is almost unmachinable

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

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

50 : 50

70 : 30

40 : 60

30 : 70

19. An eutectoid steel consists of

Wholly austenite

Wholly pearlite

Pearlite and ferrite

Pearlite and cementite

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

Carbon

Manganese

Silicon

Chromium

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21. Free cutting steels

Contain carbon in free from

Can be cut freely

Require minimum cutting force

Is used where rapid machining is the prime requirement

22. Admiralty gun metal contains

Iron scrap and zinc

88% copper, 10% tin and rest zinc

Alloy of tin, lead and cadmium

63 to 67% nickel and 30% copper

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

1050°C

Below recrystallization temperature

770°C

910°C

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

Solidus change

Allotropic change

Physical change

Molecular change

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

1500°C to 1700°C

400° to 700°C

800°C to 1000°C

1200°C to 1300°C

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

Covalent bond

Metallic bond

Ionic bond

None of these

27. Malleable cast iron

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

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

28. The percentage of carbon in pig iron varies from

1.5 to 2.5%

2.5 to 4%

4 to 4.5%

0.1 to 1.2%

29. The correct sequence for descending order of machinability is

Wrought iron, low carbon steel, grey cast iron

Low carbon steel, grey cast iron, wrought iron

Wrought iron, grey cast iron, low carbon steel

Grey cast iron, low carbon steel, wrought iron

30. Structural steel contains following principal alloying elements

Zinc, sulphur, and chromium

Tungsten, molybdenum and phosphorous

Lead, tin, aluminium

Nickel, chromium and manganese

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

Relieve stresses

Harden steel slightly

Improve machining characteristic

Soften material

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

Manganese

Silicon

Carbon

Sulphur

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

Solder admiralty

Fusible metal

White metal

Phosphor bronze

34. Pearlite consists of

13% carbon and 87% ferrite

13% cementite and 87% ferrite

6.67% carbon and 93.33% iron

13% ferrite and 87% cementite

35. 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

There is no change in grain size

The average grain size is a minimum

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

(B) A mixture of tar and burnt dolomite bricks

(C) Both (A) and (B)

(D) None of these

(A) Silica bricks

37. When medium carbon steel is heated to coarsening 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

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

Austenitic stainless steel

Ferritic stainless steel

Martenistic stainless steel

Nickel steel

39. White 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

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

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

40. Sulphur in steel

Acts as deoxidiser

Reduces the grain size

Lowers the toughness and transverse ductility

Decreases tensile strength and hardness

Engineering Materials Practice Set-2

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