Engineering Materials Practice Set-2

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1. The correct sequence for descending order of machinability is

Low carbon steel, grey cast iron, wrought iron

Wrought iron, grey cast iron, low carbon steel

Wrought iron, low carbon steel, grey cast iron

Grey cast iron, low carbon steel, wrought iron

2. Monel metal contains

Alloy of tin, lead and cadmium

88% copper and 10% tin and rest zinc

Malleable iron and zinc

63 to 67% nickel and 30% copper

3. Sulphur in steel

Reduces the grain size

Decreases tensile strength and hardness

Lowers the toughness and transverse ductility

Acts as deoxidiser

4. Addition of manganese to aluminium results in

One of the best known age and precipitation hardening systems

Improvement of corrosion resistance

Improving machinability

Improvement of casting characteristics

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

Chromium

Silicon

Manganese

Carbon

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

Allotropic change

Physical change

Solidus change

Molecular change

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

910°C

Below recrystallization temperature

770°C

1050°C

8. Grey cast iron

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

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

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

70 : 30

50 : 50

40 : 60

30 : 70

10. The presence of hydrogen in steel causes

Corrosion resistance

Embrittlement

Reduced neutron absorption cross-section

Improved Weldability

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

White metal

Fusible metal

Phosphor bronze

Solder admiralty

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

Remain same

Increases

Decreases

None of these

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

Austenitic stainless steel

Nickel steel

Ferritic stainless steel

Martenistic stainless steel

14. Aluminium bronze contains

10% aluminium and 90% copper

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

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

90% magnesium and 9% aluminium with some copper

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

High ductility

Uniform strength in all directions

High resistance to rusting and corrosion

Ability of hold protective coating

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

Sulphur

Carbon

Silicon

Manganese

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

Harden steel slightly

Improve machining characteristic

Relieve stresses

Soften material

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

Coordination number

Atomic packing factor

Space lattice

None of these

19. Pearlite consists of

6.67% carbon and 93.33% iron

13% carbon and 87% ferrite

13% cementite and 87% ferrite

13% ferrite and 87% cementite

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

1500°C to 1700°C

800°C to 1000°C

400° to 700°C

1200°C to 1300°C

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21. Admiralty gun metal contains

63 to 67% nickel and 30% copper

Alloy of tin, lead and cadmium

Iron scrap and zinc

88% copper, 10% tin and rest zinc

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

γ-iron

β-iron

δ-iron

α-iron

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

There is no change in grain size

The grain size increases very rapidly

The average grain size is a minimum

The grain size first increases and then decreases very rapidly

24. Malleable cast iron

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

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

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

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

None of these

Covalent bond

Ionic bond

Metallic bond

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

Equal to

Less than

More than

None of these

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

Point defect

Volumetric defect

Line defect

Plane defect

28. An eutectoid steel consists of

Wholly pearlite

Pearlite and ferrite

Pearlite and cementite

Wholly austenite

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

Naked eye

Optical microscope

X-ray techniques

Metallurgical microscope

30. Ductile cast iron

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 creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material

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

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31. The percentage of carbon in pig iron varies from

2.5 to 4%

1.5 to 2.5%

0.1 to 1.2%

4 to 4.5%

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

Hindalium

Y-alloy

Magnalium

Duralumin

33. 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

34. 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)

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

Silicon

Sulphur

Manganese

Phosphorus

36. Duralumin contains

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

5 to 6% tin, 2 to 3% 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

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

Mesomorphous material

Amorphous material

None of these

Crystalline material

38. Structural steel contains following principal alloying elements

Zinc, sulphur, and chromium

Nickel, chromium and manganese

Tungsten, molybdenum and phosphorous

Lead, tin, aluminium

39. White 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

40. Free cutting steels

Is used where rapid machining is the prime requirement

Contain carbon in free from

Require minimum cutting force

Can be cut freely

Engineering Materials Practice Set-2

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