Engineering Materials Practice Set-4

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1. Super conduction by metals is observed in the temperature range of

Above 100°K

Around 0°C

Around 100°C

Below 10°K

2. The metallic structure of mild steel is

Cubic structure

Body centered cubic

Hexagonal close packed

Face centered cubic

3. Hardness of lower bainite (tempered martensite) is about

RC 48

RC 57

RC 80

RC 65

4. Ferromagnetic alpha iron exists in temperature range of

1400 to 1539°C

770 to 910°C

Below 723°C

910 to 1440°C

5. The ability of a material to absorb energy in the plastic range is called

Toughness

Fatigue strength

Creep

Resilience

6. Macrostructure of a material is, generally, examined by

Metallurgical microscope

Naked eye

X-ray techniques

Optical microscope

7. Nodular iron has

Low melting point

All of the above

High tensile strength

High machinability

8. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will

Decrease

Increase

First increase and then decrease

Remain same

9. Which of the following pipes is least corrosion resistant?

Cast iron

Mild steel

Brass

Wrought iron

10. Which of the following impurity in cast iron promotes graphite nodule formation and increases the fluidity of the molten metal?

Sulphur

Silicon

Phosphorus

Manganese

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11. In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.

Phosphorus

Sulphur

Silicon

Manganese

12. Pig iron is the name given to

Raw material for blast furnace

Iron containing huge quantities of carbon

Iron in molten form in the ladles

Product of blast furnace made by reduction of iron ore

13. Babbitt metal is a

Lead base alloy

Cadmium base alloy

Tin base alloy

Copper base alloy

14. Which of the following statement is true about brittle fracture?

High temperature and low strain rates favour brittle fracture

Cup and cone formation is characteristic for brittle materials

Many metals with hexagonal close packed (H.C.P) crystal structure commonly show brittle fracture

Brittle fracture is always preceded by noise

15. The heat treatment process used for softening hardened steel is

Normalizing

Carburising

Annealing

Tempering

16. The addition of which of the following improves machining of copper?

Zinc

Vanadium

Tin

Sulphur

17. Constantan an alloy used in thermocouples is an alloy of

Copper and nickel

Copper and tin

Copper and iron

Copper and zinc

18. In which of the following cases, consideration of creep is important

Flywheel of steam engine

Gas turbine blades

Cycle chains

Cast iron pipes

19. White cast iron contains carbon in the form of

Graphite

White carbon

Cementite

Free carbon

20. Connecting rod is, usually, made from

Medium carbon steel

High carbon steel

High speed steel

Low carbon steel

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21. Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?

Manganese

Silicon

Phosphorus

Sulphur

22. Stress relaxation is the phenomenon

In which deformation tends to loosen the joint and produces a stress reduced

In which stress remains constant on increasing load

In which parts are not loaded

Stress reduces on increasing load

23. Wrought iron

All of these

Can be easily forged or welded

Cannot stand sudden and excessive shocks

Is a ductile material

24. An important property of high silicon (12-18%) cast iron is the high

Ductility

Plasticity

Hardness

Brittleness

25. 1841 high speed steel contains

None of the above

Vanadium 1%, chromium 4% and tungsten 18%

Vanadium 4%, chromium 18% and tungsten 1%

Vanadium 18%, chromium 1% and tungsten 4%

26. Silicon when added to copper improves

Machinability

Hardness

Strength and ductility

Hardness and strength

27. The material in which the atoms are arranged regularly in some directions but not in others, is called

Mesomorphous material

None of these

Amorphous material

Crystalline material

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

Recrystallization

Heat treatment

Allotropic change

Precipitation

29. Recrystallization temperature can be lowered by

All of the above

Purification of metal

Grain refinement

Working at lower temperature

30. Which of the following statement is correct?

The chilled cast iron has no graphite

The cast iron has high tensile strength

The pig iron is the name given to the product produced by cupola

The product produced by blast-furnace is called cast iron

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31. For the allotropic forms of iron, the points of arrest are

The points of discontinuity

The points where there is no further flow of metal

The points where no further change occurs

Constant for all metals

32. Maximum percentage of carbon in austenite is

1.7%

0.025%

0.26%

0.8%

33. Inconel contains

80% nickel, 14% chromium and 6% iron

80% nickel and 20% chromium

68% nickel, 29% copper and 3% other constituents

65% nickel, 15% chromium and 20% iron

34. Which of the following material has nearly zero coefficient of expansion?

Stainless steel

Invar

Heat resisting steel

High speed steel

35. A material is said to be allotropic, if it has

Atoms distributed in random pattern

Any one of the above

Different crystal structures at different temperatures

Fixed structure at all temperatures

36. Muntz metal contains copper and zinc in the ratio of

50 : 50

60 : 40

20 : 80

40 : 60

37. Delta-iron occurs between the temperature ranges of

600°C to 900°C

900°C to 1400°C

400°C to 600°C

1400°C to 1530°C

38. Vanadium in high speed steels

Forms very hard carbides and thus increases wear resistance

Provides high hot hardness

Promotes retention of austenite

Promotes decarburisation

39. Age-hardening is related with

Stainless steel

Duralumin

Gun metal

German silver

40. Dye penetrant method is generally used to locate

Superficial defects

Surface defects

Core defects

Temporary defects

Engineering Materials Practice Set-4

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