Engineering Materials Practice Set-4

Page 1 of 4

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

RC 80

RC 65

RC 48

RC 57

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

Heat resisting steel

High speed steel

Stainless steel

Invar

3. Stress relaxation is the phenomenon

In which stress remains constant on increasing load

In which parts are not loaded

Stress reduces on increasing load

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

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

Precipitation

Allotropic change

Recrystallization

Heat treatment

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

20 : 80

50 : 50

40 : 60

60 : 40

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

Brittle fracture is always preceded by noise

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

High temperature and low strain rates favour brittle fracture

Cup and cone formation is characteristic for brittle materials

7. Delta-iron occurs between the temperature ranges of

900°C to 1400°C

400°C to 600°C

1400°C to 1530°C

600°C to 900°C

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

Tempering

Annealing

Carburising

Normalizing

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

Copper and nickel

Copper and tin

Copper and iron

Copper and zinc

10. Pig iron is the name given to

Product of blast furnace made by reduction of iron ore

Raw material for blast furnace

Iron in molten form in the ladles

Iron containing huge quantities of carbon

Page 2 of 4

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

Vanadium

Zinc

Sulphur

Tin

12. Dye penetrant method is generally used to locate

Core defects

Superficial defects

Surface defects

Temporary defects

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

Manganese

Phosphorus

Silicon

Sulphur

14. Maximum percentage of carbon in austenite is

0.8%

0.025%

0.26%

1.7%

15. Which of the following statement is correct?

The chilled cast iron has no graphite

The product produced by blast-furnace is called cast iron

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

The cast iron has high tensile strength

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

X-ray techniques

Metallurgical microscope

Naked eye

Optical microscope

17. 1841 high speed steel contains

None of the above

Vanadium 4%, chromium 18% and tungsten 1%

Vanadium 18%, chromium 1% and tungsten 4%

Vanadium 1%, chromium 4% and tungsten 18%

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

Plasticity

Hardness

Ductility

Brittleness

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

The points where there is no further flow of metal

The points where no further change occurs

The points of discontinuity

Constant for all metals

20. Recrystallization temperature can be lowered by

Purification of metal

Working at lower temperature

Grain refinement

All of the above

Page 3 of 4

21. Ferromagnetic alpha iron exists in temperature range of

Below 723°C

910 to 1440°C

770 to 910°C

1400 to 1539°C

22. Inconel contains

65% nickel, 15% chromium and 20% iron

80% nickel and 20% chromium

80% nickel, 14% chromium and 6% iron

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

23. Vanadium in high speed steels

Promotes retention of austenite

Promotes decarburisation

Forms very hard carbides and thus increases wear resistance

Provides high hot hardness

24. Connecting rod is, usually, made from

Low carbon steel

Medium carbon steel

High speed steel

High carbon steel

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

Silicon

Sulphur

Manganese

Phosphorus

26. Silicon when added to copper improves

Machinability

Hardness

Strength and ductility

Hardness and strength

27. Age-hardening is related with

Stainless steel

Duralumin

German silver

Gun metal

28. Nodular iron has

High machinability

All of the above

High tensile strength

Low melting point

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

Phosphorus

Manganese

Sulphur

Silicon

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

Around 0°C

Above 100°K

Below 10°K

Around 100°C

Page 4 of 4

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

Wrought iron

Mild steel

Cast iron

Brass

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

Amorphous material

Crystalline material

None of these

Mesomorphous material

33. Babbitt metal is a

Tin base alloy

Copper base alloy

Cadmium base alloy

Lead base alloy

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

Cycle chains

Flywheel of steam engine

Gas turbine blades

Cast iron pipes

35. Wrought iron

Is a ductile material

Can be easily forged or welded

All of these

Cannot stand sudden and excessive shocks

36. The metallic structure of mild steel is

Cubic structure

Body centered cubic

Hexagonal close packed

Face centered cubic

37. White cast iron contains carbon in the form of

Graphite

Free carbon

Cementite

White carbon

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

Toughness

Creep

Fatigue strength

Resilience

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

Different crystal structures at different temperatures

Atoms distributed in random pattern

Any one of the above

Fixed structure at all temperatures

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

Decrease

Remain same

Increase

First increase and then decrease

Engineering Materials Practice Set-4

Related

Leave a ReplyCancel reply

Secured Payments

Protection

Engineering Materials Practice Set-4

Share this Now with Friends:

Related

Leave a ReplyCancel reply

Secured Payments

Protection