Engineering Materials Practice Set-3

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1. The metal suitable for bearings subjected to heavy loads, is

Monel metal

White metal

Silicon bronze

Phosphor bronze

2. The main alloying elements high speed steel in order of increasing proportion are

Vanadium, chromium, tungsten

Chromium, titanium, vanadium

Tungsten, titanium, vanadium

Tungsten, chromium, titanium

3. The property of a material which enables it to retain the deformation permanently, is called

Brittleness

Ductility

Plasticity

Malleability

4. The ability of a material to resist fracture due to high impact loads, is called

Toughness

Brittleness

Stiffness

Strength

5. The percentage of carbon in grey iron castings usually varies between

0.5 to 1%

5 to 7%

1.2%

2.5 to 4.5%

6. According to Indian standard specifications, plain carbon steel designated by 40 C8 means that the carbon content is

0.35 to 0.45%

0.04%

0.6 to 0.8%

0.4 to 0.6%

7. Cementite consist of

13% carbon and 87% ferrite

13% cementite and 87% ferrite

13% ferrite and 87% cementite

6.67% carbon and 93.33% iron

8. Which of the following property is desirable in parts subjected to shock and impact loads?

Brittleness

Toughness

Strength

Stiffness

9. Ductility of a material can be defined as

Ability to undergo large permanent deformations in tension

All of the above

Ability to recover its original form

Ability to undergo large permanent deformations in compression

10. Points of arrest for iron correspond to

Stages at which properties do not change with increase in temperature

Stages at which allotropic forms change

Stages at which further heating does not increase temperature for some time

There is nothing like points of arrest

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11. Corundum contains more than 95%

Steel

MgO

SiO₂

Al₂O₃

12. The defect which takes place due to imperfect packing of atoms during crystallization is known as

Point defect

None of these

Line defect

Surface defect

13. Tungsten in steel

Improves wear resistance, cutting ability and toughness

Improves cutting ability and reduces hardenability

Gives ductility, toughness, tensile strength and anti-corrosion properties

Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties

14. The tensile strength of wrought iron is maximum

Uniform in all directions

None of the above

Perpendicular to lines of slag distribution

Along the lines of slag distribution

15. The portion of the blast furnace below its widest cross-section is called

Throat

Bosh

Stack

Hearth

16. The machinability of steel is improved by adding

Sulphur, lead and phosphorus

Nickel

Chromium

Nickel and chromium

17. Hematite iron ore contains iron about

55%

70%

45%

30%

18. The usual composition of a soldering alloy is

Tin and lead

Tin, lead and silver

Tin, lead and small percentage of antimony

Tin and copper

19. In compression, a prism of brittle material will break

By crushing into thousands of pieces

By forming a bulge

By shearing along oblique plane

In direction perpendicular to application of load

20. The surface hardness of the following order is achieved by nitriding operation

600 VPN

1500 VPN

250 VPN

1000 to 1100 VPN

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21. The coke in the charge of blast furnace

Controls the grade of pig iron

Acts as an iron bearing mineral

Supplies heat to reduce ore and melt the iron

Forms a slag by combining with impurities

22. Which of the following elements does not impart hardness to steel?

Chromium

Nickel

Copper

Silicon

23. Large forgings, crank shafts, axles normally contain carbon up to

0.20 to 0.45%

0.55 to 1.0%

0.05 to 0.20%

0.45 to 0.55%

24. If a refractory contains high content of silicon, it means refractory is

Brittle

Neutral

Acidic

Basic

25. Which of the following represents the allotropic forms of iron?

Alpha iron, beta iron and gamma iron

Alpha iron and beta iron

Alpha iron, gamma iron and delta iron

Body centered cubic iron and face centered cubic iron

26. Which of the following property is desirable for materials used in tools and machines?

Plasticity

Elasticity

Malleability

Ductility

27. Cobalt in steel

Gives ductility, toughness, tensile strength and anti corrosion property

Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties

Improves wear resistance, cutting ability and toughness

Improves cutting ability and reduce hardenability

28. Which of the following statement is incorrect about duralumin?

It has good machining properties

It can be forged

It is prone to age hardening

It is lighter than pure aluminium

29. Taps dies and drills contain carbon

Below 1%

Below 0.5%

Above 1%

Above 2.2%

30. Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio

50 : 20 : 10 : 20

30 : 20 : 30 : 20

50 : 20 : 20 : 10

40 : 30 : 20 : 10

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31. The unit cells

Have the same orientation and their similar faces are parallel

All of the above

Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal

May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice

32. Which is false statement about normalizing? Normalizing is done to

Improve mechanical properties

Induce stresses

Refine grain structure

Reduce segregation in casting

33. Brass contains

70 - 75% copper and rest tin

70% copper and 30% zinc

90% copper and 10% tin

85 - 92% copper and rest tin with little lead and nickel

34. The hardness of steel primarily depends on

Percentage of carbon

Heat treatment employed

Percentage of alloying elements

Shape of carbides and their distribution in iron

35. Gamma-iron occurs between the temperature ranges of

600°C to 900°C

900°C to 1400°C

1400°C to 1530°C

400°C to 600°C

36. A specimen of aluminium metal when observed under microscope shows

H.C.P. structure

F.C.C. crystal structure

A complex cubic structure

B.C.C. crystalline structure

37. The aluminium alloy made by melting aluminium with 2 to 10% magnesium and 1.75% copper is called

Y-alloy

Magnalium

Duralumin

Hindalium

38. In low carbon steels, presence of small quantities of sulphur improves

Hardenability

Machinability

Weldability

Formability

39. Which of the following metal shrinks most from molten state to solid state?

Admiralty metal

Cast steel

Brass

Cast iron

40. There are fourteen atoms in a unit cell of

Face centered cubic space lattice

Close packed hexagonal space lattice

None of these

Body centered cubic space lattice

Engineering Materials Practice Set-3

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