Engineering Materials Practice Set-3

Page 1 of 4

1. Cementite consist of

6.67% carbon and 93.33% iron

13% carbon and 87% ferrite

13% ferrite and 87% cementite

13% cementite and 87% ferrite

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

B.C.C. crystalline structure

H.C.P. structure

F.C.C. crystal structure

A complex cubic structure

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

0.55 to 1.0%

0.20 to 0.45%

0.05 to 0.20%

0.45 to 0.55%

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

Malleability

Elasticity

Plasticity

Ductility

5. Hematite iron ore contains iron about

70%

55%

45%

30%

6. The tensile strength of wrought iron is maximum

Along the lines of slag distribution

Perpendicular to lines of slag distribution

None of the above

Uniform in all directions

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

1000 to 1100 VPN

1500 VPN

600 VPN

250 VPN

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

Brittleness

Strength

Stiffness

Toughness

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

Alpha iron and beta iron

Body centered cubic iron and face centered cubic iron

Alpha iron, gamma iron and delta iron

Alpha iron, beta iron and gamma iron

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

Malleability

Ductility

Brittleness

Plasticity

Page 2 of 4

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

Admiralty metal

Cast steel

Cast iron

Brass

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

5 to 7%

1.2%

2.5 to 4.5%

0.5 to 1%

13. The hardness of steel primarily depends on

Percentage of alloying elements

Heat treatment employed

Percentage of carbon

Shape of carbides and their distribution in iron

14. The unit cells

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

Have the same orientation and their similar faces are parallel

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

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

Strength

Brittleness

Toughness

Stiffness

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

Acidic

Brittle

Neutral

Basic

17. The machinability of steel is improved by adding

Chromium

Sulphur, lead and phosphorus

Nickel and chromium

Nickel

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

Chromium

Copper

Nickel

Silicon

19. Brass contains

70% copper and 30% zinc

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

70 - 75% copper and rest tin

90% copper and 10% tin

20. Tungsten in steel

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

Improves wear resistance, cutting ability and toughness

Page 3 of 4

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

Bosh

Hearth

Stack

Throat

22. The usual composition of a soldering alloy is

Tin, lead and small percentage of antimony

Tin, lead and silver

Tin and copper

Tin and lead

23. Corundum contains more than 95%

Steel

SiO₂

Al₂O₃

MgO

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

Formability

Machinability

Weldability

Hardenability

25. Ductility of a material can be defined as

Ability to undergo large permanent deformations in tension

Ability to recover its original form

Ability to undergo large permanent deformations in compression

All of the above

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

Y-alloy

Duralumin

Magnalium

Hindalium

27. Gamma-iron occurs between the temperature ranges of

400°C to 600°C

600°C to 900°C

900°C to 1400°C

1400°C to 1530°C

28. Taps dies and drills contain carbon

Below 0.5%

Above 1%

Above 2.2%

Below 1%

29. There are fourteen atoms in a unit cell of

Face centered cubic space lattice

None of these

Body centered cubic space lattice

Close packed hexagonal space lattice

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

0.6 to 0.8%

0.35 to 0.45%

0.4 to 0.6%

0.04%

Page 4 of 4

31. Points of arrest for iron correspond to

There is nothing like points of arrest

Stages at which allotropic forms change

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

Stages at which properties do not change with increase in temperature

32. 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

40 : 30 : 20 : 10

50 : 20 : 20 : 10

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

Improve mechanical properties

Induce stresses

Refine grain structure

Reduce segregation in casting

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

Line defect

None of these

Point defect

Surface defect

35. Cobalt in steel

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

Gives ductility, toughness, tensile strength and anti corrosion property

Improves wear resistance, cutting ability and toughness

Improves cutting ability and reduce hardenability

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

Tungsten, chromium, titanium

Tungsten, titanium, vanadium

Chromium, titanium, vanadium

Vanadium, chromium, tungsten

37. 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

38. The coke in the charge of blast furnace

Controls the grade of pig iron

Forms a slag by combining with impurities

Acts as an iron bearing mineral

Supplies heat to reduce ore and melt the iron

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

It can be forged

It is lighter than pure aluminium

It has good machining properties

It is prone to age hardening

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

White metal

Silicon bronze

Phosphor bronze

Monel metal

Engineering Materials Practice Set-3

Related

Leave a ReplyCancel reply

Secured Payments

Protection

Engineering Materials Practice Set-3

Share this Now with Friends:

Related

Leave a ReplyCancel reply

Secured Payments

Protection