Engineering Materials Practice Set-6

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1. Chromium when added to steel _________ the tensile strength.

Increases

Does not effect

None of these

Decreases

2. Chilled cast iron has

No graphite

Graphite as its basic constituent of composition

A very high percentage of graphite

A low percentage of graphite

3. Steel containing ferrite and pearlite is

Tough

Hard and tough

Hard

Soft

4. Carbon steel is

Extensively used for making cutting tools

Made by adding carbon in steel

Refined from cast iron

An alloy of iron and carbon with varying quantities of phosphorus and sulphur

5. The purpose of heat treatment is to

Relieve the stresses set up in the material after hot or cold working

Change grain size

Any one of these

Modify the structure of the material

6. Induction hardening is basically a

Carburising process

None of these

Core hardening process

Surface hardening process

7. In grey cast iron, carbon is present in the form of

Flakes

Cementite

Free carbon

Spheroids

8. 'Killed steels' are those steels

Which are destroyed by burning

In which carbon is completely burnt

Which after their destruction are recycled to produce fresh steel

Which are deoxidized in the ladle with silicon and aluminium

9. Grey cast iron has

High tensile strength

Low compressive strength

Carbon in the form of free graphite

All of these

10. Which of the following statements are true for annealing of steels?

Cooling is done slowly and steadily

Steels are heated to 500 to 700°C

Internal stresses are relieved

All of these

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11. Nodular cast iron is produced by adding ________ to the molten cast iron.

Copper

Nickel

Chromium

Magnesium

12. Cast iron is characterized by minimum of following percentage of carbon

2%

0.8%

0.2%

1.3%

13. In nodular iron, graphite is in the form of

Cementite

Flakes

Spheroids

Free carbon

14. In induction hardening ________ is high.

Temperature

Voltage

Frequency

Current

15. Manganese is added in low carbon steel to

All of the above

Make the steel ductile and of good bending qualities

Make the steel tougher and harder

Raise the yield point

16. Wrought iron is

Hard

Highly resistant to corrosion

Heat treated to change its properties

High in strength

17. The alloying element which can replace tungsten in high speed steels is

Vanadium

Nickel

Molybdenum

Cobalt

18. Paramagnetic alpha iron changes to gamma iron at

910°C

1539°C

770°C

1440°C

19. In mottled cast iron, carbon is available in

Free form

Combined form

Partly in free and partly in combined state

Nodular form

20. Malleable cast iron is produced

From white cast iron by annealing process

None of these

By adding magnesium to molten cast iron

By quick cooling of molten cast iron

Page 3 of 4

21. Pick up wrong statement about wrought iron

It melts at 1535°C

It is very soft and ductile

It contains carbon of the order of 0 to 0.25%

It is made by adding suitable percentage of carbon to molten iron and subjecting the product to repeated hammering and rolling

22. When the steel is normalized, its

Ductility decreases

Yield point increases

All of these

Ultimate tensile strength increases

23. Monel metal is an alloy of

Nickel, Chromium and iron

Nickel and copper

Copper and chromium

Nickel and chromium

24. An important property of malleable cast iron in comparison to grey cast iron is the high

Ductility

Hardness

Carbon content

Compressive strength

25. The crystal of alpha iron is

Body centered cubic

Cubic structure

Hexagonal close packed

Face centered cubic

26. Cast iron has

Its elastic limit close to the ultimate breaking strength

High tensile strength

High ductility

All of the above

27. Combined carbon in iron makes the metal

Soft and gives coarse grained crystalline structure

Soft and gives a fine grained crystalline structure

Hard and gives a coarse grained crystalline structure

Hard and gives a fine grained crystalline structure

28. Sulphur in pig iron tends to make it

Ductile

Soft

Hard

Tough

29. Iron is

Ferromagnetic

Paramagnetic

Ferroelectric

Dielectric

30. The unique property of cast iron is its high

Ductility

Malleability

Surface finish

Damping characteristics

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31. Gamma iron exits at following temperature

Between 1400°C and 1539°C

Between 910°C and 1400°C

Near melting point

Room temperature

32. The following types of materials are usually the most ductile

All of the above

Face centered cubic lattice

Body centered cubic lattice

Hexagonal close packed lattice

33. Pure iron is the structure of

Ferrite

Pearlite

Austenite

Ferrite and cementite

34. The crystal structure of gamma iron is

Hexagonal close packed

Cubic structure

Body centered cubic

Face centered cubic

35. In malleable iron, carbon is present in the form of

Cementite

Nodular aggregates of graphite

Flakes

Free carbon

36. The lower critical temperature

Is same for all steels

Increases as the carbon content in steel increases

Decreases as the carbon content in steel increases

Depends upon the rate of heating

37. Which of the following is an amorphous material?

Silver

Lead

Mica

Glass

38. In high speed steels, manganese is used to tougher the metal and to increase its

Critical temperature

Hardness

Melting point

Yield point

39. The metal suitable for bearings subjected to light loads, is

White metal

Monel metal

Phosphor bronze

Silicon bronze

40. Annealing of white cast iron results in production of

Grey iron

Nodular iron

Malleable iron

Spheroidal iron

Engineering Materials Practice Set-6

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