Engineering Materials Practice Set-5

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1. Tin base white metals are used where the bearings are subjected to

Large surface wear

Elevated temperatures

Light load and pressure

High pressure and load

2. In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled

Any one of these

In still air

Slowly in the furnace

Suddenly in a suitable cooling medium

3. Which of the following constituents of steels is softest and least strong?

Pearlite

Austenite

Cementite

Ferrite

4. Following elements have face-centered cubic structure

A iron (below 910°C and between 1400 to 1539°C), W

All of the above

Mg, Zn, Ti, Zr, Br, Cd

Gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt

5. Malleability of a material can be defined as

Ability to undergo large permanent deformations in tension

Ability to recover its original form

All of the above

Ability to undergo large permanent deformations in compression

6. The type of space lattice found in alpha-iron is

Body centered cubic space lattice

Face centered cubic space lattice

None of these

Close packed hexagonal space lattice

7. A small percentage of boron is added to steel in order to

Increase hardenability

Increase endurance strength

Reduce machinability

Increase wear resistance

8. A material is known as allotropic or polymorphic if it

Responds to heat treatment

Has its atoms distributed in a random pattern

Exists in several crystal forms at different temperatures

Has a fixed structure under all conditions

9. The steel widely used for motor car crankshafts is

Nickel-chrome steel

Nickel steel

Chrome steel

Silicon steel

10. The ability of a material to resist softening at high temperature is known as

Hot tempering

Creep

Fatigue

Hot hardness

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11. Iron-carbon alloys containing 1.7 to 4.3% carbon are known as

Eutectic cast irons

Hypereutectic cast irons

None of these

Hypoeutectic cast irons

12. The coordination number of a face centered cubic space lattice is

Twelve

Eighteen

Twenty

Six

13. Which is false statement about case hardening? Case hardening is done by

Nitriding

Electroplating

Cyaniding

Induction hardening

14. Lead is poured into the joint between two pipes. These pipes may be made of

Asbestos cement

Cast iron

Concrete

Vitrified clay

15. Neutral solution is one which has pH value

Less than 7

pH value has nothing to do with neutral solution

Greater than 7

Equal to 7

16. Which is false statement about properties of aluminium?

Wear resistance is very good

Modulus of elasticity is fairly low

Fatigue strength is not high

Creep strength limits its use to fairly low temperatures

17. Recrystallization temperature is one

At which crystals first start forming from molten metal when it is cooled

At which crystals grow bigger in size

At which new spherical crystals first begin to form from the old deformed one when a strained metal is heated

At which change of allotropic form takes place

18. Slow plastic deformation of metals under a constant stress is known as

Plastic deformation

Fatigue

Creep

Endurance

19. Delta iron occurs at temperature of

Between 1400°C and 1539°C

Room temperature

Above melting point

Between 910°C and 1400°C

20. The molecules in a solid move

Back and forth like tiny pendulums

In a random manner

In circular motion

In a haphazard way

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21. The charge is fed into the blast furnace through the

Bosh

Throat

Stack

Tyres

22. Closed packed hexagonal space lattice is found in

Gamma-iron, aluminium, copper, lead, silver and nickel

None of the above

Zinc, magnesium, cobalt, cadmium, antimony and bismuth

Alpha-iron, tungsten, chromium and molybdenum

23. Which of the following metal is used in making electrical resistance wire for electric furnaces and heating elements?

Nichrome

Babbitt metal

Monel metal

Phosphor bronze

24. Materials after cold working are subjected to following process to relieve stresses

Tempering

Hot working

Annealing

Normalizing

25. The brown smoke during the operation of a Bessemer converter indicates that the

Air is burning out silicon and manganese

The brown smoke does not occur during the operation of a Bessemer converter

The converter must be titled to remove the contents of the converter

Silicon and manganese has burnt and carbon has started oxidizing

26. Balls for ball bearings are made of

Carbon-chrome steel

Stainless steel

Cast iron

Mild steel

27. The property of a material essential for spring materials is

Plasticity

Resilience

Ductility

Stiffness

28. White cast iron has

Low tensile strength

High compressive strength

All of these

Carbon in the form of carbide

29. Which of the following is not the correct method of increasing fatigue limit?

Surface decarburisation

Cold working

Nitriding of surface

Shot peening

30. Brass is an alloy of

Copper and zinc

None of these

Copper and tin

Copper, tin and zinc

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31. Isotropic materials are those which have the same

Elastic properties in all directions

Thermal properties in all directions

Electric and magnetic properties in all directions

Stresses induced in all directions

32. The percentage of carbon in low carbon steel is

0.05%

0.5%

0.3%

0.15%

33. When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces

Alloy cast iron

Nodular cast iron

White cast iron

Malleable cast iron

34. The elastic stress strain behavior of rubber is

Plastic

No fixed relationship

Linear

Nonlinear

35. Which of the following display properties similar to that of steel?

(A) Blackheart cast iron

(B) Whiteheart cast iron

(C) Both (A) and (B)

(D) None of these

36. The ultimate tensile strength of low carbon steel by working at a high strain rate will

First increase and then decrease

Remain constant

Decrease

Increase

37. Foundry crucible is made of

German silver

Mild steel

Graphite

Lead

38. When low carbon steel is heated up to lower critical temperature

The average grain size is a minimum

There is no change in grain size

The grain size first increases and then decreases very rapidly

The grain size increases very rapidly

39. Mild steel belongs to the following category

Low carbon steel

High carbon steel

Medium carbon steel

Alloy steel

40. The stiffness is the ability of a material to resist

None of the above

Fracture due to high impact loads

Deformation under stress

Externally applied forces with breakdown or yielding

Engineering Materials Practice Set-5

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