Engineering Materials Practice Set-5

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

Phosphor bronze

Nichrome

Babbitt metal

Monel metal

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

Increase endurance strength

Reduce machinability

Increase hardenability

Increase wear resistance

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

Surface decarburisation

Cold working

Nitriding of surface

Shot peening

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

Throat

Stack

Tyres

Bosh

5. Mild steel belongs to the following category

High carbon steel

Alloy steel

Low carbon steel

Medium carbon steel

6. Which is false statement about properties of aluminium?

Wear resistance is very good

Fatigue strength is not high

Creep strength limits its use to fairly low temperatures

Modulus of elasticity is fairly low

7. Delta iron occurs at temperature of

Between 1400°C and 1539°C

Between 910°C and 1400°C

Room temperature

Above melting point

8. Closed packed hexagonal space lattice is found in

Zinc, magnesium, cobalt, cadmium, antimony and bismuth

None of the above

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

Alpha-iron, tungsten, chromium and molybdenum

9. Following elements have face-centered cubic structure

Mg, Zn, Ti, Zr, Br, Cd

All of the above

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

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

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

Silicon and manganese has burnt and carbon has started oxidizing

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

Air is burning out silicon and manganese

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

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11. Neutral solution is one which has pH value

pH value has nothing to do with neutral solution

Equal to 7

Less than 7

Greater than 7

12. Brass is an alloy of

None of these

Copper, tin and zinc

Copper and tin

Copper and zinc

13. Foundry crucible is made of

German silver

Graphite

Mild steel

Lead

14. The steel widely used for motor car crankshafts is

Silicon steel

Nickel-chrome steel

Nickel steel

Chrome steel

15. Recrystallization temperature is one

At which change of allotropic form takes place

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

At which crystals grow bigger in size

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

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

None of these

Eutectic cast irons

Hypereutectic cast irons

Hypoeutectic cast irons

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

Induction hardening

Nitriding

Cyaniding

Electroplating

18. The elastic stress strain behavior of rubber is

Nonlinear

Plastic

Linear

No fixed relationship

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

Large surface wear

Light load and pressure

High pressure and load

Elevated temperatures

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

Slowly in the furnace

In still air

Any one of these

Suddenly in a suitable cooling medium

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21. Malleability of a material can be defined as

Ability to undergo large permanent deformations in compression

All of the above

Ability to recover its original form

Ability to undergo large permanent deformations in tension

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

Twelve

Eighteen

Twenty

Six

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

White cast iron

Nodular cast iron

Malleable cast iron

Alloy cast iron

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

(B) Whiteheart cast iron

(D) None of these

(C) Both (A) and (B)

(A) Blackheart cast iron

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

Creep

Fatigue

Hot tempering

Hot hardness

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

Close packed hexagonal space lattice

None of these

Body centered cubic space lattice

Face centered cubic space lattice

27. The molecules in a solid move

Back and forth like tiny pendulums

In a haphazard way

In a random manner

In circular motion

28. The percentage of carbon in low carbon steel is

0.3%

0.15%

0.5%

0.05%

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

Normalizing

Hot working

Annealing

Tempering

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

Pearlite

Austenite

Ferrite

Cementite

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

Remain constant

First increase and then decrease

Decrease

Increase

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

Has a fixed structure under all conditions

Has its atoms distributed in a random pattern

Exists in several crystal forms at different temperatures

Responds to heat treatment

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

The average grain size is a minimum

The grain size first increases and then decreases very rapidly

The grain size increases very rapidly

There is no change in grain size

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

None of the above

Fracture due to high impact loads

Externally applied forces with breakdown or yielding

Deformation under stress

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

Vitrified clay

Asbestos cement

Concrete

Cast iron

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

Endurance

Plastic deformation

Fatigue

Creep

37. Balls for ball bearings are made of

Mild steel

Cast iron

Carbon-chrome steel

Stainless steel

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

Resilience

Plasticity

Stiffness

Ductility

39. Isotropic materials are those which have the same

Thermal properties in all directions

Elastic properties in all directions

Electric and magnetic properties in all directions

Stresses induced in all directions

40. White cast iron has

Carbon in the form of carbide

All of these

High compressive strength

Low tensile strength

Engineering Materials Practice Set-5

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