Engineering Materials Practice Set-5

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

Air is burning out silicon and manganese

Silicon and manganese has burnt and carbon has started oxidizing

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

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

2. Foundry crucible is made of

Lead

Graphite

Mild steel

German silver

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

Tyres

Bosh

Stack

Throat

4. Delta iron occurs at temperature of

Above melting point

Between 910°C and 1400°C

Between 1400°C and 1539°C

Room temperature

5. Isotropic materials are those which have the same

Stresses induced in all directions

Electric and magnetic properties in all directions

Elastic properties in all directions

Thermal properties in all directions

6. 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

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

Cementite

Pearlite

Austenite

Ferrite

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

Surface decarburisation

Shot peening

Cold working

Nitriding of surface

9. Balls for ball bearings are made of

Stainless steel

Carbon-chrome steel

Cast iron

Mild steel

10. 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

Suddenly in a suitable cooling medium

Any one of these

In still air

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11. The percentage of carbon in low carbon steel is

0.05%

0.5%

0.3%

0.15%

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

(C) Both (A) and (B)

(B) Whiteheart cast iron

(A) Blackheart cast iron

(D) None of these

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

Nitriding

Cyaniding

Induction hardening

Electroplating

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

Hypereutectic cast irons

Eutectic cast irons

None of these

Hypoeutectic cast irons

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

Eighteen

Twelve

Six

Twenty

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

Hot tempering

Hot hardness

Creep

Fatigue

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

Stiffness

Ductility

Resilience

Plasticity

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

Fracture due to high impact loads

None of the above

Deformation under stress

Externally applied forces with breakdown or yielding

19. Neutral solution is one which has pH value

Greater than 7

Less than 7

Equal to 7

pH value has nothing to do with neutral solution

20. Brass is an alloy of

Copper and tin

None of these

Copper, tin and zinc

Copper and zinc

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

Annealing

Hot working

Normalizing

Tempering

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

Phosphor bronze

Babbitt metal

Monel metal

Nichrome

23. Malleability of a material can be defined as

Ability to undergo large permanent deformations in compression

Ability to recover its original form

All of the above

Ability to undergo large permanent deformations in tension

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

Asbestos cement

Vitrified clay

Concrete

Cast iron

25. Recrystallization temperature is one

At which change of allotropic form takes place

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

26. Which is false statement about properties of aluminium?

Modulus of elasticity is fairly low

Wear resistance is very good

Fatigue strength is not high

Creep strength limits its use to fairly low temperatures

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

Face centered cubic space lattice

Body centered cubic space lattice

None of these

Close packed hexagonal space lattice

28. White cast iron has

All of these

Low tensile strength

Carbon in the form of carbide

High compressive strength

29. The molecules in a solid move

In a random manner

In circular motion

Back and forth like tiny pendulums

In a haphazard way

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

Malleable cast iron

White cast iron

Nodular cast iron

Alloy cast iron

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

Responds to heat treatment

Has a fixed structure under all conditions

Has its atoms distributed in a random pattern

Exists in several crystal forms at different temperatures

32. Mild steel belongs to the following category

Alloy steel

High carbon steel

Medium carbon steel

Low carbon steel

33. The steel widely used for motor car crankshafts is

Nickel-chrome steel

Nickel steel

Silicon steel

Chrome steel

34. Following elements have face-centered cubic structure

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

Mg, Zn, Ti, Zr, Br, Cd

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

All of the above

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

Increase endurance strength

Increase wear resistance

Reduce machinability

Increase hardenability

36. The elastic stress strain behavior of rubber is

No fixed relationship

Linear

Plastic

Nonlinear

37. Closed packed hexagonal space lattice is found in

Alpha-iron, tungsten, chromium and molybdenum

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

None of the above

Zinc, magnesium, cobalt, cadmium, antimony and bismuth

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

Elevated temperatures

Large surface wear

High pressure and load

Light load and pressure

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

Creep

Plastic deformation

Fatigue

Endurance

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

Decrease

Remain constant

First increase and then decrease

Increase

Engineering Materials Practice Set-5

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