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Mechanical Engg

Sep 03, 2015

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Mechanical Engg

Iron ore is, usually, found in the form of

A.

oxides

B.

carbonates

C.

sulphides

D.

all of these

The hardness of steel increases if it contains

A.

pearlite

B.

ferrite

C.

cementite

D.

martensite

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

A.

in still air

B.

slowly in the furnace

C.

suddenly in a suitable cooling medium

D.

any one of these

The lower critical temperature

A.

decreases as the carbon content in steel increases

B.

increases as the carbon content in steel increases

C.

is same for all steels

D.

depends upon the rate of heating

Nodular cast iron is produced by adding __________ to the molten cast iron.

A.

nickel

B.

chromium

C.

copper

D.

magnesium

Free carbon in iron makes the metal

A.

soft and gives a coarse grained crystalline structure

B.

soft and gives a fine grained crystalline structure

C.

hard and gives a coarse grained crystalline structure

D.

hard and gives a fine grained crystalline structure

The cupola is used to manufacture

A.

pig iron

B.

cast iron

C.

wrought iron

D.

steel

The type of space lattice found in gamma-iron is

A.

face centred cubic space lattice

B.

body centred cubic space lattice

C.

close packed hexagonal space lattice

D.

none of these

The property of a material due to which it breaks with little permanent distortion, is called

A.

brittleness

B.

ductility

C.

malleability

D.

plasticity

Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?

A.

Sulphur

B.

Phosphorus

C.

Manganese

D.

Silicon

The hardness of steel depends upon the

A.

amount of cementite it contains

B.

amount of carbon it contains

C.

contents of alloying elements

D.

method of manufacture of steel

Cartidge brass can be

A.

cold rolled into sheets

B.

drawn into wires

C.

formed into tube

D.

any one of these

Which of the following statement is correct?

A.

The product produced by blastfurnace is called cast iron.

B.

The pig iron is the name given to the product produced by cupola.

C.

The cast iron has high tensile strength.

D.

The chilled cast iron has no graphite.

Blast furnace is used to produce

A.

pig iron

B.

cast iron

C.

wrought iron

D.

steel

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

A.

Steels are heated to 500 to 700 C

B.

Cooling is done slowly and steadily

C.

Internal stresses are relieved

D.

all of these

Which of the following steel making process is being adopted at Rourkela Steel Plant?

A.

Bessemer process

B.

Open-hearth process

C.

Electric process

D.

L-D process

18-4-1 high speed steel contains

A.

vanadium 4%, chromium 18% and tungsten 1%

B.

vanadium 1%, chromium 4% and tungsten 18%

C.

vanadium 18%, chromium 1% and tungsten 4%

D.

none of the above

Grey cast iron has

A.

carbon in the form of free graphite

B.

high tensile strength

C.

low compressive strength

D.

all of these

Induction hardening is basically a

A.

carburising process

B.

surface hardening process

C.

core-hardening process

D.

none of these

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

A.

white cast iron

B.

nodular cast iron

C.

malleable cast iron

D.

alloy cast iron

The strength is the ability of a material to resist

A.

deformation under stress

B.

externally applied forces with breakdown or yielding

C.

fracture due to high impact loads

D.

none of these

The material widely used for making pendulums of clocks is

A.

stainless steel

B.

high speed steel

C.

heat resisting steel

D.

nickel steel

The stiffness is the ability of a material to resist

A.

deformation under stress

B.

fracture due to high impact loads

C.

externally applied forces with breakdown or yielding

D.

none of the above

The blade of a power saw is made of

A.

boron steel

B.

high speed steel

C.

stainless steel

D.

malleable cast iron

In induction hardening __________ is high.

A.

current

B.

voltage

C.

frequency

D.

temperature

The metal suitable for bearings subjected to light loads, is

A.

silicon bronze

B.

white metal

C.

monel metal

D.

phosphor bronze

The property of a material essential for spring materials is

A.

stiffness

B.

ductility

C.

resilience

D.

plasticity

Which of the following material has nearly zero coefficient of expansion?

A.

Stainless steel

B.

High speed steel

C.

Invar

D.

Heat resisting steel

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

A.

nickel

B.

vanadium

C.

cobalt

D.

molybdenum

Which of the following is an amorphous material?

A.

Mica

B.

Silver

C.

Lead

D.

Glass

The machinability of steel is improved by adding

A.

nickel

B.

chromium

C.

nickel and chromium

D.

sulphur, lead and phosphorus

The carbon in the pig iron varies from

A.

0.1 to 0.5%

B.

0.5 to 1%

C.

1 to 5%

D.

5 to 10%

The type of space lattice found in alpha-iron is

A.

face centred cubic space lattice

B.

body centred cubic space lattice

C.

close packed hexagonal space lattice

D.

none of these

The brown smoke during the operation of a bessemer Converter indicates that the

A.

air is burning out silicon and managanese

B.

silicon and manganese has burnt and carbon has started oxidising

C.

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

D.

the brown smoke does not occur during the operation of a bessemer converter

Martensite has needle like structure and is magnetic.

A.

Correct

B.

Incorrect

Monel metal is an alloy of

A.

nickel and copper

B.

nickel and chromium

C.

nickel, chromium and iron

D.

copper and chromium

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

When a low carbon steel is heated upto upper critical temperature

A.

there is no change in grain size

B.

the average grain size is a minimum

C.

the grain size increases very rapidly

D.

the grain size first increases and then decreases very rapidly

The steel widely used for motor car crankshafts is

A.

nickel steel

B.

chrome steel

C.

nickel-chrome steel

D.

silicon steel

Combined carbon in iron makes the metal

A.

soft and gives coarse grained crystalline structure

B.

soft and gives a fine grained crystalline structure

C.

hard and gives a coarse grained crystalline structure

D.

hard and gives a fine grained crystalline structure

Pearlite consists of

A.

13% carbon and 87% ferrite

B.

13% cementite and 87% ferrite

C.

13% ferrite and 87% cementite

D.

6.67% carbon and 93.33% iron

Quenching is not necessary when hardening is done by

A.

case hardening

B.

flame hardening

C.

nitriding

D.

any one of these

Beryllium bronze has

A.

high yield point

B.

high fatigue limit

C.

both (a) and (b)

D.

none of these

The aluminium alloy, mainly used, for anodized utensil manufacture, is

A.

duralumin

B.

Y-alloy

C.

magnalium

D.

hindalium

The toughness of a material __________ when it is heated.

A.

remains same

B.

decreases