MCQ
701.
Steel containing 0.8 to 1.5% carbon is known as—
mild steel
medium carbon
dead mild steel
high carbon steel
702.
Cobalt in steel—
improves wear resistance, cuttinability and toughness
refines grain size and produces les tendency to carburisation, improve corrosion and heat resistant proper ties
improves cutting ability and reduce hardenability
gives ductility, toughness, tensile strength and anti-corrosion property
703.
Nodular cast iron is produced by adding the molten cast iron-
Nickel
Copper
Chromium
Magnesium
704.
Silicon in cast iron-
Incrouse hardness and brittleness
Maker the iron write and hard
Aids fusibility and fluidity
Makes the iron soft and easily Machinable
705.
Austenite is a combination of--
ferritc and cementite
cementite and gamma iron
ferrite and austenite
ferrite and iron graphite
706.
The percentage of carbon in low carbon steel is—
0.05%
0.15%
0.3%
0.5%
707.
Duralumin contains—
94% aluminium, 4% copper and 0.5% Mn. Mg. Si and Fe
10% aluminiunt and 90% copper
90% magnesium and alumunium with some copper
92.5% aluminium, 40% copper, 2%, nickel, and 1.5% Mg
708.
Grey cast iron--
contains 1.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten
is also known as chilled cast iron and is obtained by cooling rapidly. It is almost non-machinable
is produced by annealing process. It is soft, tough and easily machine metal
is produced by small additions of magnesium (or cerium) in the ladle. Graphite is in nodular or spheroida form and is well dispersed throughout the material
709.
The transistor is made of--
silver
gold
copper
germanium
710.
Following elements have face-centred cubic structure—
gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
Mg, Zn. Ti. Zr, Br, Cd
a iron (below 910°C and between1400 10 1539°C), W
all of the above
711.
Iron carbon alloy containing carbon --4.3% carbon are known as hyper-eutectic cast Irons.
usual to
more than
less than
none of them
712.
Which of the following impunity in the cast iron promoter graphite module formation and increase the fluidity of the molten metal?
Sulphur
Manganese
Phorphorus
Silicon
713.
The material commonly used for machine tool bodies is-.
mild steel
brass
aluminium
cast iron
714.
Muntz metal (yellow brass) contains—
70% copper and 30% zinc
60% copper and 40% zinc
60% copper and 30% zinc
60.45% copper, 35.2% zinc and 5.35% nickel
715.
The carbon in the pig iror varier from-
0.1 to 0.5%
1 to 5 %
0.5 to 15%
5 to 10%
716.
Drop forging dies contain carbon of the order of --
0.1 to 0.2%
0.25 0.5%
0.6 to 0.7%
0.7 to 0.9%
717.
A steel alloy containing 36% nickel is called--
stainless
invar
high speed steel
heat resenting steel
718.
The correct composition of Babbit metal is—
87.75% Sn, 4% Cu, 8% Sb. 0.25% Bi
90% Sn, 2% Cu, 4% Sb. 2% Bi, 2% Mg
87% Sn, 4% Cu, 8% Sb, 1% Al
82% Sn, 4% Cu, 8% Sb, 3% Al. 35% Mg
719.
The percentage carbon content in wrought iron is about--
0.02
0.2
0.1
0.4
720.
Taps, dies and drills contain carbon-
below 0.5%
below 1%
above 1%
above 2.2%