MCQ
61. 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
62. 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
63. The percentage carbon content in wrought iron is about--
0.02
0.2
0.1
0.4
64. Which is binding material?
Sand
Cement
Khoa
Rod
65. Iron carbon alloy containing carbon --4.3% carbon are known as hyper-eutectic cast Irons.
usual to
more than
less than
none of them
66. Steel containing 0.8 to 1.5% carbon is known as—
mild steel
medium carbon
dead mild steel
high carbon steel
67. 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%
68. A steel alloy containing 36% nickel is called--
stainless
invar
high speed steel
heat resenting steel
69. 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
70. The carbon in the pig iror varier from-
0.1 to 0.5%
1 to 5 %
0.5 to 15%
5 to 10%
71. 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
72. 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
73. Taps, dies and drills contain carbon-
below 0.5%
below 1%
above 1%
above 2.2%
74. The material commonly used for machine tool bodies is-.
mild steel
brass
aluminium
cast iron
75. In the lower part of the blast furnace (Zone of fusion) the temperature is—
800-1000°C
1500-1700°C
400-700°C
1200-1300°C
76. The austenitic stainless steel centrums-
18% chromium and 8% nickel
8% chromium and 18% nickel
14% nickel and 0.35% carbon
14% nickel and 0.35% carbon
77. 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
78. What is used as joining medium in brazing operation?
Copper-Zinc alloy
Lead-Tin alloy
Nickel-Silver alloy
All of the above
79. A steel with carbon is --known as hyper- eutectoid steel--
0.87%
below 0.8%
above 0.8%
None of them
80. Nodular cast iron is produced by adding the molten cast iron-
Nickel
Copper
Chromium
Magnesium