51. Steel contains
(a) 80% or more iron
(b) 50% or more iron
(c) alloying elements like chromium, tungsten nickel and copper
(d) elements like phosphorus, sulfur and silicon in varying quantities
(e) high quantities of sulfur.
Ans: b
52. Carbon steel is
(a) made by adding carbon in steel
(b) refined from cast iron
(c) an alloy of iron and carbon with varying quantities of phosphorus and sulfur
(d) extensively used for making cutting tools
(e) extremely brittle.
Ans: c
53. Annealing of white cast iron results in production of
(a) malleable iron
(b) nodular iron
(c) spheroidal iron
(d) grey iron
(e) none of the above.
Ans: a
54. ‘Killed steels’ are those steels
(a) which are destroyed by burning^
(b) which after their destruction are recycled to produce fresh steel
(c) which are deoxidised in the ladle with silicon and aluminium
(d) in which carbon is completely burnt
(e) which have poor properties due to improper manufacturing.
Ans: c
55. Hardness of steel depends on
(a) amount of carbon it contains
(b) the shape and distribution of the car-bides in iron
(c) method of fabrication
(d) contents of alloying elements
(e) the quality of ore from which it is made.
Ans: b
56. Maximum percentage of carbon in ferrite is
(a) 0.025%
(b) 0.06%
(c) 0.1%
(d) 0.25%
(e) 0.8%.
Ans: a
57. Maximum percentage of carbon in austenite is
(a) 0.025%
(b) 0.26%
(c) 0.8%
(d) 1.25%
(e) 1.7%.
Ans: e
58. Corrosion resistance of steel is increased by addition of
(a) chromium and nickel
(b) sulphur, phosphorus, lead
(c) vanadium, aluminium
(d) tungsten, molybdenum, vanadium, chromium
(e) zinc.
Ans: a
59. In which of the following cases, consideration of creep is important
(a) flywheel of steam engine
(b) cast iron pipes”
(c) cycle chains
(d) gas turbine blades
(e) piston I.C. engine.
Ans: d
60. The most effective inhibitor of grain growth, when added in small quantities is
(a) carbon
(b) vanadium
(c) manganese
(d) cobalt
(e) copper.
Ans: b
61. Depth of hardness of steel is increased by addition of
(a) nickel
(b) chromium
(c) tungsten
(d) vanadium
(e) ell of the above.
Ans: b
62. Railway rails are normally made of
(a) mild steel
(b) alloy steel
(c) high carbon
(d) tungsten steel
(e) cast iron steel.
Ans: c
63. Pick up the wrong statement
(a) aluminum in steel results in excessive grain growth
(b) manganese in steel induces hardness
(c) nickel and chromium in steel help in raising the elastic limit and improve the resilience and ductility
(d) tungsten in steels improves magnetic properties and harden ability
(e) sulphur, phosphorous and lead improve machining properties of steel.
Ans: a
64. Pick up the wrong statement Nickel and chromium in steel help in
(a) providing corrosion resistance
(b) improving machining properties
(c) providing high strength at elevated temperatures
(d) raising the elastic limit
(e) improving the resilience and ductility.
Ans: b
65. Machining properties of steel are improved by adding
(a) sulphur, lead, phosphorous
(b) silicon, aluminium, titanium
(c) vanadium, aluminium
(d) chromium, nickel
(e) lubricants.
Ans: a
66. Eutectoid steel contains following percentage of carbon
(a) 0.02%
(b) 0.3%
(c) 0.63%
(d) 0.8%
(e) 1.2%.
Ans: d
67. The basic constituents of Hastelloy are
(a) aluminium, copper etc.
(b) nickel, molybdenum etc.
(c) nickel, copper, etc.
(d) all of the above
(e) none of the above.
Ans: b
68. Basic constituents of Monel metal are
(a) nickel, copper
(b) nickel, molybdenum
(c) zinc, tin, lead
(d) nickel, lead and tin
(e) none of the above.
Ans: a
69. German silver is an alloy of
(a) silver and some impurities
(b) refined silver
(c) nickel, copper and zinc
(d) nickel and copper
(e) silver and gold.
Ans: c
70. Surveying tapes are made of a material having low coefficient of expansion and enough strength. The alloy used is
(a) silver metal
(b) duralumin
(c) Hastelloy
(d) monel metal
(e) invar.
Ans: e
71. A cold chisel is made of
(a) mild steel
(b) cast iron
(c) H.S.S.
(d) high carbon
(e) german silver.
Ans: d
72. An engineer’s hammer is made of
(a) cast iron
(b) forged steel
(c) mild steel
(d) high carbon steel
(e) H.S.S.
Ans: d
73. Inconel is an alloy of
(a) nickel, chromium and iron
(b) nickel, copper
(c) nickel, chromium
(d) nickel, zinc
(e) nickel, lead.
Ans: a
74. By severely deforming a metal in a particular direction it becomes
(a) ductile
(b) malleable
(c) homogeneous
(d) isotropic
(e) anisotropic.
Ans: e
75. Solder is an alloy consisting of
(a) tin, antimony, copper
(b) tin and copper
(c) tin and lead
(d) lead and zinc
(e) lead and copper.
Ans: b