Engineering Materials Objectives Part 06
101. The percentage of carbon in cast iron is “2 to 4 percent”.
102 . Hardness of a material is resistance to “scratching”.
103 . For elastic materials stress and strain are related by “Hooke’s law”.
104 . Main constituents of glass is “SiO2”.
105 . The permeability and permittivity of a medium are “independent of each other”.05 .
106 . An atom in a crystal vibrates at a frequency determined by “the temperature of the crystal”.
107 . Alloying elements added to steel are “Molybdenum, Vanadium and Chromium”.
108 . Mer is “the smallest repetitive unit in a polymer”.
109 . Bakelite is a “Phenol formaldehyde resin”.
110 . “Silver” has the maximum electrical conductivity.
11 . “Nichrome” is particularly suitable for use in standard resistance coils and in
instrument shunts.
112 . Magnetic recording tape is most made from “ferric-oxide”.
113 . An alloy of copper and zinc is called “brass”.
114 . Permivar is an alloy of “45% Ni + 30% Cu + 25% Co” composition.
115 . Bronze is an alloy of “Copper and Tin”.
116 . Stainless steel is an alloy of “Iron, Chromium and Molybdenum”.
117 . The percentage of carbon in mild steel is “0.08 to 0.3%”.
118 . Gun metal is an alloy of “86% Cu + 9% Zn + 5% Sn”.
119 . Silicon steels used for electrical purposes have silicon percentage “0.5%”.
120 . The resistivity of a metal is a function of temperature because “the amplitude of
vibration of the atom varies with temperature”.
