Engineering Materials

131. Super conduction by metals is observed in the temperature range of

1. below 10°K
2. above 100°K
3. around 0°C
4. around 100°C
5. above 1000°C.

View answer

132. Surveying tapes are made of a material having low coefficient of expansion and enough strength. The alloy used is

1. silver metal
2. duralumin
3. Hastelloy
4. monel metal
5. invar.

View answer

133. Taps, dies and drills contain carbon

1. below 0.5%
2. below 1%
3. above 1%
4. above 2.2%
5. nil.

View answer

134. Tensile strength of steel can be safely in-creased by

1. adding carbon up to 2.8%
2. adding carbon up to 6.3%
3. adding carbon up to 0.83%
4. adding small quantities of copper
5. adding copper and carbon.

View answer

135. The ability of a material to resist softening at high temperature is known as

1. creep
2. hot tempering
3. hot hardness
4. fatigue
5. superhardening.

View answer

136. The alloy used for making electrical resistances and heating elements is

1. nichrome
2. invar
3. magnin
4. elinvar
5. peiminvar.

View answer

137. The basic constituents of Hastelloy are

1. aluminium, copper etc.
2. nickel, molybdenum etc.
3. nickel, copper, etc.
4. all of the above
5. none of the above.

View answer

138. The composition of silver solder is

1. silver, copper, zinc
2. silver, tin, nickel
3. silver, lead, zinc
4. silver, copper, aluminium
5. silver, lead, tin.

View answer

139. The correct composition of Babbit metal is

1. 87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
2. 90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
3. 87% Sn, 4% Cu, 8% Sb, 1% Al
4. 82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
5. none of the above.

View answer

140. The correct sequence for descending order of machinability is

1. grey cast iron, low carbon steel, wrought iron
2. low carbon steel, grey cast iron, wrought iron
3. wrought iron,low carbon steel, grey cast iron
4. wrought iron, grey cast iron, low carbon steel
5. grey cast iron, wrought iron, low carbon steel.

View answer