176. Constantant an alloy used in thermocouples is an alloy of
(a) copper and tin
(b) copper and zinc
(c) copper and iron
(d) copper and nickel
(e) copper and chromium.
Ans: d
177. White metal contains
(a) 63 to 67% nickel and 30% copper
(b) 88% copper and 10% tin and rest zinc
(c) alloy of tin, lead and cadmium
(d) silver and chromium
(e) malleable cast iron and silver.
Ans: c
178. German silver contains
(a) 1% silver
(b) 2.5% silver
(c) 5% silver
(d) 10% silver
(e) 100% silver.
Ans: c
179. Which of the following has highest specific strength of all structural materials
(a) magnesium alloys
(b) titanium alloys
(c) chromium alloys
(d) magnetic steel alloys
(e) none of the above.
Ans: b
180. Dow metal contains
(a) 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
(b) 92.5% aluminium and, 4% copper, 2% nickel and 1.5% Mg
(c) J 0% aluminium and 90% copper
(d) 90% magnesium and 9% aluminium with some copper
Ans: d
181. Foundry crucible is made of
(a) mild steel
(b) german silver
(c) lead
(d) cast iron
(e) graphite.
Ans: e
182. Age-hardening is related with
(a) stainless steel
(b) gun metal
(c) german silver
(d) duralumin
(e) cast iron.
Ans: d
183. Aluminium bronze contains
(a) 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
(b) 92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
(c) 10% aluminium and 90% copper
(d) 90% magnesium and 9% aluminium with some copper
(e) 10% aluminium and 90% tin.
Ans: c
184. Babbit metal is a
(a) lead base alloy
(b) tin base alloy
(c) copper base alloy
(d) all of the above
(e) (a) and (c) above.
Ans: e
185. The correct composition of Babbit metal is
(a) 87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
(b) 90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
(c) 87% Sn, 4% Cu, 8% Sb, 1% Al
(d) 82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
(e) none of the above.
Ans: a
186. DuraJomin contains
(a) 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
(b) 92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg
(c) 10% aluminium and 90% copper
(d) 90% magnesium and 9% aluminium with some copper
(e) 94% aluminium and 6% tin.
Ans: a
187. Neutral solution is one which has pH value
(a) greater than 7
(b) less than 7
(c) equal to 7
(d) pH value has nothing to do with neutral solution
(e) none of the above.
Ans: c
188. Acidic solution is one which has pH value
(a) greater than 7
(b) less than 7
(c) equal to 7
(d) pH value has nothing to do with neutral solution
(e) none of the above.
Ans: b
189. Basic solution is one which has pH value
(a) greater than 7
(b) equal to 7
(c) less than 7
(d) pH value has nothing to do with basic solution
(e) none of the above.
Ans: a
190. Following elements have face-centred cubic structure
(a) gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
(b) Mg, Zn, Ti, Zr, Br, Cd
(c) a iron (below 910°C and between 1400 to 1539°C), W
(d) all of the above
(e) none of the above.
Ans: a
191. Recrystallisation temperature can belowered by
(a) purification of metal
(b) grain refinement
(c) working at lower temperature
(d) all of the above
(e) none of the above.
Ans: d
192. Pearlite is a combination of
(a) ferrite and cementite
(b) cementite and gamma iron
(c) ferrite and austenite
(d) ferrite and iron graphite
(e) pearlite and ferrite.
Ans: a
193. Austenite rs a combination of
(a) ferrite and cementite
(b) cementite and gamma iron
(c) ferrite and austenite
(d) ferrite and iron graphite
(e) pearlite and ferrite.
Ans: b
194. The transistor is made of
(a) silver
(b) gold
(c) copper
(d) germanium
(e) german silver.
Ans: d
195. Lead is poured into the joint between two pipes. These pipes may be made of
(a) cast iron
(b) vitrified clay
(c) asbestos cement
(d) concrete
(e) mild steel.
Ans: a