Materials and Construction

221. Invar contains the highest percentage of

1. Vanadium
2. Iron
3. Tungsten
4. Cobalt

View answer

222. Invar used in thermocouples is an alloy of nickel and

1. Iron
2. Copper
3. Chromium
4. Lead

View answer

223. Iron alloyed with carbon upto 2% is called

1. Pig iron
2. Wrought iron
3. High carbon steel
4. None of these

View answer

224. Iron rust is

1. Ferrous oxide
2. Hydrated ferric oxide
3. Powdered iron
4. Ferric sulphide

View answer

225. Karbate is

1. A mixture of iron dust and saw dust
2. Carbon impregnated with resin (usually Bakelite)
3. An acid resistant material
4. Both (B) and (C)

View answer

226. Kel-F is a material, which is

1. Chemically known as Polychlorotrifluoroethylene (PTFE)
2. Having excellent chemical & high temperature resistance (upto 200°C)
3. Having elastomeric properties
4. All (A), (B) and (C)

View answer

227. Lead

1. Is the hardest metal in common use
2. Is the lightest metal in common use
3. Cannot be scratched by finger nails
4. Cannot be work hardened

View answer

228. Lead alone is not used in storing equipment, because it

1. Is very costly
2. Corrodes easily
3. Is having low creep strength
4. None of these

View answer

229. Lead is

1. Not resistant to corrosion
2. Used as a cathodic material
3. Not used as pigment (in its compound forms) for paints
4. Used as a shock absorber (in mattress form) between the foundation and steel framework of skyscraper buildings

View answer

230. Lead lined equipments & vessels are suitable for handling

1. Hydrochloric acid (10%)
2. Nitric acid
3. Sulphuric acid upto 60°C
4. All (A), (B) and (C)

View answer