Materials and Construction

141. Constituents of stellite are

1. Zinc, copper and nickel
2. Cobalt, chromium and tungsten
3. Zinc, aluminium and nickel
4. Nickel, cobalt and vanadium

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142. Containers made of high silicon cast iron (14% Si) are not suitable for the storage of

1. Acetic acid
2. Benzoic & boric acids
3. Phosphoric acid (95%) & sulphuric acid (95%)
4. Hydrochloric acid (concentrated)

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143. Copper has very low

1. Malleability
2. Ductility
3. Tensile strength
4. Thermal & electrical conductivity

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144. Copper is dissolved from its ore by H2SO4 in a percolation tank made of

1. Wood
2. Stainless steel
3. Reinforced concrete lined with lead
4. High silicon iron (14% Si)

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145. Corrosion involves exchange of electrons in _________ corrosion.

1. Chemical
2. Electrochemical
3. Both (A) & (B)
4. Neither (A) nor (B)

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146. Corrosion resistance of steel is increased by the addition of

1. Phosphorous and tungsten
2. Nickel and chromium
3. Lead and vanadium
4. Molybdenum and tungsten

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147. Corrosion resisting properties of cast iron are significantly improved by the addition of 12 - 15% of

1. Tungsten
2. Vanadium
3. Silicon
4. All (A), (B) & (C)

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148. Creep is not exhibited at low temperature by

1. Rubber
2. Acrylics
3. Lead
4. Plastics

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149. DDT is shipped in

1. Stainless steel containers
2. Paper bags
3. Fibre drums
4. Either (B) or (C)

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150. Dead mild steel, which contains 0.10 to 0.15 percent carbon is used for making

1. Shafts
2. Flanges
3. Gears
4. Shear blades

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