2145. The softest material just next to talc in the Mho’s scale is
Quartz
Gypsum
Feldspar
Fluorite
✅ The correct answer is option B.
2148. Glass lined vessels are not used for handling/storing
Dilute H₂SO₄
Dilute HNO₃
Dilute HCl
Hydroflouric acid
✅ The correct answer is option D.
2151. Addition of nickel to copper improves its
Machinability
Ductility
Strength
Hardness
✅ The correct answer is option D.
2157. Babbit metal (used for making bearings) comprises of
Mainly tin (85%) and lead
Saw dust and iron dust mixture
Zinc and aluminium
Copper and aluminium
✅ The correct answer is option A.
2160. __________ is a donor impurity for semi-conductors.
Boron
Antimony
Gallium
None of these
✅ The correct answer is option B.
2163. Pick the odd man out of the following.
Calorising
Pack carburising
Nitriding
Cyaniding
✅ The correct answer is option A.
2166. Iron alloyed with carbon upto 2% is called
Pig iron
Wrought iron
High carbon steel
None of these
✅ The correct answer is option D.
2168. Steel tower used for the storage of oleum
Is lined with lead
Need not be lined
Is lined with rubber
Is lined with acid-proof bricks
✅ The correct answer is option B.
2170. To improve the machinability of steel by its softening, it is subjected to
Cold working
Annealing
Shot blasting
Heating
✅ The correct answer is option B.