2118. Brinell Hardness Number (BHN) for talc is approximately in the range of
1-May
20-30
100 -150
200 – 250
✅ The correct answer is option B.
2121. High resistance electrical heating elements/wire are not made of
Marageing steel
Nimonic alloys
Kanthal wire
Nichrome
✅ The correct answer is option A.
2124. Lead pipes are not safe for carraying drinking water, because water, containing dissolved oxygen attacks lead thereby forming poisonous Pb(OH)₂. Lead pipes are readily corroded by
Dilute HC₁
Acetic acid
v
None of these
✅ The correct answer is option B.
2127. Gunmetal and bronze are not corroded by the action of
Wet chlorine
Synthetic detergent solution
Hydrochloric acid (10%)
Nitric acid (< 25%)
✅ The correct answer is option B.
2130. Brine (15% concentration) can be stored in a vessel made of
Monel
Karbate
Cast iron
None of these
✅ The correct answer is option A.
2133. Carbon percentage in medium carbon steel is around
0.1 to 0.35
0.35 to 0.5
0.8 to 1.4
1 to 1. 5
✅ The correct answer is option B.
2136. Steel will respond to hardening by heat treatment processes, only when the minimum carbon content in it is __________ percent.
0.02
0.2
0.35
0.5
✅ The correct answer is option B.
2139. The increase in hardness of metal due to its cold working is termed as the __________ hardening.
Work
Age
Induction
Flame
✅ The correct answer is option A.
2142. Lead pipes are not safe for carrying drinking water because water containing dissolved oxygen attacks lead thereby forming poisonous Pb (OH)2. Lead pipes are readily corroded by
Dilute HCI
Acetic acid
Concentrated H₂SO₄
None of these
✅ The correct answer is option B.
2102. The metals occuring at the lower most position in the electromotive series
Do not resist corrosion
Resist corrosion very strongly
Are very brittle
Are heat insulators
✅ The correct answer is option B.