451. Approximate value of the modulus of elasticity for steel is about __________ x l0⁶kg/cm².
0.5
2
40
75
✅ The correct answer is option B.
Materials and Construction MCQs
452. Maximum consumption of lead is in the manufacture of
Storage batteries
Solder alloys
Electric cable sheathing
Lead lined vessels
✅ The correct answer is option A.
453. Presence of even 0.005% of __________ in copper makes it highly brittle, rendering it useless for wire-drawing.
Oxygen
Arsenic
Antimony
Bismuth
✅ The correct answer is option D.
454. Presence of even very minute amount (say 0.1%) of __________ in copper, reduces its electrical conductivity very seriously.
Bismuth
Arsenic
Antimony
Both B and C
✅ The correct answer is option D.
455. 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.
456. Iron alloyed with carbon upto 2% is called
Pig iron
Wrought iron
High carbon steel
None of these
✅ The correct answer is option D.
457. Rubber lined vessels are corroded by the action of
Aqua regia
Chloroform
Sulphuric acid (95%)
All of the above
✅ The correct answer is option D.
458. 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.
459. The chlorinator used in the manufacture of DDT is made of
Glass
Glass lined steel
Teflon
Bakelite
✅ The correct answer is option B.
460. 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.