3195. Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
mortars
cements
castables
none of these
✅ The correct answer is option C.
3200. Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage ?
Tar bonded dolomite bricks
Fireclay bricks
Mullite bricks
Magnesite bricks
✅ The correct answer is option A.
3205. Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
10
15
20
30
✅ The correct answer is option D.
3210. Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
2-Mar
5-Jul
7-Dec
14-20
✅ The correct answer is option D.
3215. Which one expands on heating ?
Silica bricks
Fireclay bricks
Both (a) & (b)
Neither (a) nor (b)
✅ The correct answer is option A.
3155. Which of the following is a lean fuel gas?
Coke oven gas
LPG
Blast furnace gas
Natural gas
✅ The correct answer is option C.
3160. Main constituents of benzol are
Benzene, toluene & xylene
Tar & creosote
Ammonia & phenol
Anthracene & phenol
✅ The correct answer is option A.
3165. During coking of coal, the ash content (percentage)
Increases
Decreases
Remains constant
None of these
✅ The correct answer is option A.
3170. The sequence of absorption in flue gas analysis by Orsat’s apparatus is respectively
CO₂, O₂, CO
CO, O₂, CO₂
CO₂, CO, O₂
O₂, CO₂, CO
✅ The correct answer is option A.
3175. When incomplete combustion loss is high, the flue gas analysis shows large amount of
CO₂
CO
O₂
C
✅ The correct answer is option B.