3390. Initial pressure of oxygen introduced into the ‘bomb’ of the bomb calorimeter for determination of calorific value of coal/fuel oil may be around __________ atm.
3-May
25-30
60-65
95-100
✅ The correct answer is option B.
3396. Which of the following is a primary fuel?
Blast furnace coke
Gasoline
Natural gas
Wood charcoal
✅ The correct answer is option C.
3401. A good coking coal should have high __________ content.
Ash
Sulphur & phosphorus
Moisture
None of these
✅ The correct answer is option D.
3408. Main constituent of natural gas is
CH₄ (upto 90%)
C₂H₆
C₃H₈
H₂
✅ The correct answer is option A.
3356. Which of the following impurities reduces the refractoriness of magnesite bricks ?
Al2O3
CaO
SiO2
all (a), (b) & (c)
✅ The correct answer is option D.
3361. Carborundum used for making crucibles for melting non-ferrous metals is chemically
silicon carbide
silicon nitride
crystalline magnesia
zirconium sulphate
✅ The correct answer is option A.
3366. Which of the following has the lowest electrical resistivity ?
Graphite
Fireclay
Alumina
Zircon
✅ The correct answer is option A.
3333. Chrome magnesite bricks are
acidic in nature.
neutral in nature.
having higher RUL than silica bricks.
made by mixing 30% chromite and 70% periclase.
✅ The correct answer is option C.
3338. Firing temperature is minimum (1250-1400 °C) for __________ bricks.
fireclay
direct bonded basic
silica
magnesite
✅ The correct answer is option A.
3339. Silica bricks are never used for lining the
beehive coke ovens.
by-product coke ovens.
dome of blast furnace stoves.
roof of open hearth furnace.
✅ The correct answer is option A.