421. Mott and Wheeler test is conducted on coke to find its Reactivity with O₂ Abradability Phosphorus content Volatile matter content ✅ The correct answer is option A.
422. High sulphur content in a fuel __________ of the flue gases. Decreases the dew point Increases the dew point Reduces the combustion efficiency by limiting the permissible temperature reduction Both B & C ✅ The correct answer is option D.
423. The pyragallol solution used in orsat apparatus can absorb Only O₂ Both O₂ and CO₂ Both O₂ and CO All of the above ✅ The correct answer is option B.
424. Calorific value of a typical dry anthracite coal may be around __________ Kcal/kg. 1000 4000 8000 15000 ✅ The correct answer is option C.
425. Natural draught produced by a chimney depends upon the Density of the chimney gases Height of the chimney Both A & B Neither A nor B ✅ The correct answer is option C.
426. Which of the following is not endothermic? Cracking Reforming Gasification Partial oxidation ✅ The correct answer is option D.
427. In high temperature carbonisation of coal compared to low temperature carbonisation Yield of ammonia is less Aromatic content of tar is low H₂ content in the coke oven gas is more Calorific value of the coke oven gas is lower ✅ The correct answer is option C.
428. Calorific value of dry wood may be around __________ Kcal/kg. 5 50 500 5000 ✅ The correct answer is option A.
429. Fuel consumption in coke making can be reduced by Preheating, blending and de-ashing the coal Stamped charging of coal Dry quenching of coke All of the above ✅ The correct answer is option D.
430. Which of the following is not a binder for coal briquetting? Coal tar Bitumen Molasses None of these ✅ The correct answer is option D.