40 TOP Fuels and Combustion Online Test – Multiple Choice Questions and Answers 1. Yield of pitch from distillation of high temperature tar is around __________ percent 10 25 65 100 2. The heat of combustion of a fuel is always positive can’t be known without calculating it is always negative is equal to the heat of formation 3. ‘Fat’ coal means a coal having low ash content low calorific value high volatile matter non smoking tendency 4. __________ has the widest inflammability limit (explosion limit) of all the gases Methane Acetylene Hydrogen Carbon monoxide 5. Proximate analysis of coal determines its __________ content moisture, sulphur, nitrogen & fixed carbon moisture, ash, sulphur & volatile matter moisture, volatile matter, ash & fixed carbon none of these 6. “Overfire burning” in a furnace is a phenomenon characterised by the supply of excess air burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air supply of excess fuel none of these 7. With increase in moisture content of coal, its clinkering tendency during combustion increases calorific value increases sometimes bulk density always decreases none of these 8. In flue gas analysis by Orsat’s apparatus, carbon dioxide is absorbed by potassium hydroxide dilute potassium carbonate alkaline pyragllol solution cuporus chloride 9. Abrasion index of blast furnace coke should be around __________ percent 20 35 55 80 10. Which of the following petrographic constituents of coal is non-coking ? Clarain Fussain Vitrain Durain Loading … Question 1 of 10
