Fuels and Combustion The optimum percentage of excess air for combustion depends upon the __________ of the fuel. Type (solid, liquid or gaseous) Ignition temperature Sulphur content Calorific value Type (solid, liquid or gaseous) Ignition temperature Sulphur content Calorific value ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion The ratio of % total carbon obtained in the ultimate analysis of coke and % fixed carbon obtained in the proximate analysis is always Unpredictable < 1 1 > 1 Unpredictable < 1 1 > 1 ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion Rate of low temperature oxidation of coal due to bad storage conditions Is more for low volatile coal compared to high volatile coal Is accelerated by storage in large heaps with small surface to volume ratio Decreases with increase in surface area Does not vary with increase in surface area Is more for low volatile coal compared to high volatile coal Is accelerated by storage in large heaps with small surface to volume ratio Decreases with increase in surface area Does not vary with increase in surface area ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion The internal energy of the combustion products is __________ compared to that of reactants. Less Equal More More or less ; (depends on the state of fuel.) Less Equal More More or less ; (depends on the state of fuel.) ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion Prime coking coal is always blended with medium or non- coking coal before ear-bonisation Both A & B Because, it alone produces unreactive coke To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls Neither A nor B Both A & B Because, it alone produces unreactive coke To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls Neither A nor B ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion Ash content in the middling coal (a byproduct of coal washeries) in India ranges between __________ percent. 55 to 75 75 15 to 25 35 to 45 55 to 75 75 15 to 25 35 to 45 ANSWER DOWNLOAD EXAMIANS APP
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