101. The optimum percentage of excess air for combustion depends upon the __________ of the fuel. September 7, 2025 by Admin Type (solid, liquid or gaseous) Calorific value Sulphur content Ignition temperature ✅ The correct answer is option A.
102. Cannel coal September 7, 2025 by Admin Is non-coking Has a high volatile matter content and burns with a luminous smoky flame Is a non-banded coal which can be ignited easily with a match stick or candle flame, hence is so named All of the above ✅ The correct answer is option D.
103. A sooty flame can be made non-luminous by September 7, 2025 by Admin Admitting more gas Shutting gas supply Admitting more air Shutting air supply ✅ The correct answer is option C.
104. Which of the following constituents of a fuel does not contribute to its calorific value on combustion? September 7, 2025 by Admin Hydrogen Sulphur Carbon None of these ✅ The correct answer is option D.
105. Which of the following is the most reactive (as regards the formation of CO + H₂ from C + H₂O) ? September 7, 2025 by Admin Blast furnace coke Low temperature coke Anthracite coal Sub-bituminous coal ✅ The correct answer is option B.
106. A coal containing very high percentage of durain is called __________ coal. September 7, 2025 by Admin Bright Splint Non-banded Boghead ✅ The correct answer is option B.
107. Very __________ coals are completely devoid of cokability i.e, it is non coking. September 7, 2025 by Admin Young Mature Both A & B Neither A nor B ✅ The correct answer is option C.
108. Gobar gas constitutes mainly of September 7, 2025 by Admin CH₄ & CO₂ CO & CO₂ CH₄ & N₂ CO & N₂ ✅ The correct answer is option A.
109. Gray-King Assay and Roga Index of coal is a measure of its September 7, 2025 by Admin Abradability Grindability Weathering properties Caking and swelling properties ✅ The correct answer is option D.
110. In general, the limit of inflammability/explosion limit of fuel gases is widened by the September 7, 2025 by Admin Increase in gas pressure Increase in temperature (i.e. preheating) Use of pure oxygen for combustion instead of air All of the above ✅ The correct answer is option D.