263. For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm³) while the C.V. is same on weight basis (i.e., kcal/kg) ? September 6, 2025 by Admin A. Propane and acetylene B. Propane and LPG C. Sewage gas and gobar gas D. B.F gas and coke oven gas ✅ The correct answer is option D.