Question

Why do we need to burn a large quantity of wood for cooking food?

Answer 1

1. Wood is still used as a fuel to cook food in small open furnaces called chulhas and also in industrial boilers.
2. Wood when used as a fuel is called firewood.
3. The calorific unit of wood is very low, being only 17 kJ/g.
4. As a result, when burned, it produces very little energy.
5. So, for a fuel that has a higher calorific value less amount would be burnt compared to wood.