Which of the following is a solid fuel?
Wood
Solid fuels: These are fuels that exist in the solid state at room temperature.
Examples- Wood and Coal
Liquid fuels: These are fuels that exist in the liquid state at room temperature.
Examples- petroleum fuels like petrol, diesel and kerosene.
Gaseous fuels: These are fuels that exist in the gas state at room temperature.
Examples- LPG (Liquefied petroleum gas) and CNG (Compressed natural gas)