Flame is the zone of combustion of a combustible substance. Substances which vapourise during burning produce flames.
Eg:- kerosene, wax,oils etc.
Substances which do not vapourise during burning do not produce flames.
Eg:- coal, charcoal etc.
The colour of the flame depends on the temperature, amount of air available, and the nature of the substance burning. Hydrocarbons burn with blue or yellow flame depending upon the amount of oxygen available.
The essential conditions for a combustion are: Fuel, air (to supply oxygen) and heat (to raise the temperature of the fuel beyond the ignition temperature).
Fire can be controlled by removing one or more of these requirements.
Fuels serve as a major part of our energy requirement. They are the concentrated store of energy, which is released as heat when fuels are burnt.
Fuels are combustible substances of organic origin or artificially obtained substances, which are used for producing heat and energy. Wood, diesel, coal .domestic gas, petrol and biogas are some of the examples of fuels.
Fuels play an important role in our everyday life because they are used in homes, transport and industry for providing energy.
For domestic use:
Fuels like wood, coal, kerosene, domestic gas, cow dung etc. are used in our homes for cooking.
