FuelThese are the substances that form source of energy. They exists as Solids, Liquids, and Gases. A good fuel is one which is readily available. It is cheap. It burns easily in air at a moderate rate. It produces a large amount of heat. It does not leave behind any undesirable substances.
Example : Wood, charcoal, petrol, Kerosene, etc.
Coal is a Solid Fuel
Diesel is a Liquid Fuel
Car using C.N.G
Fuel efficiency is measured as the amount of heat produced by burning 1 Kg of fuel known as the calorific value of the fuel .It is expressed in a unit called kilojoules per Kg.
Consider the calorific values of the fuels as given in the table and classify them as solid, liquid and gaseous fuels and arrange the fuels in the decreasing order of their fuel efficiency.
|Calorific Values of Different Fuels Fuel Calorific Value||
|Cow dung cake||6000-8000|
Classify the fuels as solids, liquids and gases.
Global warming is an undesirable phenomenon caused as the result of burning of Carbon fuels like wood, coal, petroleum release carbon dioxide gas responsible for trapping infrared radiation from sun and not allowing it to escape from the surface of the earth, the presence of excess heat energy radiation that is infra red radiation increases surface temperature of the earth resulting in global warming. The impact of global warming is the melting of polar glaciers, which leads to a rise in the sea level,Causing floods in the coastal areas.
Melting of Glacier
Acid rain is formed when acidic gases such as sulphur dioxide and oxides of nitrogen liberated as pollutants from industries dissolve in rain water.
Acid Rain Formation
Acid rain is very harmful to plants and old monuments.
Trees being destroyed by acid rain
Acid rain destroys the beauty of monuments like Taj Mahal