Topic - 10 Sources of energy Topic-Sources of energy Sub-Science Std-8th Topic - 10 Sources of energy Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Introduction 10.1Fossil fuel 10.2 Forms of fossil fuel 10.3 Sun 10.4 Solar cooker & Solar heater 10.5The solar cell 10.6 Other sources of energy 10.7Atomic energy Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy The capacity to do work is called energy. Although energy has many forms ,it can be changed from one form into another. Std-8th Sub-Science Topic-Sources of energy

A substance that produced energy on burning is called fuel. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy FOSSIL FUEL A lakes of years ago because of different calamities ,remnants of plants and animals got buried into the earth. Due to effect of the tremendous pressure of layer of the earth above the heat inside they were converted into fuel. Such fuels are called fossil fuel Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Forms of fossil fuel- Fossil Fuel Solid Liquid Gaseous Std-8th Sub-Science Topic-Sources of energy

1.SOLID It was made from remains of plants. Firewood and brushwood are used in rural areas. Charcoal is formed when wood is burnt in insufficient air. Charcoal burns smoke less. Std-8th Sub-Science Topic-Sources of energy

2.LIQUID Mineral oil is found nearly 25,000 meters deep in the bowels of the earth. Petrol, diesel, kerosene and fuel oil can be obtained from it . 70 percent mineral oil we use. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy 3. GASEOUS Natural gas is lights up quickly and burns without leaving behind any solid substances. Besides, it is easy to transport form its main source by means of pipes over long distances. A big advantage is that the burning of natural gas can be easily controlled. Ex. methane [CH4], ethane[C2H6], propane[C3H8], butane[C4H10], etc. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Sun The earth gets a tremendous amount of energy from the sun as much as 7 x 1017 kilowatts per year. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Solar Cooker Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Solar Heater Std-8th Sub-Science Topic-Sources of energy

Solar cooker and solar heater Topic-Sources of energy In this devices, mirrors are used to collect and concentrate solar energy. It can be used to cook food or heat water, etc. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Solar Cell Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Solar cell In the solar cell, solar energy is converted into electric energy and this can be used at night for lighting. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Fossil fuel They cannot be produced a new, therefore, they are called to be conventional or non- renewable sources of energy. There are only limited deposits of fossil fuel. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Solar energy It is always available, so they are called non-conventional or renewable source of energy. Std-8th Sub-Science Topic-Sources of energy

Other sources of energy Wind energy, hydro- electric energy, biogas, bio-diesel Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Wind Energy Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Biogas Std-8th Sub-Science Topic-Sources of energy

Problem created by using conventional sources of energy Global warming – Gases like carbon-dioxide, carbon-monoxide, hydrogen sulphide causes problem of population. Pollution – Carbon-dioxide and many other gases causes problem of pollution. Deplenation of ozone layer- gases like CFC causes holes in ozone layer of atmosphere. Deforestation-Due to cutting trees causes number of forest become dwindled. Std-8th Sub-Science Topic-Sources of energy

Topic-Sources of energy Atomic energy Std-8th Sub-Science Topic-Sources of energy

Questaion 1 What is mean by Fuel 3 Name of the solar apparatas 2 Name the different types of fossil fuels. 3 Name of the solar apparatas 4 What is mean by Enerngy

Name - Mrs.Patil shashikala Chandrakant School Name :-Chh.shivaji vidyalay ,palaspe tel:Panvel Dist :- Raigad Std ;-8th sub -Science