These DAV Class 5 Science Notes and DAV Class 5 Science Chapter 9 Notes – Fuels act as excellent revision resources, particularly in preparation for board exams.
Fuels Class 5 DAV Notes
→ Fuel: A substance that produces energy on burning is called fuel.
Types Of Fuels:
(a) Solid fuels: Wood, coal, coke, cowdung cakes, etc.
(b) Liquid fuels: Kerosene, petrol, diesel, etc.
(c) Gaseous fuels: Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), Piped Natural Gas (PNG) and biogas
→ Uses of Fuels: Energy is required for many purposes. We need energy for cooking, for moving trains, automobiles and aeroplanes. We need energy for generating electricity and for running machines. For all these purposes, we use different types of fuels.
- Firewood was the only fuel for early man. Firewood is still used in rural areas as kitchen fuel.
Cowdung cakes, coal and kerosene are also used; mainly in rural areas.
- Now-a-days, most of the modem households use LPG and PNG as kitchen fuel. Biogas is also used both in urban and rural areas.
- Gaseous fuels are much cleaner than solid or liquid fuels. They do not leave any ash after burning and do not produce smoke.
Fuels For Transportation:
- Earlier, steam engine was used in trains. Steam was produced by heating water on burning coal.
- Now-a-days, trains are run by using diesel engines and electric engines.
- Vehicles use diesel and petrol as fuel. The big vehicles use diesel, while petrol is the main fuel in small vehicles.
- However, some cars also use diesel.
- Now, CNG is being increasingly used in many cities in India. CNG is much cleaner and is eco-friendly.
Fuels For Generating Electricity:
→ Coal is the main source of energy in thermal power plants. In these plants, coal is burnt to convert water into steam. The steam is used to mn turbines which generate electricity.
→ Method of generating electricity in thermal power plants is not eco-friendly. Gradually, better and eco-friendly methods are being used for electricity generation.
Fuels And Machines:
- Earlier, most of the work was done manually, i.e. by hand.
- Then, hand-operated machines were made. Working with machines helps in saving time and improves productivity.
- Hand-operated machines were later replaced by steam powered machines. Gradually, steam engines were replaced with diesel engines and electric engines. This further helped in improving production in factories.
→ Coal and petroleum are fossil fuels.
They are called fossil fuels because they were formed by decomposition of animal and plant matter. Millions of years ago, animals and plants got buried under the surface of earth. Under heat and high pressure, over a long period of time, they got changed into coal and petroleum.
→ Coal: It is sedimentary rock. It is combustible which means it can bum. It is black in colour. Coal is the primary source of energy for producing heat and electricity.
→ Petroleum: Crude oil is called petroleum. It was formed from dead sea creatures which got buried under the earth.
→ Natural Gas: Natural gas is often found from the oil wells.
→ Fuel: A substance which produces energy on burning.
→ Fossil fuel: Coal and petroleum are called fossil fuels because they were formed from fossils.
→ LPG: Liquefied Petroleum Gas
→ CNG: Compressed Natural Gas
→ PNG: Piped Natural Gas
→ Biomass: Waste matter of animals and plants.
→ Non-renewable Resource: A resource which cannot be readily replenished after use.
→ Renewable Resource: A resource which can be readily replenished after use.