CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES. Energy supply is the delivery of fuels or fuels transformed to the point of consumption. It potentially encompasses the extraction, transmission, generation, distribution and storage of fuels. It is also sometimes called energy flow. CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES.

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES
CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES. This energy supply can be disrupted by various factors, including the imposition of higher energy prices due to action by OPEC or another cartel, war, political disputes, economic disputes, or physical damage to energy infrastructure due to terrorism. The security of energy supply is one of the main concerns of energy legislation and national security. CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES.

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES
CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES

CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES. Some sources refer to “energy supply” when in fact they refer to oil reserves or other potential sources of energy. New York Statutes include a statutory code called the “Energy Law.” Article 21 of this code is called “Energy supply and production”, but instead of a complete code, it only consists of a section dealing with renewable energy. CLASS 9th SCIENCE NOTES CHAPTER 5 ENERGY SOURCES.

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UNIT:5

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Q.1: What would happen if there was no electricity?

Ans: If there was no electricity factories, offices, communication and fast transportation will shut down. The machinery will stop working. No electricity will put a huge burden on other sources of energy. People will have to use old methods of communication. No electricity will stop the fast progress of the world.

Q.2: What is overuse of electricity?

Ans: Over use of electricity means wasting a valuable source of energy. It is to use electricity unwisely. It is the misuse of electricity. To keep lights, fans, TVs and ACs on when they are not needed. It is wasteful use these things.

Q.3: What are the advantages and disadvantages of using petroleum?

Ans: Advantages of petroleum:

Petroleum is a source of power generation. It is easy to extract at a low cost. It is used in almost every machine like cars, buses and generators. It can be transported easily. It can be applied almost everywhere. It is the main element of industry. It can power up many machines.

Disadvantages of petroleum:

Petroleum resources are very limited. It is a non-renewable source of energy. It can catch fire easily. It causes environmental pollution. Production and refining of petroleum produces harmful and toxic materials. Its spills cause the death of animals and fishes. If oil money goes into wrong hands it results in terrorism.

Q.4: Give two examples of ways to conserve energy at home.

Ans: We must put off all the electrical objects, when we do not need them. We shall use those electrical appliances that need minimum energy like energy savors and tube lights instead of bulbs. Our homes should get maximum solar energy and fresh air.

Q.5: What is the conventional source of energy?

Ans: Conventional energy means the energy source which is fixed in nature like oil, gas, coal and firewood. It is also termed as non-renewable energy sources. Their use increases the greenhouse effect and other environmental damages.

Q.6: What is the importance of conserving energy?

Ans: Conserving energy is very important because the earth is short of energy resources. It lessens the burden upon the present energy resources. It reduces the greenhouse effect and global warming. It improves our health and economy. Conservation lessens climate change. It replaces non-renewable resources with renewable energy. It is an easy solution to energy shortage and more energy production. It preserves energy for our future generations.

Q.8: Describe various types of fossil fuels?

Ans: Fossil fuels:

Fossil fuels are formed by the decomposition of dead organisms over a period of millions of years. They are easy to use. Coal, petrol and natural gas are some important sources of fossil fuels. Each different type of fossil fuel occurs in a different chemical state

Coal:

Coal is used for everything from producing steel and cement to keeping the lights on in homes and business. Coal is in solid state. About 40% of electricity worldwide is generated with the help of coal. It is the main element of industries. One fourth of the total energy used worldwide is taken from coal.

Petroleum:

Petroleum or crude oil is the most used fossil fuel round the world. Due to its value to mankind it is known as black gold. Petroleum is mainly used to fuel jet and automobiles. It is also used to generate electricity to run our industries to produce different products. Its resources are decreasing day by day. Its overuse has contributed to water and air pollution.

Natural Gas:

It is a major energy source. Its major consumers are the residential, commercial and industrial sectors. It is also used to generate electricity. Unlike other fossil fuels, natural gas is cleaner and causes less pollution. Like other fossil fuels, this resource is depleting rapidly. Natural gas is odorless when it is mined from beneath the Earth’s surface. The smell is added later to alert people about the leaks of the substance.

Q.10: Write in detail the nature and utility of any two non-conventional sources of energy.

Ans: Non-conventional sources of energy are environment friendly and inexhaustible. The two non-conventional sources of energy are wind and solar energy.

Solar Energy:

The amount of energy that we get from the sun is called solar energy. Solar energy is in abundance of all non-conventional sources but its usage amount is very less. We use solar energy directly or indirectly.

Uses of Solar energy:

Solar energy is used to cook food. It helps in preventing deforestation. It improves our financial resources. Solar energy is used to heat water instead of using gas or electricity.

Solar cells use solar power to generate electricity from the sun.

In photosynthesis, green plants absorb solar energy and convert it into chemical energy. It gives non-polluting environment-friendly output.

Wind energy:

Wind energy is the process by which wind is used to generate energy. As the wind increases, power output increases. Wind farms prefer areas, where winds are stronger and constant. These are generally located at high altitudes.

Uses of wind energy:

Wind is used to make electricity. There is no pollution because no fossil fuels are burnt to generate electricity. It is used to grind grains and sail boats. It can also pump water from wells.

Q.11: Compare renewable energy sources with nonrenewable sources. Or

Q.12: Differentiate between conventional energy sources and nonconventional energy sources.

Ans: Non-conventional sources:

They are also called Renewable sources. Sun, water, and wind are their examples.

They are non-conventional sources of energy.

They are easy to locate.

It is not very easy to generate energy from them.

They do not pollute the environment.

They are inexhaustible.

Their price remains the same.

They are available almost everywhere.

They are not extracted from the earth.

In most cases not suitable for large scale power generation

They are not fully developed.

They don’t need combustion to produce energy.

Conventional sources:

They are also called Non-renewable sources. Gas, coal, and petrol, are their examples.

They are conventional sources of energy.

Effort is required to get them.

It is very easy to generate energy from them.

They increase greenhouse effect and global warming.

Their sources are limited.

Their price goes up and down.

They are not available everywhere.

They are extracted from the earth.

They produce energy on a very large scale.

They are fully developed.

Generally they produce energy after combustion.

Q.13: Briefly write the process of formation of fossil fuel.

Ans: Fossils are formed in a number of different ways, but most fossils are formed when a plant or animal dies in a watery environment and is buried in mud and silt. Soft tissues quickly decompose leaving the hard bones or shells behind. This decomposition takes place in the absence of oxygen. Over time pressure from the silt layers builds over the top and compressed the organic material and forms fossil fuels.

Q.14: Describe the role of energy in the development of a country.

Ans; Energy plays a major role in the development of a country. Wealth, health, nutrition, water, infrastructure, education, even life expectancy itself, are related to the consumption of energy.

Education: A country having rich in energy sources will provide quality education to its people. It will have qualified persons and institutes. A country poor in energy sources will not be able to give proper education to its talented people.

Health: The more a person takes and consumes energy, the more fit and strong he is. Low sources of energy create a bad effect on the health of people.

Food: Quality and quantity of food depends on energy. If a country is rich in energy sources, its people will get a balanced diet. If a country lacks energy sources its people will have a poor diet.

Water: Water is the essence of life. Pure and clean water gives sound health. Sources of water irrigate fields. They create electricity and run our machinery. A country with no or limited water sources will depend on other sources of energy.

Wealth: Sources of energy enable a country to increase the wealth of its people. There are a number of ways to improve economy.

Infrastructure: Sources of energy strengthen the infrastructure of a country. If all the basic needs are provided, a country makes progress. Lacking in sources of energy, badly affect the infrastructure and slows down the progress.

Life expectancy: A country having many energy sources will provide quality health facilities to its people. It will increase life expectancy in that country. Low energy sources will lead to rapid deaths and diseases.

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