The primary sources of energy are the sources of energy that are used in the same form as they are available in nature.

The type of energy sources that get depleted and cannot be replaced quickly when exhausted are called non-renewable sources of energy. Any 2 examples are:

1. Fossil fuel
2. Natural gas

The energy sources that are continuously produced in nature and are inexhaustible are called renewable sources of energy. Some examples are:

1. Solar energy
2. Tidal energy

As we know that the sun provides both heat and light energy for all living beings. It is the main source of energy as it supplies energy for all organisms directly or indirectly. It is the storehouse of energy. It also supports the existence of other sources of energy like fossils, solar energy, hydroelectricity, bio-fuel, and so on. So, we can say that all the energy sources are the outcome of solar energy. So, the sun is the main source of energy.

Any three conditions required for the thermonuclear fusion reaction in the sun are:

1. In the sun, there is a sufficient amount of hydrogen gas.
2. There is a very high temperature in the sun which is essential for the formation of free protons.
3. There is necessary pressure for the combination of free protons.

The fuel formed from the fossils of plants and animals buried under the earth's crust for a long time is called fossil fuel. Any two examples are:

1. Coal
2. Petroleum products

The liquid formed of fossil fuels such as petrol, diesel, and so on is called mineral oil. Any three advantages are:

1. It is cheaper for long-term production.
2. It can be easily transported.
3. It can be used to generate electricity.

Any two reasons for the statement 'hydropower is better than fossil fuel.' are:

1. Hydropower is a renewable source but fossil fuel is non-renewable.
2. Hydropower is eco-friendly but fossil fuel pollutes the environment.

Any three advantages of hydropower are:

1. It is a renewable source of energy.
2. It is eco-friendly.
3. It is cheaper in the long-term.

The source of energy that can be used to reduce the negative impact of non-renewable sources of energy replacing these sources is called an alternative source of energy. Its examples are:

1. Biofuel
2. Nuclear energy

We all know, Nepal is an agricultural country. Naturalwastes, sewage, etc. can be used to generatebiofuel. The most practiced profession animal husbandry is also the source of different materials likedecayed grasses, dung, etc which again can be usedto get biofuel. On the other hand, a lot of denseforests are found in Nepal from where a high amountof biofuel can be taken. So, in the context ofNepal, biogas energy is the best source ofalternative energy.

The heatenergyobtained from the hot rocks this is present inside the earth is called geothermal energy.

In the place where earthquakes and volcanoes are active,the temperature increases highly in comparison to normal.The hot underground water can be brought to thesurface, fill the hole, and covered by earth. Two holes aremade in the upper surface. In one of them, cold watergoes inside, and in another hotvapor comes out.

This hot water vapor is used to run the steamengine rotating turbine to...

Scientists arebusy making equipment based onsolar energy because solar energy istaken as themost important and effective alternative source ofenergy as it isavailable in every part of the earth anddoesn't haveany negative effects on the environment.The light energy from the sun is converted into electrical energywith the help of photoelectric cells. The converted electricenergy can be used again to get heat, light, etc.without having any deterioration to the environment.

So, it is the best...

The acute scarcity of energy sources due tooveruse or exploitation by the growing population iscalled anenergy crisis.Any 3 ways to solve it are:

1. Adaption of alternativeenergy sources.
2. Banning the use of non-renewable sources and encouraging the use of renewable sources.
3. Using existing sources wisely and economically.

The meaning of E = mc² is when a body is movingat the speed of light, the energy produced would beequal to the product of mass that the body losesand the speed of light.

Here, E =Energy produced,
m = mass defect, and
c = velocity (speed) of light.

The scientist who profounded the equation wasAlbert Einstein.

The power generated by rotating turbines using water iscalled hydropower. It is the main source of energy which isa pollution-free and renewable source of energy.Energy trapped in the flowing river is used to generatepower on large scale in power stations which a cheaperfor thelong term & widely cued in electric devices. Butpetroleum products are temporary. They are only for ashort period of time. These products are formed fromthe dead remains of plants and animals that includemineral...

We all know, coal and petrol are obtained from the earth'scrust that is deposited under the earth's crust frommillions of years ago. These resources are limited in natureand get depleted aftera single-use. It cannot beproduced time and often. So, it is called a non-renewableenergy source.

We all know, biofuel is the organic source of energy thatcan be obtained from biomass, wood, hay, straw, etc. It is more eco-friendly than other sources. It also can beproduced continuously and effectivelyeven inrural areas. So, it is called a renewable energy source.

We all know, fossil fuel formed from the fossils ofthe plants and animals that are buried under theearth's crust. It is cheaper as it is found in a huge amount.It is easier to transport this fuel It is used forvarious purposes like to run automobiles, factories, andeven to generate electricity. So, fossil fuel is usedmore than other fuels in the world.

We all know the sun is the main source of energy. It is an extremely large mass of hot gasses. It provides energyfor all living beings on the earth directly or indirectly. It is the storehouse of energy. Itproduces energy called solar energy. Hence, the sun isthe ultimate some of energy.

a.Renewable and son sewable source of energy.

b. Nuclear fission and nuclear fusion.

We all know, Nepal is a countrythat is rich enoughin water resources. Hundreds of fast-flowing riversare found in our country. And water is the mainagent to produce hydroelectricity. Due to the presence ofmany large and small rivers & rivulets, we have thehigh potentiality of generating electricity. But itisverydifficult to construct hydropower stationsin the various parts of the country because of the difficulttopography. The absence of infrastructuralfacilities isthe major cause of it....

The energy present in the body of a dead person doesn't escape instantly but stays in the body.

Later when the body is buried, it decays and the energy is released to the soil. If the body is burnt instead, the energy is released to atmosphere.This is a part of carbon cycle.

Energy is defined as the capacity to do work. It can neither be created nor destroyed, but it can be transformed from one form to another.