chapter - natural resources

PART - A

Q1: what are non - renewable resources? Give two examples.

Ans : the resources which cannot renewed by natural processes are called non - renewable resources

For eg. Coal, petroleum and natural gas.

 

Q2: why is it said that plantations cannot make up for loss of primary forests?

Ans: because man made forest Cannot fully complete the loss of primary forests. man made forest do not have many types of organisms that primary forests have.

Q3: what are natural causes of deforestation?

Ans:1.  Droughts

2. Floods

3. Storms

4. Forest fire

Q4: mention some human activities that cause deforestation?

Ans:1 production of paper

 2  Shifting cultivation

3  Making of furnitures

4  Making of factories

5  Making of roadways

Q5: how do forest protect the soil?

Ans: the cover of leaves protect the soil from the direct contact of rain and the root keep the soil in place.

Q6: mention the consequences of deforestation.

Ans: it leads to

1 Soil erosion

2 Floods

3 Droughts

4 Climate change

Q7: why are coal ,petroleum and natural gas called the fossil fuels?

Ans: because I was formed by the fossilization of plants and animals remains.

Q8 : what do you understand by the commercial energy?

Ans: the energy that can be sold bought

 but it is not produced by cattle dung etc.

for example electrical energy.

Q9: name the products formed by destructive distillation digestion of court. What is a annonical liquid used for?

Ans: the products are

1Coal gas

2Coal tar

3Coke

4Ammonical liquor

Ammonical liquor is the used for the production of fertilizers.

Q10: name some alternative sources of energy that we can use for generation of electricity.

Ans: wind energy

Solar energy

Ocean energy

Hydroelectricity

PART-B

 

Q1: what measures can we take to bring down the number of trees felled annually for production of paper?

Ans: we should not waste the paper.

We should recycle the paper.

We should use cloth handkerchief we should not use napkin paper.

Q2: what impact does deforestation have on climate?

Ans:1 deforestation will increase the temperature of environment called global warming.

2  It will increase the carbon dioxide in atmosphere.

3  It will decrease the rainfall.

Q3: how are petroleum and natural gas formed?

Ans: these are formed by dead bodies of plants and animals in the sea. That were died many years ago. By temperature and pressure, these plants and animals change its states. The liquified state is called petroleum and gaseous state is called natural gas.

PART- C

Q1: what is shifting cultivation? What impact does it have on forests ?

Ans: it is a practice of growing crops on a land by clearing the forest of that area.when fertility of that land decreases then moved to the other one was until the fertility of that land regains by naturally. This is called shifting cultivation it is practice in North eastern India.

Impacts of shifting cultivation

1 It causes Large destruction of forests.

2  It causes the loss of biodiversity.

Q2: what different ways does large scale login for timber destroy forest?

Ans: we use timber for making things like houses, chair ,doors  etc . The need of timber continuously increases with the increase in the population. We are destroying forest is for the basic need of human being. For transpotation of things we are destroying forest and making their roots stop this will encourage hunters that will kill the wild animals.

Q3: how does deforestation causes floods and droughts? 

Ans:1 trees break the flow of rainwater when all the trees from mountain cut down the water falls down very fastly. By this common river water will flow. It causes the flood in lower land.

2 trees hold the water and release it slowly. They also increase the water holding capacity of a soil and it maintain the water level in the ground. By, it causes the shortage of water even in heavy rain for reason also it leads to drought in that area.

Q4: write briefly about the four stages in the formation of coal?

Ans: four stages are following

Peat: it is first stage of coal formation peat have 55 - 65% of carbon content. It is present near the Earth's surface.

Lignite: it is second stage of coal formation lignite have 65 - 75% of carbon content it is present below peat upto Depth of 1000 It is Brown coal.

Bituminous: it is third stage of coal formation. It has carbon content 75 - 90%. It is present below it up to Depth of 3000m.

Anthracite: it is the fourth stage of coal formation. It have carbon content above above 90% it present below bituminous it is also known best quality coal.

55-65% of C = peat

65-75% of C =  1000  m      = lignite

75-90% of C=  3000   m          = bituminous

90% above   = 6000   m            = anthracite

CHAPTER- NATURAL RESOURCES

ANMOL (8TH-D){1}