NCERT Class X Science Class: Chapter –16. Management of Natural Resources – Part-7

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Question 28:

What measures would you take to conserve electricity in your house?

Answer:

Put off the fans and lights when they are not required.

Image off fans and lights

Image off Fans and Lights

Image off fans and lights

(b) Maximum use of solar radiation.

Image Maximum use of solar radiation

Image Maximum Use of Solar Radiation

Image Maximum use of solar radiation

(c) Use of solar water heating system. During winters.

Image Use of solar water heating system

Image Use of Solar Water Heating System

Image Use of solar water heating system

(d) Use of fluorescent tubes or CFL

Image Use of fluorescent tubes or CFL

Image Use of Fluorescent Tubes or CFL

Image Use of fluorescent tubes or CFL

Question 29:

Although coal and petroleum are produced by degradation of bio- mass, yet we need to conserve them. Why?

Answer:

Yes it is true that coal and petroleum are produced by the degradation of biomass but we need to conserve them because it takes millions of years for this biomass to get converted into coal and petroleum. If we use these resources unnecessarily and wasting them then our next generations will not be able to use these resources as at that moment of time these resources might be getting formed and thus will not be available to our next generations.

Question 30:

Suggest a few measures for controlling carbon dioxide levels in the atmosphere.

Answer:

(a) Reduce the consumption of petrol in the automobiles.

(b) Use of CNG or clean fuel

(c) Instead of burning litter prepare manure out of it.

(d) Treatment of smoke to remove harmful gases before discharging into atmospheric

(e) Plant more trees

Question 31:

(a) Locate and name the water reservoirs in Figures (a) and (b).

(b) Which has an advantage over the other and why?

Image Water reservoirs - 1

Image Water Reservoirs - 1

Image Water reservoirs - 1

Image Water reservoirs - 2

Image Water Reservoirs - 2

Image Water reservoirs - 2

Answer:

(A) The water reservoir is a pond in Figure (a) andunderground water body in the Figure (b).

(B) Figure (b) has more advantage than Figure (a),because the advantages of water stored in the ground aremany. For example

(a) It does not evaporate

(b) It spreads out to recharge wells.

(c) Provides moisture for vegetation over a wide area.

(d) It is protected from contamination by animal and human wastes.

(e) It prevents breeding of insects.

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