NCERT Exemplar Solutions for Class 10 Science Chapter 16 Management of Natural Resources

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NCERT Exemplar Solutions for Class 10 Science Chapter 16 Management of Natural Resources

These Solutions are part of NCERT Exemplar Solutions for Class 10 Science. Here we have given NCERT Exemplar Solutions for Class 10 Science Chapter 16 Management of Natural Resources

NCERT Exemplar Solutions for Class 10 Science Chapter 16 Short Answer Questions

Question 1.
Prepare a list of items that you use daily in the school. Identify from the list five such items that can be recycled.
Answer:
Items. Rexin bag, steel lunch box, steel spoon, steel compass, steel dividers, paper, plastic box, pen, pencil, blade, eraser, handkerchief.
Recycleable Items. Steel lunch box, steel spoon, steel compass, steel dividers, blade, paper, plastic box.

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Question 2.
List the advantages associated with water harvesting at the community level. (CCE 2012)
Answer:
Water harvesting at the community level is capturing, collection and storage of rain water and surface run off for filling either small water bodies or recharging ground water. This is carried out through water shed management, check dams, earthen dams, roof top harvesting and filter wells in flood drains.
Benefits:

  1. It ensures water availability in non-rainy season,
  2. It reduces the chances of flooding during rainy season,
  3. Ground water level does not fall as it is regularly recharged,
  4. Ground water recharge is the best form of water harvesting as the water is filtered and free from contaminations. It also does not evaporate,
  5. Water becomes available for drinking as well as irrigation.

Question 3.
In a village in Karnataka people started cultivating crops all around a lake which was always filled with water. They added fertilizers to their field in order to enhance the yield. Soon they discovered that the water body was completely covered with green floating plants and fishes started dying in large numbers.
Analyse the situation and give reasons for excessive growth of plants and death of the fish in the lake.
Answer:
Fertilizer rich run off from fields must have passed into the lake. It caused nutrient enrichment of lake water. The result is excessive growth of algae and other aquatic plants which float on the water surface and produce water bloom. Old dead plants produce a lot of organic matter. The submerged plants are also killed due to shading. BOD of water increases. As more and more oxygen is consumed by decomposers little is left for respiration of aquatic animals. Therefore, fish begin to die. The phenomenon of nutrient enrichment of water body that causes formation of water bloom and subsequent killing of aquatic life is called eutrophication.

Question 4.
What measures would you take to conserve electricity in your house ? (CCE 2012)
Answer:

  1. Judicious use of electricity by switching off lights and electrical appliances not required,
  2. Replacement of incandescent bulbs with fluorescent, compact fluorescent ones and LED bulbs.
  3. Replacement of electricity or gas operated geysers with solar water heaters,
  4. Replacement of electricity generating sets with solar light,
  5. Having more natural light and ventilation with design supporting warming during winters and cooling during summer.

Question 5.
Although coal and petroleum are produced by degradation of biomass, yet we need to conserve them. Why ? (CCE 2012)
Answer:
Coal and petroleum have been produced from large amounts of biomass entrapped inside the earth under high temperature, pressure and anaerobic conditions. Such a situation develops only rarely like big upheavals on earth. At present no more coal or petroleum is being formed. All that is available has been formed millions of years ago. Being rich source of energy, coal and petroleum are being consumed in ever increasing amount in industry, transport, kitchens, etc. If the trend continues, soon they will be exhausted. Therefore, they must be conserved by developing more efficient machines, hybrid engines and using hydrogen as a fuel.

Question 6.
Suggest a few measures for controlling carbon dioxide levels in the atmosphere.
Answer:

  1. Increasing Vegetation Cover. It will increase utilisation of atmospheric CO2 in photosynthesis.
  2. Seeding of Oceans With Phytoplankton. Increased photosynthetic activity of oceans will result in decreasing CO2 concentration.
  3. Carbonation. CO2 released during combustion should not be allowed to pass into atmosphere. Instead, it can be changed into carbonates.
  4. Alternate Sources of Energy. Instead of fossil fuels, hydrogen fuel and solar energy should be used.
  5. Burning of Litter. Litter and crop residue should not be burnt but instead converted into manure.

Question 7.
(a) Locate and name the water reservoirs in figures (i) and (ii).
(b) Which has advantage over the other and why ?
NCERT Exemplar Solutions for Class 10 Science Chapter 16 Management of Natural Resources image - 1
Answer:
(a) Water reservoir in figure (i) is pond while it is underground water body (ground water) in figure (ii).
(b) Ground water is more advantageous than pond water.
For Benefits: 

  1. Prevents flooding,
  2. Checks soil erosion.
  3. Retains water underground and prevents drought,
  4. Increases life of downstream reservoirs and dams,
  5. Higher biomass production and income of water shed community,
  6. Maintenance of ecological balance.

NCERT Exemplar Solutions for Class 10 Science Chapter 16 Long Answer Questions

Question 8.
In the context of conservation of natural resources, explain the terms reduce, recycle and reuse. From among the materials that we use in daily life, identify two materials for each category.
Answer:
Three Rs — reduce, recycle and reuse.

  1. Reduce: It is to reduce consumption by preventing wastage.
    1. Switching off unnecessary lights, fans and other electrical appliances,
    2. Repair of leaky taps.
    3. Reducing food wastage,
    4. Walking down to nearby market instead of using vehicle.
  2. Recycle: Separation of recyclable wastes from non-recyclable wastes. The former are taken by rag pickers for sending them to industries involved in recycling, e.g., paper, plastic, metal, glass.
  3. Reuse: Carry bags, packing material, plastic containers and other reusable articles should not be thrown away if the same are uncontaminated. For example, plastic bottles and jars containing various food items brought from market can be washed and used for storing things in the kitchen.

Question 9.
Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimised.
Answer:

  1. Judicious use of electricity by switching off lights and electrical appliances not required,
  2. Replacement of incandescent bulbs with fluorescent, compact fluorescent ones and LED bulbs.
  3. Replacement of electricity or gas operated geysers with solar water heaters,
  4. Replacement of electricity generating sets with solar light,
  5. Having more natural light and ventilation with design supporting warming during winters and cooling during summer,
  6. Reducing wastage of water, food and other articles.
  7. Separation of recyclable waste from non-cyclable waste prior to disposal.
  8. Increasing reuse of containers,
  9. Using cloth bags instead of polythene, plastic or paper bags.

Question 10.
Is water conservation necessary ? Give reasons.
Answer:

  1. Distribution of fresh water is highly uneven. Large tracts are deficient in rain as well as ground water,
  2. At most places more water is withdrawn from reservoir and underground source than their recharging
  3. Requirement in urban and industrial areas is nearly always higher than the availability,
  4. Further demand for water is rising by 4 – 8% annually in all fields, whether agriculture, industry or domestic use.

Therefore, water conservation is necessary. Wastage of the resource should be prevented. Waste water should be recycled. Water harvesting involving recharging of ground water should be practised.

Question 11.
Suggest a few useful ways of utilising waste water.
Answer:
Waste or used water can also become a resource.

  1. Treated municipal water can be poured in irrigation channels for supply to crop fields,
  2. Treated waste water can be used in urban areas for watering gardens, lawns and washing vehicles,
  3. Industries can treat their waste water and recycle the same,
  4. Waste water passed into ponds recharges the ground water,
  5. Sewage sludge, separated from waste water is a source of manure, compost and biogas.

Question 12.
What is the importance of forests as a resource ?
Answer:
Economic Reasons:

  1. Food: Tribals obtain most of their food requirements from the forests, e.g., fruits, tubers, fleshy roots, leaves.
  2. Nuts: Pine Nut (Chilgoza), Almond, Walnut and Cashewnut are obtained from forests trees.
  3. Spices: Cardamom, Cinnamon, Nutmeg and Cloves are spices obtained from forest plants.
  4. Commercial Products: A number of forest products are of commercial importance, g., rubber, resin, tannins, tendu, lac, cork, camphor, essential oils, soap pod and drugs.
  5. Fuel Wood: Nearly two billion persons depend upon forests for fuel wood.
  6. Timber: Wood for the manufacture of furniture, household fitments and several other articles mostly comes from forests. Bamboo is called poorman’s timber as it is used in thatching huts, preparing baskets and a number of other articles including furniture.
  7. Paper: It is prepared from cellulose rich plants like bamboos, Boswellia, Eucalyptus, grasses and several

Protective Functions:                                                                                  i

  1. Forests provide shelter to wild animals. Over 40 million tribals and villagers live in forests.
  2. Plant roots hold the soil firmly. Vegetation protects the soil from action of wind and water. Forests, therefore, protect the soil from erosion and landslides.
  3. Pollution. Forests reduce atmospheric pollution by absorbing gases, collecting suspended particles and reducing noise.

Regulative Functions:

  1. Absorption and Retention of Water. Forests reduce run off, hold water like a sponge and allow slow percolation to form perennial springs and rivulets.
  2. Forests increase atmospheric humidity, increase frequency of rainfall and moderate temperature.
  3. Atmospheric Gases. Forests absorb large quantity^ of C02 from the atmosphere, reducing the threat of global warming. They also release a lot of oxygen.

Question 13.
Why are Arabari forests of Bengal known to be good example of conserved forests.
Answer:
Regeneration of Sal Forests — An Example of People’s Participation in the Management of Forests Despite best efforts, the West Bengal Forest Department could not revive the degraded Sal forests of Southwestern districts of the state. Excessive surveillance and policing of the degraded forests not only alienated the people but also resulted in frequent clashes between villagers and forest officials. This also fueled the militant peasant movement led by Naxalites. Realising the failure, the forest department revised its strategy in 1972. It allowed forest officer A.K. Banerjee of Arabari forest range of Midnapore to involve villagers in regeneration of 1272 hectares of badly degraded Sal forest. Banerjee provided employment to villagers in silviculture (cultivation of trees) and harvesting, 25% of final harvest and allowed collection of fuel wood as well as fodder at nominal fee. By 1983, the Arabari forest had been revived and was then valued at 12-5 crores.

Hope given NCERT Exemplar Solutions for Class 10 Science Chapter 16 Management of Natural Resources are helpful to complete your science homework.

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