On the basis of the issues raised in this chapter, what changes would you incorporate in your lifestyle in a move towards a sustainable use of our resources?
Everyone should incorporate the changes in our life- style moves towards the sustainable use of our resources:-
1. We should promote afforestation (planting the trees) programs instead of deforestation (cutting down the trees).
2. We should carry paper bags and jute bags while leaving the house for the shopping or for taking vegetables etc. instead of taking polythene from the shopkeeper.
3. We should prefer walking or bicycle to cover short distances instead of going on scooty or automobile appliances for controlling the air pollution and the noise pollution as well. And, to cover the long distances we should take buses and vans or we can say public transport instead of taking personal vehicles.
4. We should switch off lights, fans, television which was unnecessarily on to save electricity or energy.
5. We should use pencils for the rough work so that paper can be used again and again.
6. We should stop the tap while brushing the teeth or stop taking shower, use bucket to save water for bathing.
7. Use water harvesting techniques like rain water harvesting system which will be very helpful for surviving in the extreme condition.
8. Use solar panels, hydro- power to save electricity.
9. During winters, wear extra sweaters or clothes to avoid the use of heaters or we can also take hot bags.
10. We should use stairs instead of taking lifts for maintaining our health and for saving the electricity as well.
Find out about the traditional systems of water harvesting/management in your region.
Suggest some approaches towards the conservation of forests.
We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?
List five things you have done over the last one week to —
(a) conserve our natural resources.
(b) increase the pressure on our natural resources.
Find out the source of water in your region/locality. Is water from this source available to all people living in that area?
How can you as an individual contribute or make a difference to the management of (a) forests and wildlife, (b) water resources and (c) coal and petroleum?
Why should we conserve forests and wildlife?
Compare the above system with the probable systems in hilly/mountainous areas or plains or plateau regions.
What changes can you make in your habits to become more environment-friendly?
What can you as an individual do to reduce your consumption of the various natural resources?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
Do basic solutions also have H+(aq) ions? If yes, then why are these basic?
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
How are involuntary actions and reflex actions different from each other?
Why is sodium kept immersed in kerosene oil?
Explain the meanings of malleable and ductile.
What are the advantages of nuclear energy?
Choose the correct option.
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each
(a) two revolutions (b) one revolution
(c) half revolution (d) one-fourth revolution
Find out, from Table 10.3, the medium having highest optical density. Also find the medium with lowest optical density.
Material medium |
Refractive index |
Material medium |
Refractive index |
Air | 1.0003 | Canada Balsam |
1.53 |
Ice | 1.31 | ||
Water | 1.33 | Rock salt | 1.54 |
Alcohol | 1.36 | ||
Kerosene | 1.44 | Carbon disulphide |
1.63 |
Fused quartz |
1.46 | ||
Turpentine oil |
1.47 | Ruby | 1.71 |
Benzene | 1.50 | Sapphire | 1.77 |
Crown glass |
1.52 | Diamond | 2.42 |
Table 10.3 Absolute refractive index of some material media
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
(a) Between the principal focus and the centre of curvature
(b) At the centre of curvature
(c) Beyond the centre of curvature
(d) Between the pole of the mirror and its principal focus.
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
Metal | Zinc | Magnesium | Copper |
---|---|---|---|
Zinc oxide | |||
Magnesium oxide | |||
Cooper oxide |
In which cases will you find displacement reactions taking place?