Find out the source of water in your region/locality. Is water from this source available to all people living in that area?
In our region or locality water sources are only available to those people or the area which are approved by the local-civic authority. The water is supplied by the government agencies at the particular timing through the taps only when we on the motors. The government agencies supplied the water from the lakes, ponds etc. to their homes directly. In the rural areas, people obtain water from the ponds, wells, streams and rivers. These water sources are used by the people for all uses like cooking food, drinking, washing clothes etc; and in urban areas, water collection occurs. In this water transport occurs through the canals, tunnels, pipelines from these sites to the water harvesting systems.
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.
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?
Why do you think that there should be equitable distribution of resources? What forces would be working against an equitable distribution of our 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?
Why does the sky appear dark instead of blue to an astronaut?
What are the advantages of sexual reproduction over asexual reproduction?
How is the amount of urine produced regulated?
The kidneys in human beings are a part of the system for
(a) nutrition. (c) excretion.
(b) respiration. (d) transportation.
How does chemical coordination occur in plants?
What processes would you consider essential for maintaining life?
A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10–8 Ω m. What will be the length of this wire to make its resistance 10 Ω? How much does the resistance change if the diameter is doubled?
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be
(a) only plane.
(b) only concave.
(c) only convex.
(d) either plane or convex.
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