Goa Board Class 8 Solutions for Geography – Mineral and Power Resources (English Medium)
Page No. 37:
Question 1:
Answer the following questions.
- Name any three common minerals used by you everyday.
- What is an ore? Where are the ores of metallic minerals generally located?
- Name two regions rich in natural gas resources.
- Which sources of energy would you suggest for
(a) Rural areas
(b) Coastal areas
(c) Arid regions - Give five ways in which you can save energy at home.
Solution :
- The three common minerals used every day are – iron, copper and lead.
- An ore is the rock from which minerals are mined. The ores of metallic minerals are generally located in igneous and metamorphic rock formations that often form large plateaus.
- Russia and the United Kingdom are the two regions rich in terms of natural gas resources.
- (a) Rural areas – Biogas
(b) Coastal areas – Tidal and hydel energy
(c) Arid regions – Solar and wind energy - The five ways in which energy can be saved at home are as follows:
(a) Switching off electrical appliances and equipment when not in use.
(b) Regular overhauling of electrical appliances.
(c) Use of energy efficient technologies and equipment.
(d) Using energy sparingly while performing household tasks. For example, one can put a lid on kitchen utensils while cooking.
(e) Preventing any possibility of leakages in the energy supply to the household.
Question 2:
Solution :
Question 3:
Give reasons.
- Environmental aspects must be carefully looked into before building huge dams.
- Most industries are concentrated around coal mines.
- Petroleum is referred to as ”black gold”.
- Quarrying can become a major environmental concern.
Solution :
- Dams generate hydroelectric power which goes a long way in satisfying the energy needs of a region. However, damns also tend to have many negative effects on the surroundings. The flooding of the surrounding areas tends to destroy the local ecosystem. The natural course of rivers might be changed by the construction and it also leads to widespread displacement of locals. As a result, before the construction of any dams, the environmental repercussions must be taken into detailed consideration.
- Coal is the most abundantly available fossil fuel in the world. It is used as raw material for several important industries. Most of such industries are concentrated around coal mines as the physical proximity helps in cutting down both the time and the cost of transportation.
- Petroleum in its crude form is black in colour and it has come to be seen to be as valuable to humans as the metal gold. Therefore, petroleum is often referred to as ‘black gold’.
- Quarrying involves the clearing of surface vegetation. This badly affects the top soil which contains the ‘humus’ that is necessary for growth of plants. It also involves the use of explosives and earth-moving machinery. This leads to massive noise pollution and can also damage nearby constructions like civilian buildings, dams, etc. The quarrying process also generates a lot of dust and the fossil fuels used in the process greatly pollute the air. Therefore, quarrying as an industrial process can become a major environmental concern.
Question 4:
Distinguish between the following.
- Conventional and non conventional sources of energy
- Biogas and natural gas
- Ferrous and nonferrous minerals
- Metallic and nonmetallic minerals
Solution :
i)
Conventional Sources of Energy |
Non-conventional Sources of Energy |
They have historically been in common use. | They have not been commonly used by laymen. |
They are generally exhaustible. | They are not generally exhaustible. |
They cause large scale pollution. | They are largely non-polluting. |
Examples include coal, firewood, etc. | Examples include solar energy, nuclear energy, etc. |
ii)
Biogas |
Natural Gas |
It is produced by using organic matter like dead plants, animal dung, kitchen waste, etc. | It is found along with petroleum and gets released when crude oil is brought to the surface. |
It is a non-conventional source of energy. | It is a conventional source of energy. |
It is easily available, especially in the rural areas. | It is not easily available. |
It pollutes the environment since it releases carbon-dioxide in the air. | It is a cleaner fuel than many others. |
It is used for domestic purposes like cooking and lighting. | It is used domestically as well as in the industrial sector. |
iii)
Ferrous Mineral |
Non-ferrous Mineral |
It is the metallic mineral that contains iron. | It is the metallic mineral that does not contain iron. |
Examples include manganese, iron ore, etc. | Examples include silver, gold, etc. |
iv)
Ferrous Mineral |
Non-ferrous Mineral |
It contains metal in raw form. | It does not contain metal. |
Examples include iron ore, bauxite, etc. | Examples include gypsum, limestone, etc. |