Q.1. Name the two varieties of iron ore in India having high content of iron. Mention the names of places in India which have the richest iron ore deposits. Explain two effects on our economy due to export of good quality ores in large quantities.
Ans. The two varieties of iron ore of India having high iron content are magnetite and hematite. Magnetite is the finest quality iron ore with very high iron content upto 70 per cent. Hematite has an iron content of 50 to 60 per cent but is the most important industrial iron ore in terms of the quantity used.
Rich iron-ore deposits are found in the following regions of India :
(i) Orissa-Jharkhand belt with high grade hematite iron ore in Badampahar mines in the Mayurbhanj and Keonjhar districts of Orissa, and Gua and Noamundi in the Singhbhum district of Jharkhand.
(ii) Durg-Bastar-Chandrapur belt in Chhattisgarh and Maharashtra with super-high grade hematite iron ore, in the famous Bailadila range of hills in the Bastar district of Chhattisgarh.
(iii) Bellary-Chitradurga-Chikmaglur-Tumkur belt in Karnataka has large reserves of iron ore. The Kudremukh mines located in the Western Ghats are known to be one of the largest deposits in the world.
(iv) Maharashtra-Goa belt includes Ratnagiri and Chandrapur in Maharashtra and Bicholiam and Pali in Goa.
About half of the iron-ore produced in the country is exported primarily to Japan, Korea, European countries and Gulf countries. Paradip, Vishakhapatnam, Mangalore and Marmagao are the main iron exporting ports.
Export of good quality ores in large quantities have positive as well as negative effects. The export of the ore earns huge quantities of foreign exchange which is imperative for development activities.
The export of good quality ores has a negative effect on industrial production within the country which lags in production of iron and steel in spite of having good reserves of iron ore.
Q.2. What are the differences between hydro-electricity and thermal electricity? What is nuclear electricity?
Ans. Hydro-electricity and thermal electricity are two main forms of commercial conventional sources of energy. The main points of difference between these two types of energy sources are as follows :
Nuclear electricity or atomic energy is obtained by altering the structure of atoms of minerals like uranium and thorium. When such atomic alteration is made, much energy is released in the form of heat and this is used to generate electric power.
Q.3. Name the ore from which aluminium is obtained. Why is aluminium considered to be an important metal? Name the areas which have rich deposits of the ore of aluminium.
Ans. Aluminium is obtained mainly from bauxite. Though several ores contain aluminium, it is from bauxite, a reddish-brown, residual clay-like substance, that alumina and later aluminium is obtained. Bauxite deposits are formed by the decomposition of a wide variety of rocks rich in aluminium silicates.
Aluminium is considered to be an important metal because of its properties and wide variety of uses.
(i) It combines the strength of metals such as iron with extreme lightness. So it is used for manufacturing of aircrafts and transport vehicles.
(ii) It has great malleability. It is used for construction purposes to make door, windows, rods and for making utensils.
(iii) It also has quality of good conductivity and is used in electrical conductors.
Rich deposits of bauxite, the ore of aluminium, are found mainly in the Amarkantak plateau, Maikal hills and the plateau region of Bilaspur-Katni in Madhya Pradesh and Chhattisgarh. Orissa is the leading producer accounting for about 45 per cent of the total bauxite production in the country. Panchpatmali deposits in Koraput are an important bauxite reserve in Orissa.
Q.4. State the facts about coal found in India with reference to the following :
(a) their total reserves
(b) its importance as a source of energy and as a source of raw material
(c) its main varieties
(d) distribution of coal in India
Ans. Coal is the most abundantly available and important fossil fuel in India.
(a) Total reserves of coal : India has coal reserve of about 2,14,000 million tonnes. They occur in the rock series of two main geological ages, the Gondwana, a little over 200 million years in age, and in Tertiary deposits which are about 55 million years old.
(b) It is important as a source of energy and as a source of raw material: Coal is the main source of power generation in India. It provides a substantial part of the nation’s energy needs for both industries and domestic purposes. It is the prime source of energy in the manufacturing of iron and steel. Coal is also used as raw material for the chemical industry.
(c) Its main varieties are :
(i) Anthracite — highest quality hard coal with more than 80 percent carbon content.
(ii) Bituminous — most popular coal for commercial use with 60 to 80 percent cabon content.
(iii) Lignite — low grade brown coal with high moisture content and lesser combustible matter with about 60 percent content.
(iv) Peat – produced from decaying plants in swanps with low cabon content of less than 50 percent, high moisture content and low heating capacity.
(d) Distribution of coal in India: The distribution of coal in India is more abundant on the eastern side of the country. In India, coal occurs in rock series of two main geological ages—Gondwana and tertiary. While Gondwana coal is about 200 million years old, tertiary deposits are approximately 55 million years old. The major resources of Gondwana (metallurgical) coal are located in the Damodar valley (West Bengal, Jharkhand), Jharia, Raniganj and Bokaro. The Godavari, Mahandi, Son and Wardha valleys also contain coal deposits. Tertiary coals occur in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.
Q.5. How is petroleum an important source of both energy and raw material? Mention the names of the areas which have rich petroleum deposits.
Ans. Petroleum or mineral oil is a major energy source in India. It provides fuel for heating and lighting. It is used as a fuel for running automobiles, trains, aeroplanes and ships. Petroleum is used for generation of thermal electricity which is a major source of power for commercial purposes.
A number of byproducts are obtained from fractional distillation of petroleum which are used as raw materials for various industries. Chemical fertilisers, insecticides and chemicals and plastics are manufactured from petrochemicals. It also provides raw materials for synthetic textile and synthetic rubber industries.
About 63 percent of India’s petroleum production comes from the drilling areas of Mumbai High and Bassien in the Arabian Sea. Aliabet is another oilfield off-shore the coast of Gujarat. 18 percent of petroleum production comes from Gujarat. Ankaleshwar and Kalol are important oilfields in this region.
16 percent of the production comes from Assam. Assam is the oldest oil-producing state. Oil was first discovered in Makum in Assam in 1867 and the first oilfield was drilled at Digboi. Digboi, Naharkatiya, Moran-Hugrijan, Sibsagar are important oilfields of Assam.
Oil has also been discovered in Kaveri, Krishna and Godavari basins and at Jawalamukhi in Himachal Pradesh.
Q.6. Why do we need to conserve our mineral resources? Explain any three methods of conservation of minerals.
Ans. Minerals are required in all spheres of our life–for agriculture, industries and domestic purposes. We are rapidly consuming the mineral resources that required millions of years to be created and concentrated. The geological processes of mineral formation are so slow that the rates of replenishment are infinitely small in comparison to the present rates of consumption. They are finite resources that are non-renewable, yet are getting exhausted due to rapid exploitation. Continued extraction bring down their quality as well as increases costs of extraction. To save these valuable resources from exhaustion and to preserve them for future generations as well, we should conserve our mineral resources.
Three methods of conserving minerals are :
(i) Causing Minimum wastage of minerals during the process of mining and processing of minerals.
(ii) Improved technologies to utilise low-grade ores at low cost.
(iii) Using minerals in a planned manner by adopting the policy of recycle and reuse. Recycling of metals, using scrap metals and other substitutes to reduce exploitation of present deposits.
Q.7. In recent years, use of which fuel for transport vehicles is gaining popularity? What development has provided impetus to India’s gas production?
(i) In recent years, use of Compressed Natural Gas (CNG) for transport vehicles is gaining popularity. It is replacing liquid fuels like petrol and diesel. The liquid fuels obtained from petroleum are exhausting rapidly and are costlier. They cause enormous pollution. Hence, the use of Compressed Natural Gas is encouraged to control pollution, protect the environment and the conserve petroleum which is exhausting rapidly. In Delhi CNG has already gained wide popularity. CNG is being encouraged with the motto of cleaner city, with government initiative.
(ii) The 1700 km long Hazira-Bijapur-Jagdishpur cross-country gas pipeline links Mumbai High and Bassein with the fertiliser, power and industrial complexes in western and northern India.
This artery has provided impetus to India’s gas production by linking gas-producing areas to their market. As gas can easily be transported via pipelines, the natural gas can be taken from source areas directly to their demand areas.