NCERT Solutions for Class 10 Geography Social Science Ch 5 - Minerals and Energy Resources
Exercises, Page - 61
1. Multiple choice questions.
(i) Which one of the following minerals is formed by decomposition of rocks, leaving a residual mass of weathered material ?
(a) coal (b) bauxite (c) gold (d) zinc
Answer: (b) bauxite
(ii) Koderma, in Jharkand is the leading producer of which one of the following minerals ?
(a) bauxite (b) mica (c) iron ore (d) copper
Answer: (b) mica
(iii) Minerals are deposited and accumulated in the stratas of which of the following rocks ?
(a) sedimentary rocks (c) igneous rocks
(b) metamorphic rocks (d) none of the above
Answer: (a) sedimentary rocks
(iv) Which one of the following minerals is contained in the Monazite sand ?
(a) oil (b) uranium (c) thorium (d) coal
Answer: (c) thorium
2. Answer the following questions in about 30 words.
(i) Distinguish between the following in not more than 30 words.
(a) ferrous and non-ferrous minerals.
(b) conventional and non-convetional sources of energy
Answer:
(a) 
(b)
(ii) What is a mineral ?
(b)
Answer:
Mineral is a homogeneous, naturally occuring substance, with a definable internal structure.
(iii) How are minerals formed in igneous and metamorphic rocks ?
Answer:
In Igneous and metamorphic rocks, minerals may occur in the cracks, creices faults or joints. The smaller occurences are called veins and the larger lodes. Minerals like Tin, Copper, Zinc and Lead are obtained from veins and lodes.
(iv) Why do we need to conserve mineral resources ?
Answer:
Minerals are a finite and non-renewable resource. We are using these resources at a fast rate. These will not last long. Mineral formation and rate of replenishment is very slow. We must consume mineral resources for human existence and for the use by future generations.
3. Answer the following questions in about 120 words.
(i) Describe the distribution of coal in India.
Answer:
Coal is the prime source of energy. It is often called the 'Mother of Industries'. It has been the basis of industrial revolution. Coal is used as a raw material in iron and steel, chemical industries. India ranks seventh in the world as regards coal reserves. The total proven coal reserves are nearly 2,14,000 million tonnes. These reserves will not last long. The major states known for coal reserves are Jharkand, Bihar, Orissa, West Bengal, Chhattisgarh, M.P., Andhra Pradesh and Maharashtra.
Coal production started in 1774 in Raniganj coal field (West Bengal). After Independence production of coal has increased ten times.
Production of iron ore in India :
The per capita consumption of coal has increased from 135 kg to nearly 225 kg .
Distribution - India has two types of coal fields in India :
- Gondwana coal fields (98%)
- Tertiary coal field (2%)
1. Gondwana coal fields - These belong to period of Gondwana age (200 million years ago). Nearly 3/4th of coal deposits are found in Damodar valley (Damuda series ). Godavari, Mahanadi, Son and Wardha valley have also coal deposits.
(a) West Bengal - West Bengal has the oldest coal field of India at Raniganj. It covers an area of 1267 sq.km.
(b) Jharkand and Bihar - These two states produce50% coal of India. The major coalfields of Jharia, Bokaro, Karanpura, Daltonganj are found in Damodar valley. Coking coal from this coalfield is supplied to steel centres of Jamshedpur, Asansol, Durgapur and Bokaro.
(c) Chhattisgarh and Madhya Pradesh have son valley coalfields of Suhagpur, Korba, Rampur, Tatapani, Singrauli.
(d) Singareni in Andhra, Talchar in Mahanadi valley, Chanda-Wardha coalfields of Maharashtra.
2. Tertiary coalfields - This includes lignite deposits called brown coal of low quality.
(ii) Why do you think that solar energy has a bright future in India ?
Answer:
It is the most abundant, cheapest and inexaustible source or energy produced from sunlight. Solar cookers are used in cooking food. Solar power is being used for cooking, water heating, water desalination, space heating, crop drying. Solar energy is going to be the energy of the future.
India is a tropical country. It has bright sunshine throughout the year. Photovoltaic technology converts sunlight directly into electricity. The largest solar plant of India is at Madhopur (Bhuj). It is used to sterlise milk cans. Rural households will save fire woods and dung cakes. India has not adequate resources of coal and petroleum. So we must develop Solar power.