Sunday, 3 July 2016

Chapter 5 Minerals and energy resources

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 Jharkhand 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
(b) metamorphic rocks
(c) igneous 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- conventional sources of energy.
(ii) What is a mineral?
(iii) How are minerals formed in igneous and metamorphic rocks?
(iv) Why do we need to conserve mineral resources?

i)a)Ferrous minerals:-Metallic minerals which contain iron are called ferrous minerals, e.g. iron ore,  manganese, nickel, cobalt, etc.
Non-ferrous minerals:-Metallic minerals which do not contain iron are called non-ferrous minerals, e.g. copper, bauxite tin, etc.

b) Conventional Sources of Energy:-Conventional sources of energy are those sources which have been use since the early times. Non-conventional Sources of Energy:-Non- conventional sources of energy have generally been identified in the recent past.

ii) A mineral is a homogeneous, naturally occurring substance with a definable interior structure.

iii) In igneous and metamorphic rocks, molten/ liquid and gaseous minerals are forced upwards into the cracks. They then solidify and form veins or lodes.

iv) It takes millions of years for the formation of minerals. Compared to the present rate of consumption, the replenishment rate of minerals is very slow. Hence, mineral resources are finite and non- renewable. Due to this, it is important that we conserve the mineral resources.

3) Answer the following questions.
(i) Describe the distribution of coal in India.
(ii) Why do you think that solar energy has a bright future in India?

ANSWER: - i) In India coal occurs in rock series of two main geological ages, namely Gondwana, a little over 200 million years in age and in tertiary deposits which are only about 55 million years old.

The major resources of Gondwana coal, which are metallurgical coal, are located in Damodar valley (West Bengal- Jharkhand) . Jharia, Raniganj, Bokaro are important coalfields. The Godavari, Mahanadi, Son and Wardha valleys also contain coal deposits. Tertiary coals occur in the north eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland. Jharkhand is the largest producer where Jharia, Bokaro , karampur , Palamu are the major coal fields . In West Bengal, Raniganj , Jalpaiguri and Darjeeling are the coal fields . Sarguja, Bilaspur , Raigarh and Bastar districts are coal fields found in Chhatisgarh . MP. has coal fields in Chinaware district and in Maharashtra.

ii) Solar energy has bright future in India because-

a. India is blessed with plenty of solar energy because most part of the country receive bright monsoon period.
b. India has developed technology to use solar energy for cooking, water heating, space heating, crop drying, etc.
c. It is the abundant, inexhaustible and universal source of energy.
d. India is tropical country.