The study of geography involves knowledge of places, understanding of the maps and environment throughout the world. It again involves a link between nature and the social sciences which are the human behavior. Students can encounter the size of population, physical features of India, natural vegetation and wildlife and everything one should be familiar with climate. You will learn to value the planet in which we live in and its people. CoolGyan makes these concepts easy to understand and fun to study.
Geography Revision Notes for Class 10

Ans: (i) (a) 

Ferrous minerals	Non-ferrous minerals
Metallic minerals which contain iron are called ferrous minerals, e.g.. iron ore, manganese, nickel, cobalt, etc. They have small amounts of other metals or elements added, to give the required properties. Ferrous Metals are magnetic and give little resistance to corrosion.	Metallic minerals which do not contain iron and are not magnetic and are usually more resistant to corrosion than ferrous metals are called non-ferrous minerals, e.g.. copper, bauxite, tin, etc.

(b)

Conventional Sources of Energy	Non-conventional Sources of Energy
Conventional sources of energy are those sources which have been in use since the early times.	Non-conventional sources of energy have generally been identified in the recent past.
They are exhaustible except hydro-energy.	They are inexhaustible.
They cause pollution when used as they emit smoke and ash.	Generally, these are pollution-free.
Their generation and use involve huge expenditure.	Low expenditure required.
Very expensive to maintain, store, transmit as they are carried over long distances through transmission grids.	Less expensive due to local use and easy maintenance.
Examples are – coal, natural gas, water, fire-wood.	Examples are – geothermal energy, solar energy, wind energy, tidal energy, biogas energy, nuclear energy.

(ii) A mineral is a homogeneous, naturally occurring substance with a definable interior structure. They are found in varied forms in nature, ranging from the hardest diamond to the softest talc. A mineral is a naturally occurring chemical compound, usually of crystalline form and not produced by life processes. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals
(iii) In igneous and metamorphic rocks minerals may occur in the cracks, crevices, faults or joints. They are formed when minerals in liquid/ molten and gaseous forms are forced upward through cavities towards the earth’s surface. They then solidify as they rise towards the surface. and form veins or lodes. Minerals like tin, copper, zinc and lead etc. are obtained from veins and 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. Rich mineral deposits are our country’s extremely valuable but short lived possessions. Continued extraction of ores leads to increasing costs as mineral extraction comes from greater depths along with a decrease in quality. A concerted effort has to be made in order to use our mineral resources in a planned and sustainable manner.

---

Ans: (i) India has the fifth largest coal reserves in the world, and is the fourth largest producer of coal in the world: 

• The major resources of metallurgical coal belong to the Gondwana age and are located mainly in the northeastern part of the peninsula.
• Rich reserves of coal are found in the Damodar Valley region in the states of West Bengal and Jharkhand. Raniganj in WestBengal and Jharia and Bokaro in Jharkhand are important coalfields. One third of the total production comes from here.
• Coal is also found in the Godavari, Mahanadi, Son and Wardha valleys. Korba in Chhattisgarh, Singrauli and Penah-kanhan valley in Madhya Pradesh, Talcher in Orissa, Kamptee and Chandrapur in Maharashtra and Singareni of Andhra Pradesh are important coal mines.
• Tertiary coal occurs in the northeastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.
• Principal lignite reserves are found in Neyveli in Tamil Nadu. Due to high demand and poor average quality, India is forced to import high quality coal to meet the requirements of steel plants.
• Dhanbad city is the largest coal producing city.

(ii) Solar energy has a bright future in India because –

• India being a tropical country receives sunlight in abundance throughout the year.
• Solar plants can be easily established in rural and remote areas.
• Photovoltaic technology converts sunlight directly into electricity.
• It will minimize the dependence of rural households on firewood and dunk cakes which in turn will contribute to environmental conservation and adequate supply of manure in agriculture.