MINERALS AND ENERGY RESOURCES - Q&A
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
Explanation: Bauxite is formed by the decomposition of surface rocks and the removal of soluble constituents, leaving a residual mass of weathered material containing ores.
(a) bauxite
(b) mica
(c) iron ore
(d) copper
Answer: (b) mica
Explanation: The Koderma-Gaya-Hazaribagh belt of Jharkhand is the leading producer of mica in India.
(a) sedimentary rocks
(b) metamorphic rocks
(c) igneous rocks
(d) none of the above
Answer: (a) sedimentary rocks
Explanation: In sedimentary rocks, a number of minerals occur in beds or layers. They are formed as a result of deposition, accumulation, and concentration in horizontal strata.
(a) oil
(b) uranium
(c) thorium
(d) coal
Answer: (c) thorium
Explanation: The Monazite sands of Kerala are rich in 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
Answer:
Ferrous minerals contain iron (e.g., iron ore, manganese) and account for about three-fourths of the total value of metallic minerals produced. They provide a strong base for metallurgical industries.
Non-ferrous minerals do not contain iron (e.g., copper, bauxite, lead). They play a vital role in metallurgical, engineering, and electrical industries.
Answer:
Conventional sources have been in use for a long time (e.g., firewood, coal, petroleum). They are generally non-renewable and cause pollution.
Non-conventional sources are recently developed (e.g., solar, wind, tidal). They are renewable, eco-friendly, and sustainable for the future.
Answer:
Geologists define a mineral as a "homogenous, naturally occurring substance with a definable internal structure." Minerals are found in varied forms in nature, ranging from the hardest diamond to the softest talc.
Answer:
In igneous and metamorphic rocks, minerals occur in cracks, crevices, faults, or joints. They are usually formed when minerals in liquid/molten and gaseous forms are forced upward through cavities towards the earth's surface. They cool and solidify as they rise (e.g., tin, copper, zinc).
Answer:
Mineral resources are finite and non-renewable. The geological processes of mineral formation are extremely slow compared to the rapid rate of human consumption. Therefore, we must conserve them to ensure they last for future generations.
3. Answer the following questions in about 120 words.
(i) Describe the distribution of coal in India.
Answer:
In India, coal occurs in rock series of two main geological ages:
1. Gondwana Coal (over 200 million years old): This is metallurgical coal. The major resources are located in the Damodar Valley (West Bengal-Jharkhand). Important coalfields include Jharia, Raniganj, and Bokaro. Coal deposits are also found in the Godavari, Mahanadi, Son, and Wardha valleys.
2. Tertiary Coal (about 55 million years old): These deposits occur in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh, and Nagaland.
Coal is a bulky material that loses weight on use as it reduces to ash, which is why heavy industries and thermal power stations are often located near these coalfields.
Answer:
Solar energy has a bright future in India because:
1. Tropical Location: India is a tropical country with an abundance of sunlight, offering enormous possibilities for tapping solar energy.
2. Rural Application: It is fast becoming popular in rural and remote areas. Photovoltaic technology converts sunlight directly into electricity, reducing dependence on firewood and dung cakes.
3. Environmental Benefits: Utilizing solar energy contributes to environmental conservation and ensures an adequate supply of manure for agriculture by saving cow dung from being burnt as fuel.
4. Sustainability: As a non-conventional and renewable source, it addresses the issues of energy shortage and rising prices of fossil fuels.
ACTIVITY
Fill the name of the correct mineral in the crossword below:
ACROSS
1. A ferrous mineral (9)
Answer: MANGANESE
2. Raw material for cement industry (9)Answer: LIMESTONE
3. Finest iron ore with magnetic properties (9)Answer: MAGNETITE
4. Highest quality hard coal (10)Answer: ANTHRACITE
5. Aluminium is obtained from this ore (7)Answer: BAUXITE
6. Khetri mines are famous for this mineral (6)Answer: COPPER
7. Formed due to evaporation (6)Answer: GYPSUM
DOWN
1. Found in placer deposit (4)
Answer: GOLD
2. Iron ore mined in Bailadila (8)Answer: HEMATITE
3. Indispensable for electrical industry (4)Answer: MICA
4. Geological Age of coal found in north east India (8)Answer: TERTIARY
5. Formed in veins and lodes (3)Answer: TIN