Question 1

Q1: (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) g...

Accepted Answer

Answer: (b) bauxite Explanation: The source material states that one mode of mineral formation involves the decomposition of surface rocks and the removal of soluble constituents, which leaves a residual mass of weathered material containing ores. It explicitly mentions, "Bauxite is formed this way....

Question 2

Q2: (ii) Koderma, in Jharkhand is the leading producer of which one of the following minerals? (a) bauxite (b) mica (c) iron ore (d) copper

Accepted Answer

Answer: (b) mica Explanation: The text specifies that mica deposits are found on the northern edge of the Chota Nagpur plateau and identifies the "Koderma Gaya - Hazaribagh belt of Jharkhand" as the leading producer of mica.

Question 3

Q3: (iii) Minerals are deposited and accumulated in the stratas of which of the following rocks? (a) sedimentary rocks (b) metamorphic rocks (c) igneous r...

Accepted Answer

Answer: (a) sedimentary rocks Explanation: According to the chapter, in sedimentary rocks, a number of minerals occur in beds or layers. These minerals have been formed as a result of deposition, accumulation, and concentration in horizontal strata.

Question 4

Q4: (iv) Which one of the following minerals is contained in the Monazite sand? (a) oil (b) uranium (c) thorium (d) coal

Accepted Answer

Answer: (c) thorium Explanation: In the section on Nuclear or Atomic Energy, the text mentions that Uranium and Thorium are used for generating atomic power. It further states, "The Monazite sands of Kerala is also rich in Thorium."

Question 5

Q1: (i) Distinguish between the following in not more than 30 words. (a) ferrous and non-ferrous minerals (b) conventional and non-conventional sources of...

Accepted Answer

(a) Ferrous and non-ferrous minerals: Ferrous minerals contain iron, form the base for metallurgical industries, and account for about three-fourths of the total value of metallic mineral production. Examples are iron ore and manganese. Non-ferrous minerals do not contain iron, and include copper, b...

Question 6

Q2: (ii) What is a mineral?

Accepted Answer

According to geologists, a mineral is a "homogenous, naturally occurring substance with a definable internal structure." Minerals are found in varied forms in nature, from the hardest diamond to the softest talc, and are the constituent substances of rocks.

Question 7

Q3: (iii) How are minerals formed in igneous and metamorphic rocks?

Accepted Answer

In igneous and metamorphic rocks, minerals are formed when they are in liquid, molten, or gaseous forms and are forced upward through cavities like cracks, crevices, faults, or joints. As they rise towards the earth's surface, they cool and solidify, forming veins (smaller occurrences) or lodes (lar...

Question 8

Q4: (iv) Why do we need to conserve mineral resources ?

Accepted Answer

We need to conserve mineral resources because they are finite and non-renewable. The geological processes of mineral formation are extremely slow. Continued extraction of these resources at a fast rate will lead to their depletion, and future generations will be deprived of them. Conservation ensure...

Question 9

Q1: (i) Describe the distribution of coal in India.

Accepted Answer

In India, coal occurs in rock series of two main geological ages: Gondwana and Tertiary.    Gondwana Coal: These deposits are over 200 million years old and contain metallurgical coal. The major resources are located in the Damodar valley in West Bengal and Jharkhand, with Jharia, Raniganj, and Boka...

Question 10

Q2: (ii) Why do you think that solar energy has a bright future in India?

Accepted Answer

Solar energy has a bright future in India for several compelling reasons based on the country's geographical advantages and economic needs.    Abundant Sunlight: India is a tropical country and is blessed with an abundance of sunlight throughout the year. This provides enormous potential for tapping...

Question 11

Q1: Fill the name of the correct mineral in the crossword below: Across 1. A ferrous mineral (9) 2. Raw material for cement industry (9) 3. Finest iron or...

Accepted Answer

Across 1. MANGANESE 2. LIMESTONE 3. MAGNETITE 4. ANTHRACITE 5. BAUXITE 6. COPPER 7. GYPSUM Down 1. GOLD 2. HEMATITE 3. MICA 4. TERTIARY 5. TIN

NCERT Solutions