RBSE Class 11 Geography Important Questions Chapter 5 Minerals and Rocks

Rajasthan Board RBSE Class 11 Geography Important Questions Chapter 5 Minerals and Rocks Important Questions and Answers. 

RBSE Class 11 Geography Important Questions Chapter 5 Minerals and Rocks

Multiple Choice Questions

1. What are the substances that make up the soil strip?
(A) Rocks
(B) Minerals
(C) Metals
(D) Lava.
Answers:
(A) Rocks

2. What is the extremely hot and molten matrial found under the soil strip?
(A) Lava
(B) Magma
(C) Rayolite
(D) Gabro.
Answers:
(B) Magma

3. The composition of igneous rocks is-
(A) More than pressure
(B) By becoming soild of magma of Lava
(C) By the joining of cracked ravs
(D) From the deposit of the rivers.
Answers:
(B) By becoming soild of magma of Lava

4. Which of the following is a metamorphic rock?
(A) Granite
(B) Graphite
(C) Ghabro
(D) Grit.
Answers:
(B) Graphite

5. Unorganized and broken ravines of the pre-made sheets are made
(A) Seimentary rocks
(B) Bio rocks
(C) Igneous rocks
(D) Metamorphic rocks.
Answers:
(A) Seimentary rocks

6. Which out of the following is an Igneous rock?
(A) Coal
(B) Quarty
(C) Basalt
(D) Lime stone.
Answers:
(C) Basalt

7. Which type of rock is limestone?
(A) Igneous
(B) Sedimentary
(C) Metamorphic
(D) None.
Answers:
(C) Metamorphic

8. Which is the characteristic of Igneous rock?
(A) Layers
(B) Particles
(C) Sediments
(D) Cystals.
Answers:
(D) Cystals.

9. Which out of the following is a metamorphic rock?
(A) Limestone
(B) Basalt
(C) Peat
(D) Sandstone.
Answers:
(A) Limestone

10. Which is the original rock of marble?
(A) Basalt
(B) Granite
(C) Limestone
(D) Ghale.
Answers:
(A) Basalt

Very Short Answer Type Questions

Question 1. 
What is a rock?
Answer: 
Solid materials of lithosphere.

Question 2. 
Name the three main types of rocks.
Answer: 

1. Igneous rocks
2. Sedimentary rocks 
3. Metamorphic rocks.

Question 3. 
What does the word Igneous stand for?
Answer: 
Derived from the Latin word ‘Igins’, it means fire.

Question 4. 
State one example of extrusive Igneous rocks.
Answer: 
Basalt.

Question 5.
On the basis of location, name two types of Igneous rocks.
Answer: 
Extrusive and Intrusive rocks.

Question 6.
Name the three types of Igneous rocks on the basis of origin.
Answer: 
Volcanic rocks, Hypabyssal rocks and Plutonic rocks.

Question 7. 
From which word, the term Plutonic is derived?
Answer: 
From Pluto (the God of underworld)

Question 8. 
State one example of Plutonic rocks.
Answer: 
Granite.

Question 9. 
What does the term ‘Batholith’ mean?
Answer: 
Batholith is a dome-shaped granitic mass of intrusive Igneous rocks.

Question 10. 
What are laccoliths?
Answer: 
Laccoliths are mounds of magma forced from below.

Question 11. 
Name an extensive area in Western India covered with Basalt.
Answer: 
Deccan trap.

Question 12. 
Name three types of sedimentary rocks according to mode of formation.
Answer: 

1. Mechanically formed 
2. Chemically formed 
3. Organically formed.

Question 13. 
What is Grit?
Answer: 
Coarser sandstone is known as Grit.

Question 14. 
What is Conglomerate?
Answer: 
When large rounded pebbles are cemented together conglomerate is formed.

Question 15. 
Name one example of Carbonaceous rocks.
Answer: 
Coal.

Question 16. 
Name the different types of coal.
Answer:
Peat, Lignite, Bituminous and Anthracite.

Question 17. 
Name two fossil fuels found in sedimentary rocks.
Answer: 
Coal and petroleum.

Question 18. 
Name two examples of chemically formed rocks.
Answer: 
Gypsum and Rock salt.

Question 19. 
To which rock are granite and basalt changed?
Answer: 
Granite to gneiss. Basalt to schist.

Question 20. 
To which rocks are shale and coal changed?
Answer: 
Shale to slate; coal to graphite.

Question 21. 
What does ‘lithosphere’ mean?
Answer: 
A sphere of rocks.

Question 22. 
Who is a Petrologist?
Answer: 
A scientist who studies rocks.

Question 23. 
Name the largest diamond found.
Answer: 
Culinan Diamond found in South Africa in 1905 (600 gms).

Question 24. 
From which word of Latin word sedimentary derived?
Answer: 
Sedimentum.

Question 25. 
Metamerphic rocks are divided into two major groups. Name these groups?
Answer: 
Foliated rocks and non-foliated groups.

Short Answer Type Questions

Question 1. 
Why is the knowledge of rocks necessary? 
Answer: 
As there is a close relation between rocks and land-forms and between rocks and soils, it is necessary for a geographer to have basic knowledge of rocks.
 
Question 2. 
What do you mean by Petrology?
Answer: 
Petrology is the science of rocks. A petrologist studies rocks in all their aspects viz. mineral composition, texture, structure, origin occurrence, alteration and relationship with other rocks.

Question 3. 
What do you mean by lithifiction?
Answer: 
Rocks are broken into various sizes of fragments. These are deposited. These deposits through compaction or cementation turn into rocks.

Question 4. 
What is meant by PVT?
Answer: 
It is a brief form of metamorphism.
P = pressure 
V = volume 
T = temperature.
These three are included in this process.

Question 5. 
What is meant by metamorphism?
Answer: 
Metamorphism means change of form. It is a process by which already consolidated rocks undergo recrystallisation and reorganisation of materials within original rocks.

Question 6. 
What is meant by Rock Cycle?
Answer: 
Rock cycle is a continuous process through which old rocks are transformed into new ones.

Question 7. 
Define Rocks. Name the main types of rocks.
Answer: 
Any natural, solid inorganic or organic material out of which the crust is formed is called a rock. It may be hard as granite or soft as clay. Clay, chalk, coal, gravel, etc. are examples of rocks. Lithosphere is made up of rocks. On the basis of their mode of formation, rocks are divided into three types :

1. Igneous rocks.
2. Sedimentary rocks.
3. Metamorphic rocks.

Question 8. 
How are Sedimentary rocks formed?
Answer: 
Sedimentary rocks have been formed by the deposition of sediments brought by wind, ice and river. The sediments are deposited in depressions, lakes and sea. Loose sediments are deposited on horizontal layers. These layers are parallel to one another. These sediments are bonded together by the pressure of upper layers and some cementing material such as silica, calcite, etc.

Question 9. 
Why are the Igneous rocks called Primary; Rocks? i
Answer: 
It is believed that the earth was in a molten state in the beginning. Igneous rocks were the first rocks to be formed due to cooling and solidification of molten matter. Hence, these are called Primary Rocks. 

Question 10. 
Why are fossils preserved in Sedimentary and not in Igneous rocks?
Answer: 
Fossils are remains of vegetation and animals buried under the sediments. The sedimentary rocks are stratified rocks and are found in layers. These fossils are preserved in between these layers. But in Igneous rocks, the fossils are destroyed due to high temperature of lava.

Question 11. 
How are Igneous rocks formed?
Answer: 
Igneous rocks are formed by the solidification of Lava. Lava cools rapidly and solidifies on the surface of earth. Crystals are formed due to the cooling of Lava. These rocks are intrusive as well as extrusive.

Question 12. 
What do you mean by ‘Deccan trap’?
Answer: 
Deccan trap is an extensive area in N. W. part of India covering about 5 lakh sQuestion km. It has been formed by lava flows. Lava has solidified to form Basalt. It is useful for cotton cultivation.

Question 13. 
Describe the economic importance of minerals.
Answer: 
Economic Importance of Minerals.
Mineral resources can be divided into four main groups:

1. essential resources,
2. energy resources,
3. metal resources, and
4. industrial resources.

The most basic group, essential resources, comprises soil and water. Energy resources can be divided into the fossil fuels (crude oil, natural gas, coal, oil shale and tar sand) and the nuclear fuels (including uranium, thorium and geothermal power). Metal resources range from structural metals such as iron, aluminium and titanium to ornamental and industrial metals such as gold, platinum and gallium. Industrial minerals include more than 30 commodities, such as salt, asbestos and sand.

Mineral deposits have two geological characteristics that make them a real challenge to modern civilisation. First, almost all of them are non-renewable resources. The geological processes that form them are much slower than the rate at which we exploit them. There is no likelihood of our ability to grow mineral deposits at a rate equal to our consumption. Second, mineral deposits have a place value. We cannot decide where to extract them ; nature made that decision for us when the deposits were formed.

Question 14. 
Which elements constitute the earth?
Answer: 
The earth is composed of various kinds of elements. These elements are in solid form in the outer layer of the earth and in hot and molten form in the interior. About 98 per cent of the total crust of the earth is composed of eight elements like oxygen, silicon, aluminium, iron, calcium, sodium, potassium and magnesium, and the rest is constituted by titanium, hydrogen, phosphorus, manganese, sulphur, carbon, nickel and other elements.

Major elements of the earth’s crust

Elements	By weight (%)
1. Oxygen	46.60
2. Silicon	27.72
3. Aluminium	8.13
4. Iron	5.00
5. Calcium	3.63
6. Sodium	2.83
7. Potassium	2.59
8. Magnesium	2.09
9. Others	1.41

Comparison Questions

Question 1. 
Distinguish between Igneous Rocks and; Sedimentary Rocks.
Answer:

Igneous Rocks	Sedimentary Rocks
1. These rocks are massive and found in bulks.	1. These rocks occur in lay- ers or strata.
2. These rocks have different types of crystals.	2. These rocks contain minute particles.
3. These rocks are formed due to the cooling of magma.	3. These rocks are formed by deposition of sedi-ments.
4. These are hard and resistant rocks.	4. These are soft rocks.
5. These rocks do not contain fossils.	5. These rocks contain fos- sils of animals and plants.
6. These are also known as Primary rocks.	6. These rocks are known as Secondary rocks.
7. These rocks are not easily eroded due to weathering.	7. These rocks are easily eroded due to weather-ing.
8. These have a well- developed	8. These rocks have no joints.
9. These are impervious rocks.	9. These are pervious rocks.
10. These rocks are formed in volcanic regions.	10. These rocks are formed in depressions, seas, lakes.

Question 2. 
Distinguish between :

1. Rock and Mineral 
2. Limestone and Coal. Answer:

Rock	Mineral
1. Rock is an aggregate of minerals.	1. Mineral contains only one ore.
2. A rock is a natural solid material forming the earth crust.	2. A mineral is a natural inorganic compound found in the rocks.
3. Rocks are mainly of three types : Igneous, Sedimentary and Metamorphic.	3. There are about 2000 types of minerals.
4. A rock does not have a definite chemical composition.	4. It has a definite chemical composition.

 

Limestone	Coal
1. Limestone is a calcareous rock.	1. Coal is a carbonaceous rock.
2. It has been formed by remains of microscopic animals on the sea floor.	2. It is formed by the vegetation buried in swamps and forests.
3. Due to presence of cementing materials, it takes a solid shape.	3. Due to pressure of overlying sediments, the remains of plants are changed into carbon.

Question 3. 
Distinguish between Intrusive Rocks and Extrusive Rocks.
Answer:

Intrusive Rocks	Extrusive Rocks
1. Intrusive rocks are formed beneath the surface of the earth.	1. Extrusive rocks are formed on the surface of the earth.
2. These rocks have large size crystals due to slow cooling of lava.	2. Crystals are not formed due to rapid cooling of lava.
3. These are also known as plutonie rocks.	3. These are also known as volcanic rocks.
4. Granite is an example of these rocks.	4. Basalt is an example of these rocks.

Essay Type Questions

Question 1
Describe the main physical characteristics of minerals.
Answer: 
Some main physical characteristics of minerals
1. External crystal form-determined by internal arrangement of the molecules-cubes, octahedrons, hexagonal prisms, etc.

2. Cleavage-tendency to break in given directions producing relatively plane surfaces; result of internal arrangement of the molecules may cleave in one or more directions and at any angle to each other.

3. Fracture-internal molecular arrangement is so complex that there are no planes of molecules; the crystal will break in an irregular manner, not along planes of cleavage.

4. Lustre-appearance of a material without regard to colour; each mineral has a distinctive lustre like metallic, silky, glossy etc.

5. Colour-some minerals have characteristic colour determined by their molecular structure-malachite, azurite, chalcopyrite, etc. and some minerals are coloured by impurities. For example, because of impurities, quartz may be white, green, red, yellow, etc.

6. Streak-colour of the ground powder of any mineral. It may be of the same colour as the mineral or may differ-malachite is green and gives green streak; fluorite is purple or green but gives a white streak.

7. Transparency-transparent light rays pass through so that objects can be seen plainly; translucent-light rays pass through but will get diffused so that objects cannot be seen; opaque-light rays will not pass at all.

8. Structure-particular arrangement of the individual crystals; fine, medium or coarse grained; fibrous-separable, divergent, radiating.

9. Hardness-relative resistance being scratched; ten minerals are selected to measure the degree of hardness from 1 to 10. They are : 

• talc
• gypsum
• calcite
• fluorite
• apatite
• feldspar
• quartz 
• topaz
• corundum 
• diamond. Compared to this, for example, fingernail is 2.5 and glass or knife blade is 5.5.

10. Specific gravity-the ratio between the weight of a given object and the weight of an equal volume of water; object weighed in air and then weighed in water and divide weight in air by the difference of the two weights.

Source Based Questions

1. Read the following paragraph and answer the questions given below:
The crust of earth is composed of rocks. A rock is an aggregate of minerals. Rocks may be hard or soft and are of different colours. Such as granite is hard, soapstone is soft, gabbro is black in colour, whereas quartzite can be milky white. Rocks do not have definite composition of mineral constituents. Feldspar and  quartz are the most common minerals present in the rocks. Petrology is called the science of rocks. A person who studies rocks in all their aspects is known as petrologist. There is a closer relationship between rocks and landforms, rocks and soils. There are different kinds of rocks such as igneous, sedimentary and metamorphic rocks.
(i) The earth’s crust is made up of
(a) Minerals 
(b) Rocks
(c) Gasses 
(d) All of these
Answer:
(b) Rocks

(ii) Which of the following is a soft rock?
(a) Granite 
(b) Soapstone
(c) Gabbro 
(d) Quartzite
Answer: 
(b) Soapstone

(iii) Which of the following is a common mineral found in rocks?
(a) Quartz 
(b) Granite
(c) Gabbro 
(d) None of these
Answer: 
(a) Quartz

(iv) What is the study of rocks called?
(a) Pedology 
(b) Petrolegy
(c) Petrology 
(d) None of these
Answer: 
(c) Petrology

2. Read the following paragraph and answer the questions given below:
Igneous rocks are called primary rocks as they form out of magma and lava from the interior of the earth. Igneous rocks can be changed into metamorphic. Some fragments form out of rocks when the earth’s surface is exposed to denudational agents. These fragments are transported and get deposited. These deposits turn into rocks through compaction. These are the source of sedimentary rocks. The crustal rocks once formed may be carried down into the interior of the earth through subduction process of crustal plates going down under another plate in zone of convergence.

(i) Which of the following is a primary rock?
(a) Igneous 
(b) Metamorphic
(c) Sedimentary 
(d) All of these
Answer: 
(a) Igneous

(ii) Which of the following is a crustal rock?
(a) Igneous 
(b) Metamorphic
(c) Sedimentary 
(d) All of these
Answer: 
(d) All of these

(iii) Which of the following is/are secondary rocks?
(a) Igneous 
(b) Metamorphic
(c) Sedimentary 
(d) Both (b) and (c) 
Answer: 
(d) Both (b) and (c)

(iv) Which of the following is a continuous process?
(a) Magma 
(b) Sedimentation
(c) Rock cycle 
(d) None of these
Answer: 
(c) Rock cycle 

HOTS QUESTIONS 

Question 1
What do you mean by foliation and ; Banded rocks? 
Answer: 
Foliation:
In metamorphic rocks, grains or minerals get arranged in layers or lines. This is called foliation. Banded

rocks:
Sometimes minerals or materials of different groups are arranged into alternating thin to thick layers, appearing in light and dark shades. Such a structure is called banded rocks. 

SELF EVALUATION TEST 

1. Define the term Rock. 
2. Name three main types of rocks. 
3. State one example of Plutonic rocks. 
4. What is grit? 
5. What does the term Batholith mean? 
6. What is meant by lithosphere? 
7. Name the different types of coal. 
8. Distinguish between Ferrous and non ferrous minerals. 
9. What is magma? 
10. Distinguish between Igneous rocks and Sedimentary rocks.