8th Social - Rocks and Soil Answers

 Answers

I. Choose the correct answer:

1. Which of the following is known as sphere of rocks
a) Atmosphere
b) Biosphere
c) Lithosphere
d) Hydrosphere
Answer:
(c) Lithosphere

2. World soil day is observed on
a) 15th August
b) 12th January
c) 15th October
d) 5th December
Answer:
(d) 5th Decembe

3. Fossils are found in
a) Sedimentary rocks
b) Igneous rocks
c) Metamorphic rocks
d) Plutonic rocks
Answer:
(a) Sedimentary rocks

4. The top layer of soil is called as
a) organic layer or humas
b) topsoil
c) subsoil
d) bedrock
Answer:
(b) topsoil

5. Ideal soil for growing cotton is
a) Red soil
b) Black soil
c) Alluvial soil
d) Mountain soil
Answer:
(b) Black soil

6. The major components of soil is
a) Rocks
b) Minerals
c) Water
d) All the above
Answer:
(b) Minerals

7. Which one of the following is the most widespread most and productive category of soil
a) Alluvial soil
b) Black soil
c) Red soil
d) Mountain soil
Answer:
(a) Alluvial Soil

II. Fill in the blanks.

1. Scientific study of rocks is called …………….
Answer:
Petrology

2. ……………. soil is highly suitable for millets cultivation.
Answer:
Black

3. The “Skin of earth” is
Answer:
Soil

4. ……………. is the kind of metamorphic rock using which Taj Mahal was built.
Answer:
White marble

5. ……………. is known as the primary rocks.
Answer:
Igneous rock

True or False:

1. Igneous rocks are called primary rocks.
Answer:
True

2. Slate is formed from shale.
Answer:
True

3. Red soil is formed by the process of leaching.
Answer:
False

4. M-sand is used as alternative for natural sand in construction.
Answer:
True

5. Volcanic mountains are covered with sedimentary rocks.
Answer:
True

IV. Match the following:
1.Answer:
A) 2 14 3

2.Ans: D) 3, 1, 4, 2

V. Choose the incorrect statement from the following:

1. a) Igneous rocks are called the primary rocks.
b) Soil is the product of weathering of rocks.
c) Sedimentary rocks are the hardest ones.
d) Deccan plateau is the region of Igneous rocks.
Answer:
d) Deccan plateau is the region of Igneous rocks.

2. a) Soil erosion decreases its fertility.
b) Dynamic metamorphism is caused by high temperature.
c) Soil is a renewable source.
d) Humus is a part of the top layer of soil.
Answer:
c) Soil is a renewable source.

VI. Consider the. following statements and choose the right option from the given ones:
Statement (1): Sedimentary rocks consist of many layers.
Statement (2) : Sedimentary rocks are formed by the sediments deposited at different points of time.
(a) 1 and 2 are correct and 2 explains 1
(b) 1 and 2 are correct but, 2 does not explain 1
(c) 1 is correct but, 2 is incorrect
(d) 2 is correct but, 1 is incorrect.
Answer:
(a) 1 and 2 are correct and 2 explains 1

Additional Important Questions and Answers

I. Choose the Correct answer.
1. Petrology is derived from the ………….. word.
a) English
b) Latin
c) Greek
d) French
Answer:
(c) Greek

2. The soils found in the desert regions are …………..
a) Mountain Soils
b) Desert Soils
c) Black Soil
d) Red Soil
Answer:
(b) Desert Soils

3. Which Soils are formed by the weathering of metamorphic rocks?
a) Red Soils
b) Rock Soils
c) Laterite Soils
d) Mountain Soils
Answer:
(a) Red Soils

4. …………….. is a part composed of organic matter mixed with mineral matter.
a) Humus
b) Top Soil
c) Elevated layer
d) Sub-soil
Answer:
(b) Top Soil

5. The time to form one cm of soil is
a) 100 years
b) 200 years
c) 500 years
d) 1000 years
Answer:
(b) 200 years

6. …………….is known as the zone of accumulation.
a) Humus
b) Top Soil
c) Elevated layer
d) Sub-soil
Answer:
(d) Sub-soil

7. In the soil composition ………….. are minerals.
a) 5%
b) 10%
c) 25%
d) 45%
Answer:
(d) 45%

8. In the soil composition is air.
a) 5%
b) 10%
c) 25%
d) 40%.
Answer:
(c) 25%

9. ……………. soils are formed by the deposition of silt by the running water.
a) Black
b) Red
c) Alluvial
d) Desert
Answer:
(c) Alluvial

10. the Soil composition is organic matter.
a) 5%
b) 10%
c) 25%
d) 45%
Answer:
(a) 5%

II. Fill in the blanks:
1. A rock is an aggregate of ………….. or more minerals.
Answer:
one

2. There are ………….. different types of minerals found on the earth Surface.
Answer:
2000

3. Rocks are classified in to ………….. types.
Answer:
three

4. The two types of Intrusive Igneous rocks are ………….., …………..
Answer:
Plutonic rocks, Hypabysal rocks

5. Igneous Rocks are ………….. rocks
Answer:
Primary

6. ……………. into slate caused by thermal metamorphism.
Answer:
Basalt

7. Soil is a basic requirement for the growth of ………….. and …………..
Answer:
Plants, animals

8. To become a well-matured soil, it takes about ………….. years.
Answer:
3000

9. Parent Rock is converted to loose Rock by ……………
Answer:
soil

10. Laterite soil is suitable for plantation crops like ………….., …………..
Answer:
tea, coffee

III. State whether the following statements are true or false:

1. To become a well-matured soil, it taken about 2000 years.
Answer:
False

2. Lava comes out from a volcano.
Answer:
True

3. The word Ignis means rock.
Answer:
False

4. Oldest Sedimentary rocks of the world has been identified in Green land.
Answer:
True

5. Soil supports ecosystem and play an important role in land management.
Answer:
True

IV. Match the following:
1.

Answer:
D) 3 1 4 2

V. Choose the incorrect statement from the following:
1. a) Basalt into slate caused by thermal metamorphism.
b) Chemical Sedimentary rocks are also called evaporates.
c) Taj Mahal in India was built with white marbles of Sedimentary rocks.
d) Rocks have been used by mankind throughout history.
Answer:
c) Taj Mahal in India was built with white marbles of Sedimentary rocks.

VI. Consider the following statements and choose the right option from the given ones:
1. Statement (1): Petrology is a branch of geology.
Statement (2): It deals with the Study of water researches.
a) 1 and 2 are correct and 2 explains 1
b) 1 and 2 are correct but, 2 does not explain 1
c) 1 is correct but, 2 is incorrect
d) 2 is correct but, 1 is incorrect.
Answer:
c) 1 is correct but, 2 is incorrect