Tamilnadu Samacheer Kalvi 7th Social Science Geography Solutions Term 1 Chapter 2 LandForms
Samacheer Kalvi 7th Social Science LandForms Textual Evaluation
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7th
Std Term-1
I. Choose the correct answer:
Question 1.
is a deposition of river sediments along the foot-hills.
(a) Plunge pool
(b) Alluvial fan
(c) Floodplain
(d) Delta
Answer:
(b) Alluvial fan
Question 2.
Courtallam falls is
located across the river.
(a) Cauvery
(b) Pennar
(c) Chittar
(d) Vaigai
Answer:
(c) Chittar
Question 3.
The landform created by glacial deposition is
(a) Cirque
(b) Arete
(c) Moraine
(d) Tam lake
Answer:
(c) Moraine
Question 4.
Large deposits of loess are found in
(a) USA
(b) India
(c) China
(d) Brazil
Answer:
(c) China
Question 5.
are not associated with wave erosion
(a) Cliff
(b) Sea arch
(c) Stack
(d) Beaches
Answer:
(d) Beaches
II. Fill in the Blanks
1.The process of breaking and crumbling
of rocks is weathering
2.The place where the river joins a lake
or a sea is known as river mouth
3.Inselbergs are
found in the Kalahari desert in South Africa.
4.A cirque is known as Kar in
Germany.
5.The first longest beach in the world is
Miami
III. Match the following
1. Breaking and crumbling
of rocks - Weathering
2. Abandoned meander
loops - Oxbow lake
3. Large body of moving
ice -
Glacier
4. Crescent shaped sand
dunes
- Barchans
5. Vembanad lake - Lagoon
IV. Consider the following statement
and (✓) Tick the appropriate answer.
Question 1.
Assertion (A) : The deltas are formed near the mouth of the river.
Reason (R) : The velocity of the river becomes slow when it approaches the
sea.
(a) Both A and R are correct
(b) A is correct and R is wrong
(c) A is wrong and R is correct
(d) Both A and R are wrong
Answer:
(a) Both A and R are correct
Question 2.
Assertion (A) : Sea arches in turn become Sea Stacks.
Reason (R) : Sea Stacks are the results of wave deposition.
(a) Both A and R are correct
(b) A is correct and R is wrong
(c) A is wrong and R is correct
(d) Both A and R are wrong
Answer:
(b) A is correct and R is wrong
V. Answer the following.
Question 1.
Define
erosion.
Answer:
Erosion is the wearing away of the landscape by different agents like water,
wind, ice and sea waves.
Question 2.
What is
a plunge pool?
Answer:
Plunge pool is a hollow feature at the base of a waterfall which is formed by cavitation.
Question 3.
How are
Ox – bow lakes formed?
Answer:
Due to continuous erosion and deposition along the sides of the meander, the
ends of the meander loop comes closer and closer. In due course of time the
meander loop cuts off from the river and forms a cutoff lake, also called an
Ox-bow lake.
Question 4.
Name
the major landforms formed by glacial erosion.
Answer:
Cirque, Aretes, U’
Shaped Valley
Question 5.
Give a
note on Mushroom rocks.
Answer:
In deserts rocks in the shape of a mushroom, commonly called mushroom rocks.
Question 6.
What is
a lagoon? Give an example.
Answer:
Lagoon is a shallow stretch of water partially or completely separated from the
sea.
E.g. Chilka lake in Odisha, Pulicat lake in
Tamil Nadu and Andhra Pradesh and Vembanad lake in
Kerala are the famous lagoons in India.
VI. Distinguish between
Question 1.
Tributary and Distributary
Answer:
Question 2.
‘V’ shaped valley and ‘U’ shaped valley
Answer:
Question 3.
Continental glacier and Mountain glacier
Answer:
VII. Give reason
Question 1.
The ends of the meander loops come closer and closer.
Answer:
Due to continuous erosion and deposition of rivers along the sides of the
meander, the ends of the meander loop comes closer and closer.
Question 2.
Flood plains are very fertile.
Answer:
At times the river overflows its banks. This leads to the flooding of the
neighbouring areas. As the river floods, it deposits layers of fine soil and
other material called sediments along its banks. This leads to the formation of
a flat fertile floodplain.
Question 3.
Sea caves are turn into stacks.
Answer:
As the cavities of sea caves become bigger, only the roof of the caves remain
to form sea Arches. When erosion further breaks the roof, only walls are left,
thus forming stacks.
VIII. Answer in a paragraph
Question 1.
Explain different landforms produced by river erosion. Answer:
The running water in the river erodes
the landscape, which creates a steep-sided valley like the letter ‘V’ known as
‘V’ shaped valley.
Falling of river water over a vertical
step in the river bed is called waterfall. It is formed when the soft rocks are
removed by erosion. E.g. Coutrallam falls
across the river Chittar in Tamil
Nadu.
Plunge
pool is a hollow feature at the base of a waterfall which is formed by
cavitation. Alluvial fan is a deposition of sediment occurs at which the river
enters a plain or the foot-hills.
As the
river enters the plain it twists and turns forming large bends known as
Meanders.
Eg. Meanders along the River Vellar near Sethiyathope in Cuddalore District,
Tamil Nadu.
Due to
continuous erosion and deposition along the sides of the meander, the ends of
the meander loop comes closer and closer. In due course of time the meander
loop cuts off from the river and forms a cutoff lake, also called an Ox-bow
lake.
Question 2.
Describe the landforms associated with wind.
Answer:
Winds erode the lower section of the
rock more than the upper part.
An isolated residual hill, standing
like a pillar with rounded tops are called Inselbergs.
E.g. Inselberg in the
Kalahari Desert of South Africa.
When the
wind blows, it lifts and transports sand from one place to another. When it
stops blowing the sand falls and gets deposited in low hill – like structures.
These are called sand dunes. The crescent shaped sand dunes are called
Barchans.
When the
grains of sand are very fine and light, the wind can carry it over very long
distances. When such sand is deposited in large areas, it is called Loess.
Large deposits of loess are found in China.
Question 3.
How are aretes formed?
Answer:
Glaciers
erode the landscape by levelling soil and stones to expose the solid rock
below.
Cirque is
a glacially eroded rock basin, with a steep side wall and steep head wall,
surrounding an armchair-shaped depression.
As the
ice melts, they get filled up the cirque with water and become beautiful lakes
in the mountains called as Tam Lake. When two adjacent cirques erode towards
each other, the previously rounded landscape is transformed into a narrow
rocky, steep – sided ridge called Aretes.
Activity
Question 1.
Fill in the corresponding columns with reference to the landform features given
below
Answer:
Barchan, ‘V’
Shaped valley, Cliff, Arete, Inselberg,
Moraine, Alluvial fan, Lagoon
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