Hydrosphere

Samacheer Book Back Questions And Answers For Geography Standard 9 Full Book “Hydrosphere”

I Choose the correct answer:
1. The Sunda Trench lies in the ___________ ocean.
a) Atlantic
b) Pacific
c) Indian
d) Antarctic

2. The temperature of the ocean waters generally_______ at greater depth.
a) increases
b) decreases
c) remains constant
d) none of the above

3. Ocean currents are produced due to _________
a) due to rotation of earth
b) due to variation in temperature
c) due to earth’s movement
d) all the above

4. Consider the following statements.
1. Most of the fishing grounds occur in areas where the continental shelf is wide.
2. Fishing is well developed in warm tropical waters.
3. Mixing of warm and cold currents facilitates plant nutrients for fish.
4. Inland fishing became significant in India.
a) 1 and 2 are correct.
b) 1 and 3 are correct.
c) 2,3 and 4 are correct.
d) 1,2 and 3 are correct

5. The oceanic ridge comes into existence due to
a) convergence of tectonic plates
b) divergence of tectonic plates
c) lateral movements of plates
d) stearing of plates

6. Which of the following indicates the correct sequence of the topography beneath the surface of the sea?
a) Continental shelf-Continental slope- Sea plain-Sea trench.
b) Continental slope-Continental shelf- Sea plain-Sea trench.
c) Sea plain-Continental slope- Continental shelf-Sea trench.
d) Continental slope-Sea plain- Continental shelf-Sea trench.

7. Which of the following is not correctly matched?
a) Gulf Stream – Pacific ocean
b) Labrador current – North Atlantic ocean
c) Canary current – Mediterranean sea
d) Mozambique current – Indian Ocean

Answers:
(a) Gulf Stream – Atlantic Ocean

II. Questions are of Assertion(A), Reason (R) type:
a) Both A and R are correct and R explains A.
b) Both A and R are correct but R does not explain A.
c) A is correct but R is false.
d) A is false but R is correct

1. Assertion (A): Oceans are always shown in blue in maps.
Reason(R): It indicates the natural colour of the oceans.
Answers:
Both A and R are correct and R explains A.

2. Assertion(A): Flat topped seamounts are known as Guyots.
Reason(R): All guyot features are of volcanic origin.
Answers:
A is correct but R is false.

3. Assertion(A): Submarine canyons are deep gorges on the ocean floor.
Reason(R): They are mainly restricted to continental shelf, slope and rise
Answers:
Both A and R are correct but R does not explain A.

4. Assertion (A): Atolls are more common in the Atlantic ocean.
Reason(R): The marine population at the depth is less.
Answers:
Both A and R are correct and R explains A.

III. Match the following:
1. Mariana trench           A. Decreases the salinity in the oceans
2. Great Barrier Reef       B. Along the coast of japan
3. Sargasso sea              C. Deepest point in the pacific
4. Spring tides               D. Australia
5. Heavy rains                E. Second order landform
6. Kuroshio current        F. North Atlantic Ocean
7. Continental slope      G. On full and new moon days

Answers:
1. C
2. D
3. F
4. G
5. A
6. B
7. E