NCERT Solutions for Class 9 Social Science Geography Chapter 3 Drainage

Q. Which of the following Peninsular rivers is called the ‛Dakshin Ganga’?
(a) Mahanadi
(b) Krishna
(c) Godavari
(d) Tapi

Ans. (c) Godavari

Q. Which of the following is odd one?
(a) Delhi
(b) Ambala
(c) Allahabad
(d) Kolkata

Ans. (b) Ambala

Q. Which one of the following lakes is a salt water lake?
(a) Sambhar
(b) Dal
(c) Wular
(d) Gobind Sagar

Ans. (a) Sambhar

Q. The area drained by a single river system is called a _________ . 

Ans. Drainage

Q. The name of the place where the river Indus emerges out of the mountains to the plain is called Vishnu.

Ans. False

Q.

COLUMN-A COLUMN-B
(1) Drainage (a) Headwaters of the Ganga
(2) Drainage basin (b) Area drained by a single river system
(3) Bhagirathi (c) River system of an area
(4) Sambhar lake (d) Salt water lake

Options:
(a) (1)-(c), (2)-(b), (3)-(a), (4)-(d)
(b) (1)-(b), (2)-(c), (3)-(a), (4)-(d)
(c) (1)-(a), 2-(c), (3)-(d), (4)-(b)
(d) (1)-(d), 2-(b), (3)-(a), (4)-(c)

Ans. (a) (1)-(c), (2)-(b), (3)-(a), (4)-(d)

Q. What is drainage?

Ans. (a) (1)-(c), (2)-(b), (3)-(a), (4)-(d)

Q. Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?

Ans. Because the volume of water in Tibet is less, thus resulted in less erosion and less silt carrying capacity

Q. State any one difference between the Himalayan and the Peninsular rivers.

Ans. The Himalayan River : The Himalayan rivers are perennial in nature,means they flow throughout the year.
The Peninsular River : A large number of the Peninsular rivers are seasonal and their flow is dependent on rainfall

Q. Why do the Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts?

Ans. The Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts because these rivers are seasonal, even the large rivers have reduced flow of water in their channels.

Q. Explain the Ganga River System?

Ans. The Ganga River System :
(i) The Ganga acquires its water after its two headstreams—the Alaknanda and the Bhagirathi join at Devaprayag.
(ii) The Ganga enters the plains from the Himalayas at Haridwar.
(iii) It is joined by a large number of tributaries from the north. Among them the Ghaghara, the Gandak, and the Kosi enter the northern plains of India from Nepal.
(iv) They are the rivers, which flood parts of the northern plains every year, causing widespread damage to life, whereas, they enrich the soil for agricultural use.
(v) These rivers have tremendous potential to generate hydropower and to irrigate lands both in Nepal and India.
(vi) The length of the Ganga is over 2,500 km.
(vii) In India, it has the largest basin.

Q. Assertion (A) : The term drainage describes the river system of an area.
Reason (R) : The area drained by a single river system is called a drainage basin.

Ans. (a) Both A and R are true and R is the correct explanation of A.

 Explanation :

Drainage describes the river system of an area. It includes small streams flowing from different directions come together to form the main river, which ultimately drains into a large water body such as a lake or a sea or an ocean. Assertion talks about drainage system which is supported by reason that talks about drainage basin. So, both A and R are true, and R is the correct explanation of A.

Q. Assertion (A) : The Ganga plain extends between Ghaggar and Teesta rivers.
Reason (R) : It spreads over the Indian states of Haryana, Delhi, U.P., Bihar.
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.

Q. Assertion (A): The growing domestic, municipal, industrial and agricultural demand for water from rivers naturally affects the quality of water.
Reason (R) : Concern over rising pollution in our rivers led to the launching of various action plans to clean the rivers 
(a) Both A and R are true, and R is correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.