Drainage System

The correct sequence of the tributaries joining the Ganga from West to East is Gomati - Ghaghara - Gandak - Kosi.

Gomati: It is a plains-fed river that originates from Gomat Taal (Fulhaar Jheel) in the Pilibhit district of Uttar Pradesh. It joins the Ganga near Varanasi.

Ghaghara: It originates in the Mapchachungo glaciers near Mansarovar in Tibet. It flows through Nepal before joining the Ganga at Chhapra, Bihar.

Gandak: It rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest. It enters the Ganga plain in Bihar and joins the Ganga at Sonpur near Patna.

Kosi: Known as the 'Sorrow of Bihar', it originates in the Himalayas (Tibet/Nepal) and joins the Ganga near Kursela in the Katihar district of Bihar.

Statement 1 is Correct: The Jhelum River, which originates from the Verinag Spring in the Kashmir Valley, flows through Srinagar and enters the Wular Lake before continuing its course towards Baramulla.

Statement 2 is Incorrect: Kolleru Lake is located between the deltas of the Krishna and Godavari rivers in Andhra Pradesh. It is not directly fed by the main Krishna River; instead, it receives water from seasonal streams such as the Budameru and Tammileru, which are independent inflows and not distributaries of the Krishna or Godavari systems.

Statement 3 is Incorrect: Kanwar Lake (also known as Kabartal) in Bihar is an oxbow lake formed by the meandering of the Burhi Gandak River. The Burhi Gandak is a separate river system that flows parallel to the main Gandak River.

Pair 1 is not correctly matched. Ghataprabha Reservoir Located in Karnataka, not Telangana.

Pair 2 is correctly matched. Gandhi Sagar Reservoir Located in Madhya Pradesh (correctly matched).

Pair 3 is not correctly matched. Indira Sagar Reservoir Located in Madhya Pradesh, not Andhra Pradesh.

Pair 4 is not correctly matched. Maithon Reservoir Located in Jharkhand, not Chhattisgarh.


Statement 1 is Incorrect: The Brahmani river is formed by the confluence of the Sankh and South Koel rivers near Rourkela; these headstreams originate in the Chota Nagpur Plateau of Jharkhand, not the Eastern Ghats.

Statement 2 is Correct: The Nagavali river (also known as Langulya) originates in the Eastern Ghats near Lakhbahal in the Kalahandi district of Odisha.

Statement 3 is Incorrect: The Subarnarekha river originates in the Chota Nagpur Plateau near Ranchi in Jharkhand and flows through West Bengal and Odisha before entering the Bay of Bengal.

Statement 4 is Correct: The Vamsadhara river originates in the Eastern Ghats near Lanjigarh in the Kalahandi district of Odisha and flows through Andhra Pradesh before joining the Bay of Bengal.

The common feature among the places Aliyar, Isapur and Kangsabati is that they are all known for their water reservoirs.

- Aliyar Reservoir is located in Aliyar village, Tamil Nadu. - Isapur Dam is an irrigation project in Maharashtra. - Kangsabati Dam is located on the Kangsabati River in West Bengal.


Kodaikanal Lake, also known as Kodai Lake is a manmade lake located in the Kodaikanal city in Dindigul district in Tamil Nadu, India.

Sir Vere Henry Levinge, the then Collector of Madurai, was instrumental in creating the lake in 1863, amidst the Kodaikanal town which was developed by the British and early missionaries from the USA.


Statement 1 is Incorrect: The Teesta River originates from the Pahunri (or Teesta Kangse) glacier and Tso Lhamo Lake in North Sikkim. In contrast, the Brahmaputra River originates from the Angsi Glacier (or Chemayungdung Glacier) in the Kailash range of Tibet. Therefore, their sources are not the same.

Statement 2 is Correct: The Rangeet River originates from the Rathong Glacier in West Sikkim. It is the largest tributary of the Teesta River and joins it at Melli, near the border of Sikkim and West Bengal.

Statement 3 is Incorrect: After flowing through Sikkim and West Bengal, the Teesta enters Bangladesh and joins the Brahmaputra River (known as the Jamuna in Bangladesh) at Fulchhari. It does not flow directly into the Bay of Bengal, nor does it reach the sea on the India-Bangladesh border.

Hence, option B is the correct answer.

Statement 1 is Correct: The Dibang River is a major left-bank tributary of the Brahmaputra that flows through the Mishmi Hills in Arunachal Pradesh before joining the main river. Statement 2 is Correct: The Kameng River is a significant right-bank tributary of the Brahmaputra; it originates in the Tawang district of Arunachal Pradesh and flows through the Kaziranga area. Statement 3 is Correct: The Lohit River is an important left-bank tributary that originates in eastern Tibet and flows through the Mishmi Hills of Arunachal Pradesh to join the Brahmaputra in the Assam valley.


India took a step forward in its ambitious but long-pending goal to interlink major rivers to form a national water grid. The Pattiseema project lifts flood water from the river Godavari and pumps it into the Polavaram right canal that empties into the river Krishna in Vijayawada.

Andhra Pradesh Government is interlinking Krishna-Godavari rivers through the Pattiseema lift irrigation scheme.

Hence, option B is the correct Answer.

Indravati and Pranhita: These are major left-bank tributaries of the Godavari River.


Vamsadhara: This river flows independently into the Bay of Bengal and is not a tributary of Godavari.

Pennar: This river flows entirely within Andhra Pradesh and drains into the Bay of Bengal south of Chennai. It's not a tributary of Godavari.

The Sutlej is the river that joins the Indus directly after receiving the collective drainage of the other three rivers. According to NCERT Class 11 (India: Physical Environment), the Jhelum and Ravi rivers join the Chenab, and the Chenab subsequently joins the Sutlej in Pakistan. The Sutlej then flows into the Indus a few kilometres above Mithankot. Thus, the Sutlej acts as the final conduit for the combined waters of the Jhelum, Ravi, and Chenab before their confluence with the Indus. This geographical sequence is confirmed by the official UPSC Answer Key for the 2021 Prelims, which identifies Option D as the correct answer.

Gandikota is a small village in the Kadapa district of Andhra Pradesh. The village is majorly known for housing the spectacular gorge which is famously adjudged as the "Grand Canyon of India".

The canyon is a gorge carved out over millions of years by the Pennar River that streams from the Erramala hills.

It's known for its red-hued, layered, and jagged rock formations.


Barak: The Barak River is important in Manipur and Mizoram, but it does not flow through Arunachal Pradesh.

Lohit: The Lohit River originates in the eastern end of the Himalayas in the Mishmi Hills of Arunachal Pradesh and flows through the districts of Anjaw, Lohit, and Dibrugarh in Arunachal Pradesh.

Subansiri: The Subansiri River is a tributary of the Brahmaputra River and flows through Arunachal Pradesh.

Therefore, only the Lohit and Subansiri rivers flow through Arunachal Pradesh.

Option (B) 2 and 3 only

Statement 1 is correct: The Narmada River flows through a linear rift valley, formed due to faulting and subsidence between two upland regions — the Vindhya Range (north) and the Satpura Range (south). This tectonic feature directs the river's flow toward the west.

Statement 2 is incorrect: The river indeed flows between the Vindhyas and the Satpuras, following the east–west oriented rift valley, But do not adequately explain why Narmada flows westward. Confinement could lead a river to flow in either direction.

Statement 3 is incorrect: The general slope of the Peninsular Plateau is from west to east, which is why most peninsular rivers (like Godavari, Krishna, and Mahanadi) flow eastward into the Bay of Bengal. The Narmada's westward flow is an exception due to its rift valley structure, not due to land slope.