Which is the longest river flowing entirely within the territory of India?

The correct answer is C, Tons. The Tons is a tributary of the Yamuna in the Ganga system, rising in the Garhwal Himalaya, and has nothing to do with the Brahmaputra basin. Option A is wrong as an answer because the Teesta, which drains Sikkim and north Bengal, does join the Brahmaputra, doing so in Bangladesh. Option B is wrong because the Siang, also called the Dihang, is the name the Brahmaputra itself carries in Arunachal Pradesh and is treated as its head stream, so it belongs to the system. Option D is wrong because the Manas, which comes down from Bhutan through the Manas national park, is one of the major north-bank tributaries of the Brahmaputra in Assam. The other tributaries worth remembering are the Subansiri, the Kameng, the Dibang and the Lohit, the last two giving the river its Assam name at Sadiya.

The correct answer is D, Shipki La. The Sutlej rises from the Rakas lake near Mansarovar in Tibet, where it is called the Langchen Khambab, and enters India through the Shipki La pass in Himachal Pradesh before flowing on to join the Beas at Harike. Option A is wrong because Zoji La lies on the road from Srinagar to Kargil in Ladakh and carries no such river. Option B is wrong because Nathu La is a trade pass in Sikkim on the route to Tibet, in an entirely different part of the Himalaya. Option C is wrong because Lipulekh is a pass in Uttarakhand used by the Kailash Mansarovar pilgrimage and by the Kali river valley, not by the Sutlej. The Sutlej also carries the Bhakra Nangal project, so link the river, the pass and the dam together when you revise.

The correct answer is C, Parushni. In the Rigveda the Ravi appears as the Parushni, and it is on this river that the Battle of the Ten Kings, the Dasarajna, is placed. Option A is wrong because Askini, also written Asikni, is the Vedic name of the Chenab, which is formed by the Chandra and Bhaga streams and is also called the Chandrabhaga. Option B is wrong because Shutudri is the Vedic name of the Sutlej, the river that enters India through the Shipki La pass. Option D is wrong because Kalindi is an old name of the Yamuna, which rises at the Yamunotri glacier and joins the Ganga at Prayagraj. The remaining pairs to memorise are the Jhelum as the Vitasta and the Beas as the Vipasha, since papers often ask all six Punjab rivers in one matching question.

The correct answer is C, Krishna. The Musi rises in the Anantagiri hills of Telangana, flows through Hyderabad, and joins the Krishna in Nalgonda district, which is why the city's water supply and floods are tied to it. Option A is wrong because the main tributaries of the Kaveri are the Hemavati, the Kabini, the Bhavani, the Noyyal and the Amaravati. Option B is wrong because the Godavari receives the Indravati, the Manjra, the Purna, the Pranhita and the Wainganga, not the Musi. Option D is wrong because the Mahanadi, which rises in the highlands of Chhattisgarh and carries the Hirakud dam, is joined by the Seonath, the Hasdeo, the Jonk and the Tel. The Krishna's other tributaries are the Bhima, the Tungabhadra and the Ghatprabha, and the pair Hyderabad, Musi and Krishna is the quickest way to hold this fact.

The correct answer is C, Trimbakeshwar near Nashik. The Godavari rises in the Western Ghats at Trimbakeshwar in the Nashik district of Maharashtra and flows east across the peninsula to the Bay of Bengal, draining the second largest basin in India after the Ganga. Option A is wrong because the Amarkantak plateau in Madhya Pradesh is the source of the Narmada, and the Son also rises in the same highland. Option B is wrong because Talakaveri in the Brahmagiri hills of Karnataka is the source of the Kaveri. Option D is wrong because the Krishna rises near Mahabaleshwar in the Western Ghats of Maharashtra. All four places are standard options in this question, so fix each with its river: Trimbakeshwar with the Godavari, Mahabaleshwar with the Krishna, Talakaveri with the Kaveri and Amarkantak with the Narmada.