UPSC Prelims 2026 · GS Paper I: Consider the following assertion :In the Pleistocene period either the Yamuna once flowed into…
Consider the following assertion :
In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa.
Which of the following is/are the basis of the above assertion ?
- 1. The Nadi-Sukta of the Rigveda
- 2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote
- 3. The presence of the same species of dolphins in both the Indus and the Ganga river systems
Select the answer using the code given below :
Answer (d) & explanation
Only the dolphin evidence is a basis (d). Item 3 is right: the Indus and Ganga river dolphins are so close that they were long treated as one species, which only makes sense if the two river systems were once joined. Item 1 is wrong: the Pleistocene ended about 12,000 years ago, long before the Rigveda, so the Nadi-Sukta cannot be evidence for it. Item 2 is wrong: Robert Bruce Foote worked on the stone ages of South India, not these rivers.
Notice the Ganges river dolphin is India's national aquatic animal, and is nearly blind, using echolocation. Project Dolphin (2020) protects it. The Indus dolphin lives mainly in Pakistan, with a small group in the Beas in Punjab.
Answer as per the official UPSC answer key.
Same theme in UPSC Mains
Related questions from other years
Consider the following statements about the Rigvedic period :
- I. Irrigation from wells allowed agriculture to expand away from flood plains and strips on river margins into the present Punjab and Haryana plains having underground water levels reasonably close to the surface.
- II. Draught-animal power was employed to draw up water out of the wells.
Which of the following information support/supports the above statements ?
- 1. There is evidence in the Rigveda of the use of ashma chakra (stone pulley wheel) and ahava (strapped wooden pails) to draw up water.
- 2. Mention has been made in the Rigveda of the use of implements like parashu/ kulisha (axe) and datra /sreni (sickle).
- 3. There is a history of the use of ox, even before the Rigveda, for ploughing the land and pulling the carts.
Select the answer using the code given below :
Answer (c) & explanation
Information 1 and 3 support the statements (c). Item 1 is right: the ashma chakra (stone pulley wheel) and ahava (strapped wooden pails) of the Rigveda show water being lifted from wells, which supports Statement I. Item 3 is right: the ox was already used for ploughing and pulling carts before the Rigveda, so animal power was available to lift water, which supports Statement II. Item 2 is wrong: axes and sickles are farm tools, but they say nothing about wells or irrigation.
Notice the method: in such questions, ask whether each fact directly supports the claim, not just whether it is true. The Rigvedic economy was mainly pastoral, with cattle as wealth (gavishti, the search for cows, meant war). Iron and big farming came later.
Statement 2 is true, but it does not support either statement. "Supports" questions test relevance, not truth.
Answer as per the official UPSC answer key.
Which of the following pairs of ancient and modern names of rivers is/are correctly matched ?
- 1. Vitasta : Chenab
- 2. Asikni : Jhelum
- 3. Parushni : Ravi
- 4. Yavyavati : Beas
Select the answer using the code given below :
Answer (c) & explanation
Only pair 3 is correctly matched (c). In the Rigveda, Parushni = Ravi, so pair 3 is right. Pairs 1 and 2 are swapped: Vitasta = Jhelum, and Asikni = Chenab. Pair 4 is wrong: Yavyavati is usually taken as the Zhob, a western river; the Beas is the Vipas. So options (a), (b) and (d) fail.
Notice the full list: Shutudri = Sutlej, Sindhu = Indus, Kubha = Kabul, Gomati = Gomal, and Sarasvati, often linked to the Ghaggar-Hakra. The Battle of Ten Kings (Dasarajna), won by Sudas of the Bharatas, was fought on the Parushni. These rivers form the "Sapta Sindhu" region.
Pairs 1 and 2 swap the right names, which catches a hurried reader.
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Answer as per the official UPSC answer key.
Which of the following pairs of the king and his dynasty in early historical Tamilakam is/are not correctly matched ?
- 1. Senguttuvan : Chera
- 2. Udiyanjeral : Chola
- 3. Nedunjeliyan : Pandya
Select the answer using the code given below :
Answer (b) & explanation
Only pair 2 is not correctly matched (b). The Sangam poems name three crowned houses: Chera, Chola and Pandya. Pair 1 is correct: Senguttuvan, hero of the Kannagi cult, was a Chera. Pair 3 is correct: Nedunjeliyan, the victor of Talaiyalanganam, was a Pandya. Pair 2 is wrong: Udiyanjeral was a Chera, not a Chola; "-jeral" is a Chera ending. So the answer is pair 2 only.
Notice the trap: the question asks which is not correctly matched. Senguttuvan's story is told in Silappadikaram. Karikala is the most famous early Chola, linked to the Kallanai dam. The Pathitrupathu sings of Chera kings, and Madurai was the Pandya seat.
This one asks for "not correctly matched". Mark the wrong pair, not the right ones.
Answer as per the official UPSC answer key.
What does an empty seat represent in early Buddhist iconography ?
Answer (a) & explanation
An empty seat represents the Buddha's meditation (a). Early Buddhist art at Bharhut and Sanchi does not show the Buddha in human form. Symbols stand in for him: an empty seat, often under the Bodhi tree, for his meditation and enlightenment. Option (b) is wrong: a wheel stands for the First Sermon at Sarnath. Option (c) is wrong: a stupa stands for the Mahaparinibbana, his death. Option (d) is wrong: a horse stands for the Great Departure (Mahabhinishkramana).
Notice the later change: the Gandhara and Mathura schools, under the Kushanas, first showed the Buddha as a human. Other symbols: a lotus or elephant for his birth, and footprints for his presence. This early stage is called aniconic.
The key follows UPSC's provisional key. The usual symbol table pairs each event with a different sign, so learn all four together.
Answer as per the official UPSC answer key.
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