Daily Challenge
Thursday, 8 October 2026
Daily Challenge — 8 October 2026
Three UPSC Prelims-pattern questions — one each from the GS I, GS II and GS III subject areas. Attempt all three before checking your answers.
The Universe and the Earth
Consider the following statements:
- The Moon always shows the same face to the Earth because its periods of rotation and revolution are equal.
- A lunar eclipse can occur only on a full moon day.
- A solar eclipse can occur only on a full moon day.
Which of the statements given above are correct?
Correct answer: A
Statement 1 is correct: synchronous rotation (about 27.3 days for both rotation and revolution) keeps one face towards the Earth. Statement 2 is correct: a lunar eclipse needs the Earth between the Sun and the Moon, which happens only at full moon. Statement 3 is wrong: a solar eclipse needs the Moon between the Sun and the Earth, which happens only at new moon.India and its Neighbourhood
Which one of the following Indian States shares an international border with both Nepal and Bhutan?
Correct answer: A
Sikkim borders Nepal to the west, Bhutan to the east and China to the north. Assam and Arunachal Pradesh border Bhutan but not Nepal; Uttarakhand borders Nepal but not Bhutan. (West Bengal also borders both, but it is not among the options.)Ecology and Ecosystems
Consider the following statements about ecological succession:
- Primary succession begins in areas where no soil exists.
- Secondary succession is generally faster than primary succession.
- Lichens are the pioneer species in hydrarch succession.
Which of the statements given above is/are correct?
Correct answer: B
Statement 1 is correct: primary succession starts on bare rock, lava or sand with no soil. Statement 2 is correct: secondary succession starts where soil already exists, so it is faster. Statement 3 is wrong: lichens pioneer xerarch succession on bare rock; in hydrarch (water) succession the pioneers are phytoplankton.