Climate & atmosphere

Answer: (b) Lake Faguibine

Lake Faguibine, near Timbuktu in northern Mali, was fed by overflow from the Niger. Droughts in the 1970s dried it, and sand then choked the channels from the river, so even when rains returned the water could not reach it; the lake bed has largely turned to desert.

• ✓ (b) UNEP reports that Lake Faguibine has been dry since the 1970s: droughts emptied the lake system and sand-filled channels cut it off from the Niger's floods.
• ✗ (a) Lake Victoria is in East Africa (shared by Uganda, Kenya and Tanzania), not West Africa, and it has not dried up.
• ✗ (d) Lake Volta in Ghana is a large artificial reservoir behind the Akosombo Dam and still holds water for hydropower; Lake Oguta in Nigeria is also a living lake.

Remember · Lake Faguibine (Mali, near Timbuktu): Niger-fed lake system dried since the 1970s droughts — a Sahel symbol of desertification; UNEP has worked on reviving it.

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) Second half of the month of June

The Northern Hemisphere's longest day is the summer solstice, around 21 June, when the North Pole is tilted most towards the Sun and the Sun is overhead at the Tropic of Cancer. 21 June falls in the second half of June.

• ✓ (b) The summer solstice falls on 20, 21 or 22 June; after it, days in the Northern Hemisphere grow shorter and nights longer.
• ✗ (a) Days are still lengthening through the first half of June; the maximum comes only at the solstice around 21 June.
• ✗ (c) July is often the hottest month because of the lag in heating, but day length is already decreasing by then.

Remember · Summer solstice ~21 June: Sun overhead at the Tropic of Cancer, longest day in the Northern Hemisphere; winter solstice ~22 December: shortest day.

📘 Read it in NCERT: Class 7 Curiosity, Ch 12 (practise this chapter)

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) Neither 1 nor 2

Both statements swap the roles of the two cloud types. It is low, thick clouds that mainly bounce sunlight back and cool the surface, while high, thin clouds let sunlight through but hold back part of the Earth's outgoing heat and so warm the surface.

• ✗ 1. Reflection of sunlight (the cooling effect) is the main job of low, thick clouds. High, thin clouds such as cirrus mostly transmit incoming solar radiation.
• ✗ 2. The warming effect comes from high, thin clouds, which trap some of the infrared radiation leaving the Earth and send it back down. Low clouds are dominated by the cooling effect.

Remember · Low, thick clouds cool the surface (they reflect sunlight); high, thin clouds warm it (they trap outgoing infrared). Deep convective clouds are roughly neutral.

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error