निम्नलिखित युग्मों पर विचार कीजिए : 1. सेफीड — अंतरिक्ष में धूल और गैस के विशाल बादल 2. नीहारिकाएँ — तारे जो आवर्ती रूप से जलते-बुझते हैं 3. पल्सर — न्यूट्रॉन तारे जो तब बनते हैं जब विशाल तारों का ईंधन खत्म हो जाता है और उनका निपात हो जाता है उपर्युक्त युग्मों में से कितने सही सुमेलित हैं?

(d) कोई भी नहीं

निम्नलिखित कथनों पर विचार कीजिए : कथन–I. उष्णकटिबंधीय वर्षावनों की मृदा पोषक तत्त्वों से भरपूर होती है। कथन–II. उष्णकटिबंधीय वर्षावनों के उच्च ताप और आर्द्रता के कारण मृदा में विद्यमान मृत जैव पदार्थ का द्रुत अपघटन होता है। उपर्युक्त कथनों के बारे में, निम्नलिखित में से कौन-सा एक सही है?

(a) कथन–I और कथन–II दोनों सही हैं तथा कथन–II, कथन–I की सही व्याख्या है

(b) कथन–I और कथन–II दोनों सही हैं तथा कथन–II, कथन–I की सही व्याख्या नहीं है

(c) कथन–I सही है किन्तु कथन–II गलत है

निम्नलिखित कथनों पर विचार कीजिए : 1. भूकम्प-लेखी (सीस्मोग्राफ) में S तरंगों से पूर्व P तरंगें अभिलिखित की जाती हैं। 2. P तरंगों में, अलग-अलग कण तरंग प्रसार की दिशा में आगे-पीछे कंपन करते हैं, जबकि S तरंगों में कण तरंग प्रसार की दिशा के समकोणीय ऊपर-नीचे कंपन करते हैं। उपर्युक्त कथनों में से कौन-सा/से सही है/हैं?

(d) न तो 1 और न ही 2

प्रश्न यूपीएससी के हिंदी प्रश्नपत्र से · व्याख्या अभी अंग्रेज़ी में

English हिंदी

Geography

Prelims · Geography · 19 questions

Earth, landforms & geomorphology

Every UPSC Prelims question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

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UPSC syllabus: “Indian and World Geography-Physical, Social, Economic Geography of India and the World.” Sub-topics in the detailed syllabus →

Prelims 2023 · Q5

X-Ray · Core #51 Medium

निम्नलिखित में से कौन-सा एक, समुद्र स्तर में पुनरावर्ती गिरावट का सर्वोत्तम उदाहरण है, जिससे वर्तमान समय की सुविस्तृत कच्छभूमि उत्पन्न हुई है?

Read this question in English

Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?

(a) Bhitarkanika Mangroves · (b) Marakkanam Salt Pans · (c) Naupada Swamp · (d) Rann of Kutch

उत्तर और व्याख्या · explanation in English

Answer: (d) कच्छ का रण

The Rann of Kachchh was once a shallow part of the Arabian Sea. A geological shift closed off its connection with the sea, leaving a vast seasonal marshy salt desert that fills with water in the monsoon and dries into a white salt flat in summer.

✓ (d) The Rann was a shallow part of the Arabian Sea until a geological shift closed its connection with the sea; it is now a huge seasonal marshy salt desert in Gujarat, made up of the Great Rann and the Little Rann.
✗ (a) Bhitarkanika in Odisha is a mangrove forest. NCERT notes that mangroves grow along coasts in salt marshes, tidal creeks, mud flats and estuaries, so it is a coastal tidal wetland, not marshland left behind by a retreating sea.
✗ (b) Marakkanam in Tamil Nadu is known for its coastal salt pans, where salt is made from seawater; these are small human-made works, not a vast natural marshland.

Remember · Rann of Kutch: former shallow part of the Arabian Sea, cut off by a geological shift; now a seasonal marshy salt desert (Great Rann and Little Rann) in Gujarat.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 5 (practise this chapter)

Sources

Encyclopaedia Britannica: Rann of Kachchh ↗ · reference work “The Rann was a once a shallow part of the Arabian Sea , until a geological shift closed off the connection with the sea. The region became a seasonal marshy salt desert over the years. … During the monsoons, the area fills with water, creating a wetland. In the summer, the water evaporates, leaving a white, salty land.”
NCERT Class 11 · India: Physical Environment, Chapter 5 “Mangroves grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2023 · Q56

Medium

निम्नलिखित युग्मों पर विचार कीजिए :

	अंतरिक्ष में पिंड	वर्णन
1.	सेफीड	अंतरिक्ष में धूल और गैस के विशाल बादल
2.	नीहारिकाएँ	तारे जो आवर्ती रूप से जलते-बुझते हैं
3.	पल्सर	न्यूट्रॉन तारे जो तब बनते हैं जब विशाल तारों का ईंधन खत्म हो जाता है और उनका निपात हो जाता है

उपर्युक्त युग्मों में से कितने सही सुमेलित हैं?

Read this question in English

Consider the following pairs:

1. Cepheids — Giant clouds of dust and gas in space

2. Nebulae — Stars which brighten and dim periodically

3. Pulsars — Neutron stars that are formed when massive stars run out of fuel and collapse

How many of the above pairs are correctly matched?

(a) Only one · (b) Only two · (c) All three · (d) None

उत्तर और व्याख्या · explanation in English

Answer: (a) केवल एक

Only pair 3 is correctly matched. Pairs 1 and 2 have their descriptions swapped: Cepheids are stars whose brightness varies in a regular cycle, and nebulae are giant clouds of gas and dust. Pulsars are indeed neutron stars left when a massive star runs out of fuel and collapses.

✗ 1. Cepheids are pulsating variable stars, not clouds. Their regular changes in brightness are used to measure distances to galaxies.
✗ 2. A nebula is a very large cloud of gas (and dust), the place where stars form. It is not a star that brightens and dims.
✓ 3. A neutron star forms when a massive star runs out of fuel and its core collapses. Pulsars are neutron stars that spin fast and sweep a beam of radiation across space.

Remember · Cepheids are stars that brighten and dim in a regular cycle; nebulae are clouds of gas and dust; pulsars are spinning neutron stars.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 2 (practise this chapter)

Sources

NCERT Class 11 · Fundamentals of Physical Geography, Chapter 2 “A galaxy starts to form by accumulation of hydrogen gas in the form of a very large cloud called nebula.”
Cepheid Variables: Brightness Over Time (NASA Science, Hubble) ↗ “shows a class of pulsating star called a Cepheid Variable. Though rare, these stars are reliable distance indicators to galaxies.”
Neutron Stars (NASA Imagine the Universe) ↗ “Neutron stars are formed when a massive star runs out of fuel and collapses. The very central region of the star – the core – collapses, crushing together every proton and electron into a neutron.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q63

Easy

निम्नलिखित कथनों पर विचार कीजिए :

कथन–I: उष्णकटिबंधीय वर्षावनों की मृदा पोषक तत्त्वों से भरपूर होती है।
कथन–II: उष्णकटिबंधीय वर्षावनों के उच्च ताप और आर्द्रता के कारण मृदा में विद्यमान मृत जैव पदार्थ का द्रुत अपघटन होता है।

उपर्युक्त कथनों के बारे में, निम्नलिखित में से कौन-सा एक सही है?

Read this question in English

Consider the following statements:

Statement-I. The soil in tropical rain forests is rich in nutrients.

Statement-II. The high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly.

Which one of the following is correct in respect of the above statements?

(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I · (b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I · (c) Statement-I is correct but Statement-II is incorrect · (d) Statement-I is incorrect but Statement-II is correct

उत्तर और व्याख्या · explanation in English

Answer: (d) कथन–I गलत है किन्तु कथन–II सही है

The soil of a tropical rain forest is poor, not rich, in nutrients. Heat and moisture make bacterial action intense, so dead plant matter is oxidised quickly and very little humus builds up in the soil; heavy rain also leaches nutrients out of tropical soils.

✗ Statement-I Fast decay leaves the soil with very low humus content, and heavy rain leaches away nutrients; lateritic soils of heavy-rain tropical areas are generally deficient in plant nutrients.
✓ Statement-II In humid tropical and equatorial climates bacterial growth and action is intense, so dead vegetation is rapidly oxidised. This is the reason the humus content of the soil stays low, not a sign of richness.

Remember · Fast decay plus heavy rain leave tropical rain forest soil low in humus and nutrients; in cold climates decay is slow, so humus and peat accumulate.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 5 (practise this chapter) · Class 10 Contemporary India – II, Ch 1 (practise this chapter)

Sources

NCERT Class 11 · Fundamentals of Physical Geography, Chapter 5 “In humid tropical and equatorial climates, bacterial growth and action is intense and dead vegetation is rapidly oxidised leaving very low humus content in the soil.”
NCERT Class 10 · Contemporary India – II, Chapter 1 “This soil is the result of intense leaching due to heavy rain. Lateritic soils are mostly deep to very deep, acidic (pH<6.0), generally deficient in plant nutrients”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q65

Easy

निम्नलिखित कथनों पर विचार कीजिए :

1.भूकम्प-लेखी (सीस्मोग्राफ) में S तरंगों से पूर्व P तरंगें अभिलिखित की जाती हैं।
2.P तरंगों में, अलग-अलग कण तरंग प्रसार की दिशा में आगे-पीछे कंपन करते हैं, जबकि S तरंगों में कण तरंग प्रसार की दिशा के समकोणीय ऊपर-नीचे कंपन करते हैं।

उपर्युक्त कथनों में से कौन-सा/से सही है/हैं?

Read this question in English

Consider the following statements:

1. In a seismograph, P waves are recorded earlier than S waves.

2. In P waves, the individual particles vibrate to and fro in the direction of wave propagation whereas in S waves, the particles vibrate up and down at right angles to the direction of wave propagation.

Which of the statements given above is/are correct?

(a) 1 only · (b) 2 only · (c) Both 1 and 2 · (d) Neither 1 nor 2

उत्तर और व्याख्या · explanation in English

Answer: (c) 1 और 2 दोनों

Both statements are correct. P-waves travel faster, so a seismograph records them first, and they vibrate along the direction of travel. S-waves arrive later and vibrate at right angles to that direction.

✓ 1. P-waves are the primary waves: they move faster and are the first to reach the surface. S-waves, the secondary waves, arrive after a time lag, so they are recorded later.
✓ 2. P-waves vibrate parallel to the direction of the wave, pushing and squeezing the material to and fro. S-waves vibrate perpendicular to the wave direction in the vertical plane, so they create troughs and crests.

Remember · P-waves: primary, fastest, particles move to and fro along the path, pass through solids, liquids and gases. S-waves: secondary, slower, particles move up and down, only through solids.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 3 (practise this chapter) · Class 11 Fundamentals of Physical Geography, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · Fundamentals of Physical Geography, Chapter 3 “P-waves move faster and are the first to arrive at the surface. These are also called 'primary waves'.”
NCERT Class 11 · Fundamentals of Physical Geography, Chapter 3 “The direction of vibrations of S-waves is perpendicular to the wave direction in the vertical plane. Hence, they create troughs and crests in the material through which they pass.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

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Class 11 Fundamentals of Physical Geography, Chapter 3cited in 2 explanations
Class 11 India: Physical Environment, Chapter 5cited in 1 explanation
Class 11 Fundamentals of Physical Geography, Chapter 2cited in 1 explanation
Class 11 Fundamentals of Physical Geography, Chapter 5cited in 1 explanation
Class 10 Contemporary India – II, Chapter 1cited in 1 explanation

Earth, landforms & geomorphology

Prelims 2023 · Q5

Prelims 2023 · Q56

Prelims 2023 · Q63

Prelims 2023 · Q65

The same topic in Mains

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