World and Physical Geography

431. Which of the following statements in the context of northern hemispher

Which of the following statements in the context of northern hemisphere is/are correct ?

  • 1. Vernal equinox occurs on March 21.
  • 2. Summer solstice occurs on December 22.
  • 3. Autumnal equinox occurs on September 23.
  • 4. Winter solstice occurs on June 21.

Select the correct answer using the code given below :

[amp_mcq option1=”1 only” option2=”1 and 3 only” option3=”2 and 4 only” option4=”1, 2 and 3 only” correct=”option2″]

This question was previously asked in
UPSC NDA-1 – 2016
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The correct option is B.
Let’s evaluate each statement in the context of the Northern Hemisphere:
1. Vernal equinox occurs around March 20 or 21. This is when the sun is directly over the equator, resulting in approximately equal day and night length everywhere on Earth. In the Northern Hemisphere, this marks the start of spring. This statement is correct.
2. Summer solstice occurs around June 20 or 21. This is when the sun is directly over the Tropic of Cancer (23.5° N), resulting in the longest day and shortest night in the Northern Hemisphere. Statement 2 says it occurs on December 22, which is the date for the *Winter* Solstice in the Northern Hemisphere. This statement is incorrect.
3. Autumnal equinox occurs around September 22 or 23. Like the vernal equinox, the sun is directly over the equator, resulting in approximately equal day and night length. In the Northern Hemisphere, this marks the start of autumn. This statement is correct.
4. Winter solstice occurs around December 21 or 22. This is when the sun is directly over the Tropic of Capricorn (23.5° S), resulting in the shortest day and longest night in the Northern Hemisphere. Statement 4 says it occurs on June 21, which is the date for the *Summer* Solstice in the Northern Hemisphere. This statement is incorrect.
Therefore, only statements 1 and 3 are correct.
The dates of equinoxes and solstices can vary slightly each year due to the Earth’s elliptical orbit and the occurrence of leap years. The terms “vernal” and “autumnal” refer to the seasons in the Northern Hemisphere; in the Southern Hemisphere, the seasons are reversed, so the March equinox is the autumnal equinox and the September equinox is the vernal equinox.

432. Which one of the following is not an international boundary line ?

Which one of the following is not an international boundary line ?

[amp_mcq option1=”Dresden Line” option2=”Durand Line” option3=”Maginot Line” option4=”38th Parallel” correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2016
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An international boundary line separates two or more sovereign states.
– Durand Line: Establishes the border between Afghanistan and Pakistan. It is an international boundary.
– Maginot Line: A defensive line of fortifications built by France along its eastern border primarily with Germany. While a military line, it was situated along a major international border and is often discussed in that context.
– 38th Parallel: Serves as the boundary (or armistice line/demarcation line) between North Korea and South Korea. It is a well-recognized international boundary.
– Dresden Line: Dresden is a major city in Germany. There is no recognized international boundary line known as the “Dresden Line”. It might refer to a historical or local feature, but not an international border.
Therefore, the “Dresden Line” is not an international boundary line.
– International boundary: A line separating countries.
– Durand Line: Afghanistan-Pakistan.
– Maginot Line: French defensive line along the German border.
– 38th Parallel: North-South Korea.
– Dresden is a city, not a boundary line.
Other famous boundary lines include the Radcliffe Line (India-Pakistan), McMahon Line (India-China), Oder-Neisse Line (Germany-Poland), and the Mason-Dixon Line (historical boundary in the US). Military defence lines along borders, like the Maginot Line or Siegfried Line, are distinct from officially demarcated political boundaries, but are often discussed in geographical and historical contexts related to international borders.

433. Directions : The following 05 (Five) items consist of two statements,

Directions : The following 05 (Five) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the answers to these items using the code given below :
Code :

  • Both the Statements are individually true and Statement II is the correct explanation of Statement I.
  • Both the Statements are individually true but Statement II is not the correct explanation of Statement I.
  • Statement I is true but Statement II is false.
  • Statement I is false but Statement II is true.

54.
Statement I: Plantation farming has mostly been practised in humid tropics.
Statement II: The soil of humid tropics is highly fertile.

[amp_mcq option1=”Both the Statements are individually true and Statement II is the correct explanation of Statement I.” option2=”Both the Statements are individually true but Statement II is not the correct explanation of Statement I.” option3=”Statement I is true but Statement II is false.” option4=”Statement I is false but Statement II is true.” correct=”option3″]

This question was previously asked in
UPSC NDA-1 – 2016
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The correct answer is C) Statement I is true but Statement II is false.
Statement I is true. Plantation farming, focusing on commercial crops like tea, coffee, rubber, cocoa, etc., is predominantly practiced in humid tropical and subtropical regions because these crops thrive in such climates (warm temperatures, high rainfall).
Statement II is false. The soils of humid tropics are generally *not* highly fertile. Due to high temperatures and heavy rainfall, organic matter decomposes rapidly, and soluble nutrients are heavily leached away through a process called laterization. This often leaves behind soils rich in iron and aluminum oxides (like Oxisols and Ultisols), which are typically low in fertility and require significant fertilization for sustained agriculture, especially for nutrient-demanding plantation crops.
Despite the low inherent soil fertility, tropical regions support dense forests because nutrients are quickly taken up and stored in the living biomass. When these forests are cleared for agriculture, the limited nutrients in the soil are quickly depleted. Plantation farming in these areas often relies on large inputs of fertilizers and careful management practices.

434. Directions : The following 05 (Five) items consist of two statements,

Directions : The following 05 (Five) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the answers to these items using the code given below :
Code :

  • Both the Statements are individually true and Statement II is the correct explanation of Statement I.
  • Both the Statements are individually true but Statement II is not the correct explanation of Statement I.
  • Statement I is true but Statement II is false.
  • Statement I is false but Statement II is true.

53.
Statement I: Volcanic eruption is accompanied by earthquakes.
Statement II: Volcanoes erupt water vapours and dust particles in the atmosphere.

[amp_mcq option1=”Both the Statements are individually true and Statement II is the correct explanation of Statement I.” option2=”Both the Statements are individually true but Statement II is not the correct explanation of Statement I.” option3=”Statement I is true but Statement II is false.” option4=”Statement I is false but Statement II is true.” correct=”option2″]

This question was previously asked in
UPSC NDA-1 – 2016
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The correct answer is B) Both the Statements are individually true but Statement II is not the correct explanation of Statement I.
Statement I is true. Volcanic eruptions are frequently preceded by or accompanied by earthquakes. These are often seismic events directly related to the movement of magma beneath the surface, the fracturing of rocks due to pressure buildup, or the rapid release of pressure during the eruption.
Statement II is also true. Volcanoes erupt various materials including gases (primarily water vapour), ash, dust particles, lava, and rock fragments.
However, Statement II (what volcanoes erupt) does not explain *why* volcanic eruptions are accompanied by earthquakes (Statement I). The earthquakes are caused by processes happening *before* or *during* the eruption related to magma dynamics and rock mechanics, not by the mere expulsion of water vapour and dust.
Volcanic earthquakes are distinct from tectonic earthquakes, although both involve ground shaking. Volcanic earthquakes are typically shallower and more localized around volcanic structures. They can be indicators of impending eruptions.

435. Directions : The following 05 (Five) items consist of two statements,

Directions : The following 05 (Five) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the answers to these items using the code given below :
Code :

  • Both the Statements are individually true and Statement II is the correct explanation of Statement I.
  • Both the Statements are individually true but Statement II is not the correct explanation of Statement I.
  • Statement I is true but Statement II is false.
  • Statement I is false but Statement II is true.

52.
Statement I: There is high salinity in Red Sea.
Statement II: Rate of evaporation is high in Red Sea.

[amp_mcq option1=”Both the Statements are individually true and Statement II is the correct explanation of Statement I.” option2=”Both the Statements are individually true but Statement II is not the correct explanation of Statement I.” option3=”Statement I is true but Statement II is false.” option4=”Statement I is false but Statement II is true.” correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2016
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The correct answer is A) Both the Statements are individually true and Statement II is the correct explanation of Statement I.
Statement I is true. The Red Sea has one of the highest salinities among the world’s seas, typically ranging between 36 to 41 parts per thousand (ppt), significantly higher than the average ocean salinity of around 35 ppt.
Statement II is true. The Red Sea is located in a hot and arid region with high temperatures, low humidity, and strong winds, leading to very high rates of evaporation. It also receives very little freshwater input from rivers or significant rainfall. High evaporation removes pure water, leaving the salts behind, which directly increases the concentration of salt in the remaining water body. Therefore, high evaporation is the primary reason for the high salinity of the Red Sea.
Other factors contributing to the Red Sea’s high salinity include limited exchange of water with the open ocean (Mediterranean Sea and Arabian Sea through narrow straits) and its location over a rift valley system which might involve subsurface brine inputs in some areas, although evaporation is the dominant factor for the overall high salinity.

436. Match List I with List II and select the correct answer using the code

Match List I with List II and select the correct answer using the code given below the Lists :

List I
(Cloud)		List II
(Characteristic)
A. Cirrus1. Rain giving
B. Stratus2. Feathery appearance
C. Nimbus3. Vertically growing
D. Cumulus4. Horizontally spreading

[amp_mcq option1=”A-3, B-1, C-4, D-2″ option2=”A-3, B-4, C-1, D-2″ option3=”A-2, B-4, C-1, D-3″ option4=”A-2, B-1, C-4, D-3″ correct=”option3″]

This question was previously asked in
UPSC NDA-1 – 2015
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Let’s match the cloud types with their characteristics:
A. Cirrus: Cirrus clouds are high-altitude clouds composed of ice crystals. They are thin, wispy, and have a feathery appearance. So, Cirrus matches with Feathery appearance (2).
B. Stratus: Stratus clouds are low-level, flat, and horizontally extended clouds that often cover the sky like a blanket. So, Stratus matches with Horizontally spreading (4).
C. Nimbus: Nimbus is a prefix or suffix indicating a cloud that produces precipitation (rain, snow, etc.). Nimbostratus and Cumulonimbus are examples of rain-giving clouds. So, Nimbus matches with Rain giving (1).
D. Cumulus: Cumulus clouds are puffy, white clouds with flat bases and rounded tops. They often develop vertically. Large, vertically developed cumulus clouds can become cumulonimbus clouds. So, Cumulus matches with Vertically growing (3).
Putting it together: A-2, B-4, C-1, D-3. This matches option C.
Clouds are classified based on their altitude and appearance. Cirrus are high and feathery, Stratus are low and layered, Nimbus indicates rain, and Cumulus are puffy and grow vertically.
The main cloud types are Cirrus (high, wispy), Cumulus (puffy, vertical), Stratus (layered, horizontal), and Nimbus (rain-bearing). Combinations like Cirrocumulus, Cirrostratus, Altocumulus (mid-level puffy), Altostratus (mid-level layered), Cumulonimbus (large vertical rain cloud), and Nimbostratus (low/mid-level rain cloud) also exist.

437. Consider the following diagram : In which one among the following lett

Consider the following diagram :
In which one among the following lettered areas of the diagram would erosion most likely change the shapes of the riverbed ?

[amp_mcq option1=”A” option2=”B” option3=”C” option4=”D” correct=”option3″]

This question was previously asked in
UPSC NDA-1 – 2015
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The diagram shows a meandering river. In a meandering river bend, water flows faster on the outer bank (due to centrifugal force and deeper water) and slower on the inner bank (where sediment is deposited, forming a point bar). Erosion is most active on the outer bank of the bend due to the faster current. Area C is located on the outer bank of the river bend where erosion is dominant, leading to the cutting away of the bank and changing the shape of the riverbed and bend over time. Areas A and D are on the inner bank where deposition occurs. Area B is likely in a straighter section or near the transition, but erosion is most pronounced at the apex of the outer bend, which is represented by C.
Erosion in a meandering river is concentrated on the outer bends where water flows fastest, while deposition occurs on the inner bends where water is slower.
Over time, continuous erosion on the outer bends and deposition on the inner bends cause the meanders to migrate laterally across the floodplain and can eventually lead to the formation of oxbow lakes when a meander neck is cut off.

438. Match List I with List II and select the correct answer using the code

Match List I with List II and select the correct answer using the code given below the Lists :

List I
(Island)		List II
(Location)
A. Continental island1. Mauritius
B. Coral island2. Madagascar
C. Volcanic island3. Andaman and Nicobar islands
D. Mountain island4. Maldives

[amp_mcq option1=”A-2, B-4, C-1, D-3″ option2=”A-2, B-1, C-4, D-3″ option3=”A-3, B-1, C-4, D-2″ option4=”A-3, B-4, C-1, D-2″ correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2015
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Let’s match the types of islands with their examples:
A. Continental island: These are islands that were formerly part of a continent and became detached due to changes in sea level, geological uplift, or separation of landmasses. Madagascar is a classic example of a continental island that broke away from Africa. So, A matches with 2.
B. Coral island: These islands are formed from the accumulation of coral skeletons and associated organic material. Maldives is an archipelago of coral atolls, making it a prime example of a coral island chain. So, B matches with 4.
C. Volcanic island: These islands are formed by volcanic activity, either from underwater volcanoes reaching the surface or continental volcanic activity. Mauritius was formed by volcanic activity. So, C matches with 1.
D. Mountain island: This term can refer to islands that are essentially the peaks of submerged mountain ranges or fold mountains. The Andaman and Nicobar Islands are believed to be the northern extension of the Arakan Yoma mountain range of Myanmar, making them mountain islands. So, D matches with 3.
Putting it together: A-2, B-4, C-1, D-3. This matches option A.
Islands are classified based on their formation process: Continental islands separated from continents, Coral islands built by coral polyps, Volcanic islands formed by volcanoes, and Mountain islands representing submerged mountain peaks.
Other examples: Great Britain is a continental island. Lakshadweep in India is also a coral island group (atoll). Hawaii is a famous example of a volcanic island chain. Indonesia and Japan are archipelagos largely made up of volcanic islands.

439. Which one of the following weather conditions indicates a sudden fall

Which one of the following weather conditions indicates a sudden fall in barometer reading ?

[amp_mcq option1=”Stormy weather” option2=”Calm weather” option3=”Cold and dry weather” option4=”Hot and sunny weather” correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2015
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A barometer measures atmospheric pressure. A sudden fall in barometer reading indicates a rapid decrease in atmospheric pressure. Falling atmospheric pressure is often associated with approaching low-pressure systems. Low-pressure systems are typically accompanied by unstable atmospheric conditions, rising air, cloud formation, precipitation, and often, stormy weather. Conversely, rising pressure indicates stable conditions (usually associated with clear or fair weather), and steady high pressure indicates calm, dry, and often clear weather. A sudden fall specifically points towards a rapidly developing or approaching weather disturbance, which is characteristic of stormy weather.
A sudden drop in atmospheric pressure (barometer reading) indicates unstable weather conditions, often preceding or accompanying storms.
Forecasters use changes in atmospheric pressure to help predict weather changes. A steady fall may indicate rain, while a rapid fall often indicates a strong storm or depression approaching. High pressure generally leads to clear, calm, and stable weather.

440. Match List I with List II and select the correct answer using the code

Match List I with List II and select the correct answer using the code given below the Lists :

List I
(Region)		List II
(Vegetation)
A. Selvas1. Conifers
B. Savannas2. Mosses and Lichens
C. Taiga3. Epiphytes
D. Tundra4. Grasses and trees

Code :

[amp_mcq option1=”4 1 2 3″ option2=”3 2 1 4″ option3=”3 4 1 2″ option4=”4 2 1 3″ correct=”option3″]

This question was previously asked in
UPSC NDA-1 – 2015
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Let’s match the regions with their characteristic vegetation:
A. Selvas: This term is often used for the equatorial rainforests, particularly in the Amazon basin. These forests are dense and rich in biodiversity, including many epiphytic plants that grow on other plants for support. So, Selvas match with Epiphytes (3).
B. Savannas: Savannas are grasslands with scattered trees, found in tropical and subtropical regions with distinct wet and dry seasons. So, Savannas match with Grasses and trees (4).
C. Taiga: Taiga is the boreal forest, a biome characterized by coniferous forests, found in cold climates. So, Taiga match with Conifers (1).
D. Tundra: Tundra is a treeless polar or alpine biome characterized by permafrost, low temperatures, and short growing seasons. Vegetation is typically limited to mosses, lichens, grasses, sedges, and dwarf shrubs. So, Tundra match with Mosses and Lichens (2).
Putting it together: A-3, B-4, C-1, D-2. This matches option C.
Distinct biomes are characterized by specific climate conditions and resulting vegetation types. Selvas (tropical rainforests) feature epiphytes, Savannas are grasslands with scattered trees, Taiga (boreal forests) are dominated by conifers, and Tundra has low vegetation like mosses and lichens.
Selvas is a term specifically associated with the Amazon rainforest. Epiphytes are plants that grow harmlessly on another plant and get moisture and nutrients from the air, rain, or accumulated debris, common in humid tropical forests. Savannas cover large areas of Africa, Australia, and South America. Taiga is the largest terrestrial biome, located south of the Arctic tundra. Tundra is found in high latitudes and high altitudes.
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