World and Physical Geography

41. The volcanic island ‘Barren Island’ is located in

The volcanic island ‘Barren Island’ is located in

Subscribe on YouTube
Chile
India
Italy
Iceland
This question was previously asked in
UPSC CISF-AC-EXE – 2017
Download PDFAttempt Online
The correct answer is B.
Barren Island is an island located in the Andaman Sea.
It is a volcanic island and contains the only confirmed active volcano in India.
It is part of the Union Territory of Andaman and Nicobar Islands, India.
Barren Island is located about 138 km northeast of Port Blair, the capital of the Andaman and Nicobar Islands. The volcano erupted recently in 2017.

Join Our Telegram Channel

42. Longest day/night is experienced during a year in the

Longest day/night is experienced during a year in the

Subscribe on YouTube
Equator
Pole
Tropics of Cancer/Capricorn
Arctic/Antarctic Circle
This question was previously asked in
UPSC CISF-AC-EXE – 2017
Download PDFAttempt Online
The length of day and night varies significantly with latitude due to the tilt of the Earth’s axis relative to its orbital plane. The maximum variation occurs at the poles (North and South Poles). At the poles, during summer, there is continuous daylight for approximately six months (polar day), and during winter, there is continuous darkness for approximately six months (polar night). This represents the absolute extreme in terms of the duration of continuous day or night experienced during a year. The question asks for the location where the “Longest day/night is experienced during a year”, which refers to the maximum possible duration of either daylight or darkness.
– The Earth’s axial tilt causes seasons and variation in day/night length with latitude.
– The variation is minimal at the equator (always around 12 hours day/night).
– The variation increases towards the poles.
– The poles experience the most extreme variations, including prolonged periods of continuous daylight or darkness.
At the Arctic and Antarctic Circles (approx 66.5° latitude), the sun does not set on the summer solstice (24 hours of daylight) and does not rise on the winter solstice (24 hours of darkness). However, this is a 24-hour period, whereas at the poles, the period extends to roughly six months. Thus, the pole experiences the *longest* continuous day or night period.

Join Our Telegram Channel

43. Chinook is

Chinook is

Subscribe on YouTube
A very warm and dry wind on the eastern slopes of the Rockies
A violent and extremely cold wind of the Tundras
An extremely cold wind in central Siberia
A dry and dusty wind off the west coast of Africa blowing from the deserts
This question was previously asked in
UPSC CISF-AC-EXE – 2017
Download PDFAttempt Online
Chinook is a type of foehn wind, which is a warm, dry, downslope wind that occurs on the leeward side (sheltered side) of a mountain range. The Chinook is specifically associated with the eastern slopes of the Rocky Mountains in North America. As moist air rises over the western slopes, it cools, condenses, and releases precipitation. On the eastern slopes, the air descends, warms adiabatically (due to compression), and becomes drier. This warm, dry wind can cause rapid temperature increases.
– Chinook is a warm, dry wind.
– It occurs on the leeward side of mountain ranges, specifically the eastern slopes of the Rockies.
– It is a type of foehn wind.
Foehn winds occur in many parts of the world, such as the Alps (where they are called Foehn), the Andes (Zonda), and others. The Chinook in North America is famous for causing dramatic temperature rises and rapid snowmelt, earning it the nickname “snow eater.”

Join Our Telegram Channel

44. Which one of the following is *not* the characteristic feature of ‘El

Which one of the following is *not* the characteristic feature of ‘El Ni\u00f1o’ phenomenon impacting the Indian monsoon?

Subscribe on YouTube
It replaces the cold Peruvian current
Appearance of cold current in East Pacific region
Results in reduction of planktons
Results in drought or weak monsoon in India
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
El Niño is characterized by the warming of the surface waters in the central and eastern tropical Pacific Ocean. This *replaces* the usual cold Peruvian current, not leads to the appearance of a cold current. Therefore, the statement “Appearance of cold current in East Pacific region” is incorrect.
El Niño is a phenomenon of warm sea surface temperatures in the eastern equatorial Pacific. It is generally associated with weak monsoon in India and reduction in plankton production due to suppressed upwelling of nutrient-rich cold water.
El Niño is part of the El Niño–Southern Oscillation (ENSO) cycle. Its opposite phase, La Niña, is characterized by colder than average sea surface temperatures in the central and eastern tropical Pacific and is generally associated with a stronger monsoon in India.

Join Our Telegram Channel

45. 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 :

Subscribe on YouTube
List-I (Koppen’s type of climate) List-II (Area of occurrence)
A. Amw 1. Coromandel Coast
B. Cwg 2. West Coast of India
C. As 3. West Rajasthan
D. BWhw 4. Ganga Plain
A-3, B-4, C-1, D-2
A-3, B-1, C-4, D-2
A-2, B-4, C-1, D-3
A-2, B-1, C-4, D-3
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
Based on Koppen’s climate classification as applied to India:
A. Amw (Monsoon with short dry season): Characteristic of the West Coast of India, south of Goa. Matches List-II Option 2.
B. Cwg (Monsoon with dry winter): Characteristic of the Ganga Plain and Northern India. Matches List-II Option 4.
C. As (Monsoon with dry summer): Characteristic of the Coromandel Coast, which receives rainfall during the retreating monsoon. Matches List-II Option 1.
D. BWhw (Hot Desert with dry winter): Characteristic of the Thar Desert region. Matches List-II Option 3.
The correct match is A-2, B-4, C-1, D-3.
This question requires knowledge of Koppen’s climate classification types and their typical areas of occurrence in India.
Koppen’s system uses letters to denote climate types based on temperature and precipitation patterns. ‘A’ indicates tropical climates, ‘B’ dry climates, ‘C’ temperate climates. Sub-letters indicate precipitation patterns (‘m’ – monsoon, ‘w’ – dry winter, ‘s’ – dry summer) and temperature (‘h’ – hot).

Join Our Telegram Channel

46. Which of the following is not among the conditions ideal for inversion

Which of the following is not among the conditions ideal for inversion of temperature?

A long winter night
Clear skies
Still air
Low air pressure near the ground surface
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
Low air pressure near the ground surface is not an ideal condition for temperature inversion; rather, it is generally associated with conditions that prevent inversion.
Temperature inversion is a meteorological phenomenon where temperature increases with increasing altitude, contrary to the usual decrease. Conditions ideal for inversion are typically associated with stable atmospheric conditions that prevent vertical mixing:
1. **Long Winter Night:** Allows for maximum radiative cooling of the ground surface.
2. **Clear Skies:** Clouds absorb and re-emit outgoing radiation, reducing surface cooling. Clear skies allow for efficient outgoing terrestrial radiation and cooling of the ground and the air directly above it.
3. **Still Air:** Wind facilitates mixing of air layers, which disrupts the formation of an inversion layer. Calm or still air allows cold, dense air to accumulate near the surface.
4. **Snow Cover:** A snow-covered surface is an excellent radiator and reflector, enhancing cooling.
5. **Topography:** Valleys and low-lying areas can trap cold air, leading to strong inversions.

Join Our Telegram Channel

Low air pressure near the ground surface is generally associated with rising air (cyclonic conditions) which promotes mixing and instability, opposing the conditions needed for inversion. High pressure is typically associated with sinking air and stable conditions, which favour inversions.

Surface temperature inversions often occur on clear, calm nights when the ground cools rapidly through radiation. The air in contact with the ground cools more than the air above it, leading to the inversion. Inversions can trap pollutants near the surface, leading to reduced air quality.

Subscribe on YouTube

47. What is the name given to a tropical cyclone in the Western Pacific?

What is the name given to a tropical cyclone in the Western Pacific?

Join Our Telegram Channel
Cyclone
Hurricane
Typhoon
Willy-Willy
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
In the Western Pacific, a tropical cyclone is called a Typhoon.
Tropical cyclones are given different names depending on the region where they form:
– **Cyclone:** Used in the North Indian Ocean (Bay of Bengal and Arabian Sea) and the South Pacific/Indian Ocean.
– **Hurricane:** Used in the Atlantic Ocean, Northeast Pacific Ocean, and South Pacific east of the International Date Line.
– **Typhoon:** Used in the Northwest Pacific Ocean, west of the International Date Line.
– **Willy-Willy:** An informal term sometimes used for tropical cyclones off the northwest coast of Australia.
Despite the different names, they are all the same meteorological phenomenon: a rotating storm system characterized by a low-pressure center, strong winds, and heavy rainfall, fueled by the heat released when moist air rises and condenses.

Subscribe on YouTube

48. Which of the following relating to the formation of tropical cyclone i

Which of the following relating to the formation of tropical cyclone is/are correct?

Subscribe on YouTube
  • Large sea surface with temperature above 27 °C
  • Presence of Coriolis force
  • Upper convergence over the sea level system

Select the correct answer using the code given below.

1 and 2
1 and 3
2 and 3
3 only
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
The correct conditions for the formation of a tropical cyclone among the given options are large sea surface temperature above 27 °C and the presence of Coriolis force.
Tropical cyclones require several key conditions to form and intensify:
1. **Warm Sea Surface Temperature:** The ocean surface must be at least 26.5-27 °C (80 °F) down to a depth of at least 50 meters. This provides the latent heat and moisture necessary to fuel the storm.
2. **Coriolis Force:** This force is necessary to initiate the rotation of the air mass around a low-pressure center. It is negligible near the equator, which is why tropical cyclones do not typically form within about 5 degrees latitude of the equator.
3. **Pre-existing Low-Pressure System:** A weak low-pressure area or disturbance is needed as a starting point.
4. **Moist Air:** Sufficient moisture in the atmosphere is required to support the convective development.
5. **Low Vertical Wind Shear:** Wind speed and direction should not change significantly with height. High wind shear can disrupt the storm’s structure.
6. **Upper-Level Divergence:** Air must be diverging aloft above the surface low-pressure system. This allows the rising air in the thunderstorm activity to ventilate and supports further upward motion and intensification. The third statement mentions *upper convergence*, which is contrary to the required condition of *upper divergence*.
The formation process involves the release of latent heat when water vapor condenses, which warms the surrounding air, making it less dense and causing it to rise. This rising air reduces pressure at the surface, drawing in more moist air, creating a feedback loop that fuels the storm. The Coriolis force causes the inflowing air to rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Join Our Telegram Channel

49. Which one of the following is not a bottom relief of the Indian Ocean?

Which one of the following is not a bottom relief of the Indian Ocean?

Subscribe on YouTube
Chagos Ridge
Amsterdam-St. Paul Ridge
Somali Basin
Philippine Trench
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
The Philippine Trench is a major feature of the Pacific Ocean floor, not the Indian Ocean.
The Chagos Ridge is a submarine ridge system located in the central Indian Ocean. The Amsterdam-St. Paul Ridge is part of the Southeast Indian Ridge, a divergent plate boundary in the Indian Ocean. The Somali Basin is a significant abyssal plain located in the western Indian Ocean, off the coast of Somalia. The Philippine Trench, also known as the Mindanao Trench, is a trench located in the western North Pacific Ocean, east of the Philippines.
The Indian Ocean floor features various ridges, basins, plateaus, and trenches, including the Ninety East Ridge, the Central Indian Ridge, the Mid-Indian Ridge, the Sunda Trench (Java Trench), and several abyssal plains like the Somali Basin and the Central Indian Basin. Trenches are typically found at convergent plate boundaries where one tectonic plate subducts beneath another.

Join Our Telegram Channel

50. Consider the following statements with respect to ‘tides’: 1. The ti

Consider the following statements with respect to ‘tides’:

Join Our Telegram Channel
  • 1. The tidal bulges on wide continental shelves have greater height.
  • 2. When tides are channeled between islands, they are called tidal currents.

Which of the statements given above is/are correct?

1 only
2 only
Both 1 and 2
Neither 1 nor 2
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Download PDFAttempt Online
Both statements accurately describe phenomena related to tides: tidal bulges are amplified on wide continental shelves, and channeled tidal flows are called tidal currents.
Statement 1 is correct: As a tidal wave moves from the deep ocean onto a wide, shallow continental shelf, the decrease in water depth causes the wave height (and thus the tidal range) to increase due to a phenomenon called shoaling. The wide expanse of the shelf allows the tidal bulge to build up laterally. Statement 2 is correct: Tidal currents are the horizontal movement of water associated with the rise and fall of the tide. When these tidal flows are forced through narrow passages, such as between islands or in channels, their speed and strength increase, hence they are referred to as tidal currents, often becoming quite strong in these constricted areas.
The maximum height of tides is influenced by factors like the shape of the coastline, the depth of the water, and the configuration of bays and estuaries. Tidal currents are a significant force in coastal environments, affecting sedimentation, erosion, and navigation.

Subscribe on YouTube
Page 1Page 2Page 3Page 4Page 5