Questions & explanations
1. Consider the following statements regarding factors affecting distribution of temperature on Earth:
1. The Earth's albedo is higher at the equator than at the poles due to greater cloud cover.
2. The difference in heating between land and water is greater in summer than in winter.
3. The effect of altitude on temperature is more pronounced in the tropics than in the polar regions.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 2 only
- (d) 1, 2 and 3
Answer: (b) 2 and 3 only
Statement 1 is incorrect: Albedo is the fraction of solar radiation reflected. The poles have higher albedo due to ice and snow cover, while the equator has lower albedo because of dense vegetation and dark ocean surfaces. Cloud cover does affect albedo, but it is higher at mid-latitudes, not necessarily at the equator. Statement 2 is correct: Land heats and cools faster than water, so the temperature contrast between land and water is greater in summer (land hot, water relatively cooler) than in winter. Statement 3 is correct: The lapse rate (temperature decrease with altitude) is fairly consistent globally, but the effect is more noticeable in the tropics because the base temperature is higher; a lapse rate of 6.5°C/km in the tropics produces a larger absolute drop from a high base compared to cold polar regions.
2. With reference to ocean currents and their climatic effects, consider the following statements:
1. The Labrador Current is a warm ocean current that moderates the climate of northeastern North America.
2. The Canary Current brings cold water along the west coast of North Africa, contributing to the aridity of the Sahara Desert.
3. The Kuroshio Current influences the climate of Japan, making it warmer and more humid than other regions at similar latitudes.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (b) 2 and 3 only
Statement 1 is incorrect: The Labrador Current is a cold current that flows from the Arctic along the coast of Labrador and Newfoundland, bringing cold water and icebergs; it cools the climate of northeastern North America, not moderates it. Statement 2 is correct: The Canary Current is a cold current flowing south along the west coast of North Africa, cooling coastal temperatures and reducing rainfall, contributing to the aridity of the Sahara and the Namib desert. Statement 3 is correct: The Kuroshio Current is a warm current from the western Pacific that flows along Japan, bringing warm, moist air, making Japan's climate warmer and more humid than other regions at similar latitudes, such as Siberia.
3. Consider the following statements about earthquake vulnerability in the Himalayan region:
1. The region falls in Seismic Zone V, the highest risk zone.
2. The 2015 Nepal earthquake was caused by thrust faulting along the Main Central Thrust.
3. Liquefaction is a major hazard in the Indo-Gangetic plains during earthquakes.
Which of the above is/are correct?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (c) 1 and 3 only
Statement 1: Parts of the Himalayan region fall in Seismic Zone V (highest risk), but not the entire region — Zone V covers the northeastern states, parts of Himachal, Uttarakhand, and Kashmir. As a generalisation for the Himalayan region, this is broadly accepted as correct. Statement 2: The 2015 Nepal earthquake was caused by thrust faulting on the Main Himalayan Thrust (MHT), not the Main Central Thrust (MCT). The MCT is a different fault system. Statement 2 is INCORRECT. Statement 3: Liquefaction in the loose alluvial soils of the Indo-Gangetic plains during earthquakes is a well-documented hazard — CORRECT. Therefore only Statements 1 and 3 are correct, giving answer (c).
4. A coastal city experiences mild, rainy winters and warm, dry summers. This climate is most likely influenced by:
- (a) A warm ocean current and onshore winds in summer
- (b) A cold ocean current and offshore winds in summer
- (c) Proximity to the equator
- (d) High altitude
Answer: (b) A cold ocean current and offshore winds in summer
The description matches a Mediterranean climate (Köppen Cs), which typically occurs on the west coasts of continents around 30-40° latitude. In summer, the subtropical high-pressure system creates offshore winds and stable, dry conditions. A cold ocean current (e.g., the California Current or Humboldt Current) further stabilizes the air and reduces precipitation. In winter, the westerlies bring onshore winds and rainfall. Option (a) would lead to humid summers (like Florida). Option (c) would yield tropical climate with high rainfall year-round. Option (d) would result in cooler temperatures year-round, not dry summers. Hence, (b) is correct.
5. Consider the following statements:
1. Endogenic forces are constructive, while exogenic forces are destructive.
2. Epeirogenic movements can lead to marine transgressions and regressions.
3. Orogenic movements are characterized by horizontal compression.
Which of the statements given above is/are correct?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (b) 2 and 3 only
Statement 1 is false as an absolute: endogenic forces are both constructive (mountain building) and destructive (earthquakes, volcanic explosions), and exogenic forces include both erosion (destructive) and deposition (constructive). Statement 2 is correct — epeirogenic vertical movements cause the land to rise or sink relative to sea level, producing marine transgressions (sea advances over land) and regressions. Statement 3 is correct — orogenic movements involve horizontal compressional forces that fold and thrust-fault crustal rocks. Therefore Statements 2 and 3 are correct, making (b) the right answer, not (d).
6. With reference to ocean currents, consider the following statements:
1. The Gulf Stream is a warm ocean current that influences the climate of Western Europe.
2. The Labrador Current is a cold current that brings icebergs to the North Atlantic shipping lanes.
3. The Humboldt Current is a warm current that flows along the west coast of South America.
Which of the statements given above is/are correct?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (a) 1 and 2 only
Statement 1 is correct: The Gulf Stream, a warm current originating in the Gulf of Mexico, carries warm water towards Europe, moderating its climate. Statement 2 is correct: The Labrador Current is a cold current from the Arctic that flows south along the coast of Labrador, bringing icebergs that are hazardous to shipping. Statement 3 is incorrect: The Humboldt Current (also known as the Peru Current) is a cold current flowing north along the west coast of South America from the Southern Ocean, not a warm current. It is responsible for the aridity of the Atacama Desert. Hence, only statements 1 and 2 are correct.
7. Which of the following correctly matches an ocean current with its effect on the climate of an adjacent region?
- (a) Gulf Stream – mild climate in Western Europe
- (b) Humboldt Current – heavy rainfall on the west coast of South America
- (c) Labrador Current – warming of the eastern coast of the USA
- (d) West Australian Current – cooling of the south-west coast of Africa
Answer: (a) Gulf Stream – mild climate in Western Europe
The Gulf Stream is a warm current that brings warm water to the North Atlantic, moderating the climate of Western Europe (e.g., UK has mild winters compared to similar latitudes in Canada). Option b is false: the Humboldt (Peru) Current is a cold current that cools the west coast of South America, leading to arid conditions and rich fisheries, not heavy rainfall. Option c is false: the Labrador Current is a cold current that cools the eastern coast of Canada and the USA. Option d is false: the West Australian Current is a cold current that cools the south-west coast of Australia, not Africa.
8. Consider the following statements:
1. The Gulf Stream makes Western Europe warmer than similar latitudes in Canada.
2. The Humboldt Current brings cold water along the west coast of South America, causing arid conditions in coastal Peru.
3. The Labrador Current is a warm ocean current.
Which of the above is/are correct?
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer: (b) 1 and 2 only
The Gulf Stream is a warm current that moderates the climate of Western Europe, making it significantly warmer than other regions at similar latitudes (e.g., Labrador in Canada). The Humboldt Current (also called the Peru Current) is a cold current that flows northward along the west coast of South America, cooling the coastal air and reducing precipitation, leading to the hyper-arid conditions of the Atacama Desert. However, the Labrador Current is a cold current flowing from the Arctic along the coast of Labrador and Newfoundland, bringing cold water. Thus, statement 3 is incorrect.
9. Consider the following statements about the Mediterranean climate:
1. It is characterized by dry summers and wet winters.
2. It is typically found on the western coasts of continents between 30° and 40° latitude.
3. The Mediterranean climate is classified as Cs in the Köppen system.
Which of the statements given above is/are correct?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (d) 1, 2 and 3
The Mediterranean climate (Köppen Cs) is characterized by dry summers and wet winters, typically found on the western coasts of continents between 30° and 40° latitude, such as in California, Chile, South Africa, and the Mediterranean Basin itself. Statement 1 is correct because the climate has a distinct summer drought and winter rainfall. Statement 2 is correct as these areas are influenced by the subtropical high in summer and westerlies in winter. Statement 3 is correct as Köppen classifies it as Cs (C = mild temperate, s = dry summer). Thus, all three statements are correct.
10. Which of the following climatic regions is characterized by a dry summer and wet winter under the Köppen classification?
- (a) Mediterranean
- (b) Tropical
- (c) Tundra
- (d) Desert
Answer: (a) Mediterranean
In the Köppen climate classification, the Mediterranean climate (designated Csa/Csb) features a distinct dry summer due to subtropical high-pressure systems and a wet winter influenced by mid-latitude cyclones. This pattern is typical of regions like the Mediterranean Basin, California, and parts of Chile. Tropical climates (Af, Am, Aw) have high rainfall year-round or a distinct wet season. Tundra (ET) is cold and dry with permafrost. Desert (BWh/BWk) has very low precipitation year-round. Thus, only the Mediterranean climate matches the description of dry summer and wet winter.
11. Which of the following is an example of isostatic uplift leading to plateau formation?
- (a) Deccan Plateau
- (b) Tibetan Plateau
- (c) Colorado Plateau
- (d) Chota Nagpur Plateau
Answer: (c) Colorado Plateau
The Colorado Plateau is a classic example of isostatic uplift — it was uplifted by regional crustal processes including mantle dynamics and isostatic compensation, and the Colorado River then incised to form the Grand Canyon. The Tibetan Plateau was elevated primarily by crustal thickening from the India-Eurasia collision (not purely isostatic uplift as the question implies). The Deccan Plateau is a volcanic lava plateau; Chota Nagpur is an erosional remnant. The Colorado Plateau best illustrates isostatic uplift leading to plateau formation and subsequent river incision.
12. Which of the following rivers is known for its unique 'white water' rapids and is a major source of hydroelectric power in South America?
- (a) Nile River
- (b) Amazon River
- (c) Yangtze River
- (d) Paraná River
Answer: (d) Paraná River
The Paraná River is a highly significant source of hydroelectric power in South America, notably hosting the Itaipu Dam, one of the world's largest. While its main course is not primarily known for extensive white water rapids today, historically, its upper reaches and tributaries, particularly where it descends from the Brazilian Highlands, featured significant rapids and waterfalls, such as the immense Guaíra Falls (now submerged). These powerful natural features were key to its hydroelectric development, thus linking both aspects mentioned in the question.