DAY – 6 : Insta 75 Days Revision Plan-2025 : GEOGRAPHY

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• Question 1 of 30 1. Question 1 points Consider the following statements regarding Earth’s geomagnetic reversals: During a geomagnetic reversal, the magnetic north and south poles switch positions. The South Atlantic Anomaly is considered a potential precursor to the next geomagnetic reversal. Which of the statements given above are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2 Correct Solution: C Earth’s magnetic field, generated by the flow of molten iron in the outer core, acts as a protective shield against solar radiation and cosmic particles. One of the most fascinating phenomena associated with this field is geomagnetic reversal – a process that has occurred multiple times throughout Earth’s history. A geomagnetic reversal is a change in Earth’s magnetic field whereby the positions of the magnetic north and south poles swap places. During this process, the Earth’s magnetic field weakens significantly before reestablishing itself with reversed polarity. This is not to be confused with geographic north and south, which are defined by Earth’s axis of rotation and remain unchanged during magnetic reversals. They occur spontaneously and are statistically random, not periodic The duration of a complete reversal can vary from 1,000 to 22,000 years During transitions, the magnetic field weakens but doesn’t completely vanish Multiple poles might form chaotically in different locations during the reversal process Hence statement 1 is correct The South Atlantic Anomaly (SAA) is a large region of reduced magnetic field intensity stretching from Africa to South America. This anomaly has attracted significant scientific attention because: It represents a significant weakening of Earth’s magnetic field, which has lost about 9% of its strength globally over the last 200 years The region is expanding westward and continues to weaken in intensity The anomaly has recently split into two lobes, creating additional challenges for satellite missions Many scientists consider the South Atlantic Anomaly a potential precursor to an upcoming geomagnetic reversal. The presence of reversed flux patches at the core-mantle boundary beneath South America and South Africa, associated with the SAA, resembles patterns that have preceded previous reversals. Hence statement 2 is correct Incorrect Solution: C Earth’s magnetic field, generated by the flow of molten iron in the outer core, acts as a protective shield against solar radiation and cosmic particles. One of the most fascinating phenomena associated with this field is geomagnetic reversal – a process that has occurred multiple times throughout Earth’s history. A geomagnetic reversal is a change in Earth’s magnetic field whereby the positions of the magnetic north and south poles swap places. During this process, the Earth’s magnetic field weakens significantly before reestablishing itself with reversed polarity. This is not to be confused with geographic north and south, which are defined by Earth’s axis of rotation and remain unchanged during magnetic reversals. They occur spontaneously and are statistically random, not periodic The duration of a complete reversal can vary from 1,000 to 22,000 years During transitions, the magnetic field weakens but doesn’t completely vanish Multiple poles might form chaotically in different locations during the reversal process Hence statement 1 is correct The South Atlantic Anomaly (SAA) is a large region of reduced magnetic field intensity stretching from Africa to South America. This anomaly has attracted significant scientific attention because: It represents a significant weakening of Earth’s magnetic field, which has lost about 9% of its strength globally over the last 200 years The region is expanding westward and continues to weaken in intensity The anomaly has recently split into two lobes, creating additional challenges for satellite missions Many scientists consider the South Atlantic Anomaly a potential precursor to an upcoming geomagnetic reversal. The presence of reversed flux patches at the core-mantle boundary beneath South America and South Africa, associated with the SAA, resembles patterns that have preceded previous reversals. Hence statement 2 is correct

#### 1. Question

Consider the following statements regarding Earth’s geomagnetic reversals:

• During a geomagnetic reversal, the magnetic north and south poles switch positions.

• The South Atlantic Anomaly is considered a potential precursor to the next geomagnetic reversal.

Which of the statements given above are correct?

• (a) 1 only

• (b) 2 only

• (c) Both 1 and 2

• (d) Neither 1 nor 2

Solution: C

Earth’s magnetic field, generated by the flow of molten iron in the outer core, acts as a protective shield against solar radiation and cosmic particles. One of the most fascinating phenomena associated with this field is geomagnetic reversal – a process that has occurred multiple times throughout Earth’s history.

A geomagnetic reversal is a change in Earth’s magnetic field whereby the positions of the magnetic north and south poles swap places. During this process, the Earth’s magnetic field weakens significantly before reestablishing itself with reversed polarity. This is not to be confused with geographic north and south, which are defined by Earth’s axis of rotation and remain unchanged during magnetic reversals.

• They occur spontaneously and are statistically random, not periodic

• The duration of a complete reversal can vary from 1,000 to 22,000 years

• During transitions, the magnetic field weakens but doesn’t completely vanish

• Multiple poles might form chaotically in different locations during the reversal process

Hence statement 1 is correct

The South Atlantic Anomaly (SAA) is a large region of reduced magnetic field intensity stretching from Africa to South America. This anomaly has attracted significant scientific attention because:

• It represents a significant weakening of Earth’s magnetic field, which has lost about 9% of its strength globally over the last 200 years

• The region is expanding westward and continues to weaken in intensity

• The anomaly has recently split into two lobes, creating additional challenges for satellite missions

Many scientists consider the South Atlantic Anomaly a potential precursor to an upcoming geomagnetic reversal. The presence of reversed flux patches at the core-mantle boundary beneath South America and South Africa, associated with the SAA, resembles patterns that have preceded previous reversals.

Hence statement 2 is correct

Solution: C

• They occur spontaneously and are statistically random, not periodic

• The duration of a complete reversal can vary from 1,000 to 22,000 years

• During transitions, the magnetic field weakens but doesn’t completely vanish

• Multiple poles might form chaotically in different locations during the reversal process

Hence statement 1 is correct

The South Atlantic Anomaly (SAA) is a large region of reduced magnetic field intensity stretching from Africa to South America. This anomaly has attracted significant scientific attention because:

• It represents a significant weakening of Earth’s magnetic field, which has lost about 9% of its strength globally over the last 200 years

• The region is expanding westward and continues to weaken in intensity

• The anomaly has recently split into two lobes, creating additional challenges for satellite missions

Hence statement 2 is correct

• Question 2 of 30 2. Question 1 points Which of the following underwater features is characterized by steep sides, flat tops, submerged volcanic peaks, and is often found in chains that mark the movement of tectonic plates over hotspots? (a) Atoll (b) Seamount (c) Guyot (d) Archipelagic apron Correct Solution: C The ocean floor can be broadly categorized into major features like continental shelves, continental slopes, abyssal plains, mid-oceanic ridges, and trenches, alongside numerous minor relief features including seamounts, guyots, submarine canyons, and atolls. A guyot, also known as a tablemount, is a flat-topped, submerged volcanic mountain, typically found in the Pacific Ocean, that is more than 200 meters (660 feet) below the surface of the sea Incorrect Solution: C The ocean floor can be broadly categorized into major features like continental shelves, continental slopes, abyssal plains, mid-oceanic ridges, and trenches, alongside numerous minor relief features including seamounts, guyots, submarine canyons, and atolls. A guyot, also known as a tablemount, is a flat-topped, submerged volcanic mountain, typically found in the Pacific Ocean, that is more than 200 meters (660 feet) below the surface of the sea

#### 2. Question

Which of the following underwater features is characterized by steep sides, flat tops, submerged volcanic peaks, and is often found in chains that mark the movement of tectonic plates over hotspots?

• (b) Seamount

• (d) Archipelagic apron

Solution: C

The ocean floor can be broadly categorized into major features like continental shelves, continental slopes, abyssal plains, mid-oceanic ridges, and trenches, alongside numerous minor relief features including seamounts, guyots, submarine canyons, and atolls.

A guyot, also known as a tablemount, is a flat-topped, submerged volcanic mountain, typically found in the Pacific Ocean, that is more than 200 meters (660 feet) below the surface of the sea

Solution: C

A guyot, also known as a tablemount, is a flat-topped, submerged volcanic mountain, typically found in the Pacific Ocean, that is more than 200 meters (660 feet) below the surface of the sea

• Question 3 of 30 3. Question 1 points This type of chemical weathering process is particularly intense in tropical and subtropical regions with high rainfall and temperatures. It involves the leaching of silica and accumulation of aluminium and iron oxides, creating reddish soils. It is commonly associated with laterite formation.” Identify the weathering process: (a) Carbonation (b) Hydrolysis (c) Laterization (d) Oxidation Correct Solution: C The process described—intense chemical weathering in tropical and subtropical regions with high rainfall and temperatures, leading to the leaching of silica and accumulation of aluminium and iron oxides, resulting in reddish soils—is known as laterization. This process is responsible for the formation of laterite soils, which are rich in iron and aluminium oxides. It refers to the intense chemical weathering process in tropical and subtropical regions that leads to the formation of laterite soils, characterized by the leaching of silica and accumulation of iron and aluminium oxides, giving the soil a reddish colour. Incorrect Solution: C The process described—intense chemical weathering in tropical and subtropical regions with high rainfall and temperatures, leading to the leaching of silica and accumulation of aluminium and iron oxides, resulting in reddish soils—is known as laterization. This process is responsible for the formation of laterite soils, which are rich in iron and aluminium oxides. It refers to the intense chemical weathering process in tropical and subtropical regions that leads to the formation of laterite soils, characterized by the leaching of silica and accumulation of iron and aluminium oxides, giving the soil a reddish colour.

#### 3. Question

This type of chemical weathering process is particularly intense in tropical and subtropical regions with high rainfall and temperatures. It involves the leaching of silica and accumulation of aluminium and iron oxides, creating reddish soils. It is commonly associated with laterite formation.” Identify the weathering process:

• (a) Carbonation

• (b) Hydrolysis

• (c) Laterization

• (d) Oxidation

Solution: C

The process described—intense chemical weathering in tropical and subtropical regions with high rainfall and temperatures, leading to the leaching of silica and accumulation of aluminium and iron oxides, resulting in reddish soils—is known as laterization. This process is responsible for the formation of laterite soils, which are rich in iron and aluminium oxides.

It refers to the intense chemical weathering process in tropical and subtropical regions that leads to the formation of laterite soils, characterized by the leaching of silica and accumulation of iron and aluminium oxides, giving the soil a reddish colour.

Solution: C

• Question 4 of 30 4. Question 1 points Consider the following coastal features: Tombolo Fjord Stack Spit Barchan Which of the above are depositional landforms created by wave action and longshore drift? (a) 1 and 4 only (b) 2 and 3 only (c) 1, 3 and 4 only (d) 3, 4 and 5 only Correct Solution: A Tombolo A tombolo is formed when deposited sediments connect an offshore island to the mainland. Tombolo forms through the deposition of sediment that gradually extends from the shore to an offshore island or rock, creating a natural land bridge. Specifically, if a spit moves in the direction of island and connects it to the mainland then it becomes a tombolo. Hence, statement 1 is correct. A fjord is a long, narrow inlet with steep sides or cliffs, formed by a glacier, that is often filled with seawater. Hence, statement 2 is incorrect. A sea stack, is a geological landform consisting of a tall, often vertical column of rock that has been separated from a headland or cliff by coastal erosion, typically through the collapse of an arch. It is erosional landform. Hence, statement 3 is incorrect. Spit When longshore drift travels past a point (e.g. river mouth or re-entrant) where the dominant drift direction and shoreline do not veer in the same direction. The formed through deposition of material at coastlines through the process of longshore drift. Furthermore, spits are largely formed by the deposition of sediments like the sand by the huge water bodies such as the oceans or seas. Hence, statement 4 is correct. A barchan is a crescent-shaped sand dune formed by wind action, with the horns (or wings) of the crescent pointing downwind, and is a common landform in sandy deserts with a single dominant wind direction. Hence, statement 5 is incorrect. Incorrect Solution: A Tombolo A tombolo is formed when deposited sediments connect an offshore island to the mainland. Tombolo forms through the deposition of sediment that gradually extends from the shore to an offshore island or rock, creating a natural land bridge. Specifically, if a spit moves in the direction of island and connects it to the mainland then it becomes a tombolo. Hence, statement 1 is correct. A fjord is a long, narrow inlet with steep sides or cliffs, formed by a glacier, that is often filled with seawater. Hence, statement 2 is incorrect. A sea stack, is a geological landform consisting of a tall, often vertical column of rock that has been separated from a headland or cliff by coastal erosion, typically through the collapse of an arch. It is erosional landform. Hence, statement 3 is incorrect. Spit When longshore drift travels past a point (e.g. river mouth or re-entrant) where the dominant drift direction and shoreline do not veer in the same direction. The formed through deposition of material at coastlines through the process of longshore drift. Furthermore, spits are largely formed by the deposition of sediments like the sand by the huge water bodies such as the oceans or seas. Hence, statement 4 is correct. A barchan is a crescent-shaped sand dune formed by wind action, with the horns (or wings) of the crescent pointing downwind, and is a common landform in sandy deserts with a single dominant wind direction. Hence, statement 5 is incorrect.

#### 4. Question

Consider the following coastal features:

Which of the above are depositional landforms created by wave action and longshore drift?

• (a) 1 and 4 only

• (b) 2 and 3 only

• (c) 1, 3 and 4 only

• (d) 3, 4 and 5 only

Solution: A

Tombolo

• A tombolo is formed when deposited sediments connect an offshore island to the mainland. Tombolo forms through the deposition of sediment that gradually extends from the shore to an offshore island or rock, creating a natural land bridge. Specifically, if a spit moves in the direction of island and connects it to the mainland then it becomes a tombolo.

Hence, statement 1 is correct.

A fjord is a long, narrow inlet with steep sides or cliffs, formed by a glacier, that is often filled with seawater.

Hence, statement 2 is incorrect.

A sea stack, is a geological landform consisting of a tall, often vertical column of rock that has been separated from a headland or cliff by coastal erosion, typically through the collapse of an arch.

It is erosional landform.

Hence, statement 3 is incorrect.

• When longshore drift travels past a point (e.g. river mouth or re-entrant) where the dominant drift direction and shoreline do not veer in the same direction. The formed through deposition of material at coastlines through the process of longshore drift. Furthermore, spits are largely formed by the deposition of sediments like the sand by the huge water bodies such as the oceans or seas.

• Hence, statement 4 is correct.

A barchan is a crescent-shaped sand dune formed by wind action, with the horns (or wings) of the crescent pointing downwind, and is a common landform in sandy deserts with a single dominant wind direction.

Hence, statement 5 is incorrect.

Solution: A

Tombolo

Hence, statement 1 is correct.

A fjord is a long, narrow inlet with steep sides or cliffs, formed by a glacier, that is often filled with seawater.

Hence, statement 2 is incorrect.

It is erosional landform.

Hence, statement 3 is incorrect.

• Hence, statement 4 is correct.

Hence, statement 5 is incorrect.

• Question 5 of 30 5. Question 1 points Consider the following statements with reference to ‘Ekman Transport’: Statement-I: In the Northern Hemisphere, Ekman transport causes surface water to move at approximately 90 degrees to the right of the wind direction. Statement-II: The Coriolis effect diminishes with depth, causing each successive layer of water to move at a different angle and speed than the layer above. 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 Correct Solution: C Ekman Transport is a fundamental oceanographic phenomenon that explains how wind-driven surface currents interact with the Earth’s rotation to create a complex pattern of water movement in the ocean. Named after Swedish oceanographer Vagn Walfrid Ekman who first described this phenomenon in 1902, it has significant implications for ocean circulation, nutrient distribution, and climate patterns. When wind blows over the ocean surface, the resulting water movement is affected by the Coriolis effect (Earth’s rotation). The depth-averaged net water transport in the Ekman layer is perpendicular (90°) to the wind direction. The Coriolis effect plus the frictional coupling of wind and water (Ekman transport) cause net movement of surface water at about 90 degrees to the right of the wind direction in the Northern Hemisphere and to the left of the wind direction in the Southern Hemisphere. Hence statement 1 is correct The Coriolis effect does not diminish with depth – it is a constant force at any particular latitude. What changes with depth is the speed and direction of water movement, but this is not because the Coriolis effect weakens. Rather, it’s because each layer of water is moved by friction from the layer above it, and this frictional force decreases with depth. Hence statement 2 is incorrect Incorrect Solution: C Ekman Transport is a fundamental oceanographic phenomenon that explains how wind-driven surface currents interact with the Earth’s rotation to create a complex pattern of water movement in the ocean. Named after Swedish oceanographer Vagn Walfrid Ekman who first described this phenomenon in 1902, it has significant implications for ocean circulation, nutrient distribution, and climate patterns. When wind blows over the ocean surface, the resulting water movement is affected by the Coriolis effect (Earth’s rotation). The depth-averaged net water transport in the Ekman layer is perpendicular (90°) to the wind direction. The Coriolis effect plus the frictional coupling of wind and water (Ekman transport) cause net movement of surface water at about 90 degrees to the right of the wind direction in the Northern Hemisphere and to the left of the wind direction in the Southern Hemisphere. Hence statement 1 is correct The Coriolis effect does not diminish with depth – it is a constant force at any particular latitude. What changes with depth is the speed and direction of water movement, but this is not because the Coriolis effect weakens. Rather, it’s because each layer of water is moved by friction from the layer above it, and this frictional force decreases with depth. Hence statement 2 is incorrect

#### 5. Question

Consider the following statements with reference to ‘Ekman Transport’: Statement-I: In the Northern Hemisphere, Ekman transport causes surface water to move at approximately 90 degrees to the right of the wind direction. Statement-II: The Coriolis effect diminishes with depth, causing each successive layer of water to move at a different angle and speed than the layer above.

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

Solution: C

Ekman Transport is a fundamental oceanographic phenomenon that explains how wind-driven surface currents interact with the Earth’s rotation to create a complex pattern of water movement in the ocean. Named after Swedish oceanographer Vagn Walfrid Ekman who first described this phenomenon in 1902, it has significant implications for ocean circulation, nutrient distribution, and climate patterns.

When wind blows over the ocean surface, the resulting water movement is affected by the Coriolis effect (Earth’s rotation). The depth-averaged net water transport in the Ekman layer is perpendicular (90°) to the wind direction.

The Coriolis effect plus the frictional coupling of wind and water (Ekman transport) cause net movement of surface water at about 90 degrees to the right of the wind direction in the Northern Hemisphere and to the left of the wind direction in the Southern Hemisphere.

Hence statement 1 is correct

The Coriolis effect does not diminish with depth – it is a constant force at any particular latitude. What changes with depth is the speed and direction of water movement, but this is not because the Coriolis effect weakens. Rather, it’s because each layer of water is moved by friction from the layer above it, and this frictional force decreases with depth.

Hence statement 2 is incorrect

Solution: C

Hence statement 1 is correct

Hence statement 2 is incorrect

• Question 6 of 30 6. Question 1 points In the context of the Solar System, consider the following statements: The Kuiper Belt is primarily located between the orbits of Neptune and Pluto. Gas giants are primarily composed of helium and hydrogen with small solid cores. Discovery of Eris was one of the reasons for Pluto’s reclassification as a dwarf planet. How many of the statements given above are correct? a) Only one b) Only two c) All three d) None Correct Solution: B The Solar System is a complex arrangement of celestial bodies that formed approximately 4.6 billion years ago from a massive cloud of gas and dust. It consists of the Sun at its center, eight planets, dwarf planets, moons, asteroids, comets, and other objects. The inner edge of the doughnut-shaped Kuiper Belt begins at the orbit of Neptune and a distance of around 2.8 billion miles (4.8 billion kilometers) from the sun, with its main concentration of bodies ending at around 4.6 billion miles (7.4 billion km) from the star. Additionally, Pluto is described as a dwarf planet in the Kuiper bel”, indicating that Pluto is located within the Kuiper Belt, not at its outer boundary. The Kuiper Belt extends beyond Pluto and contains many other objects. Hence statement 1 is incorrect A gas giant is a giant planet composed mainly of hydrogen and helium. Jupiter and Saturn are the gas giants of the Solar System. They are thought to consist of an outer layer of compressed molecular hydrogen surrounding a layer of liquid metallic hydrogen, with probably a molten rocky core inside. Hence statement 2 is correct In 2005, astronomers discovered Eris, a celestial body in the Kuiper Belt, which was initially thought to be larger than Pluto. The discovery of Eris, along with the prospect of other similar objects, created a dilemma for astronomers: if Pluto was considered a planet, should Eris and other similar objects also be classified as planets? To avoid confusion and potentially increasing the number of planets, the IAU revised its definition of a planet in 2006, leading to Pluto’s reclassification as a dwarf planet. While initially thought to be larger than Pluto, later observations showed that Eris is slightly smaller than Pluto, but more massive. Eris, along with Pluto and Ceres, was classified as a dwarf planet under the new criteria. The IAU’s definition of a planet requires an object to: 1) orbit the sun, 2) have sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, and 3) have cleared its neighbouring region of other objects. Pluto, while meeting the first two criteria, fails the third because it shares its orbital neighbourhood with other objects. Hence statement 3 is correct Incorrect Solution: B The Solar System is a complex arrangement of celestial bodies that formed approximately 4.6 billion years ago from a massive cloud of gas and dust. It consists of the Sun at its center, eight planets, dwarf planets, moons, asteroids, comets, and other objects. The inner edge of the doughnut-shaped Kuiper Belt begins at the orbit of Neptune and a distance of around 2.8 billion miles (4.8 billion kilometers) from the sun, with its main concentration of bodies ending at around 4.6 billion miles (7.4 billion km) from the star. Additionally, Pluto is described as a dwarf planet in the Kuiper bel”, indicating that Pluto is located within the Kuiper Belt, not at its outer boundary. The Kuiper Belt extends beyond Pluto and contains many other objects. Hence statement 1 is incorrect A gas giant is a giant planet composed mainly of hydrogen and helium. Jupiter and Saturn are the gas giants of the Solar System. They are thought to consist of an outer layer of compressed molecular hydrogen surrounding a layer of liquid metallic hydrogen, with probably a molten rocky core inside. Hence statement 2 is correct In 2005, astronomers discovered Eris, a celestial body in the Kuiper Belt, which was initially thought to be larger than Pluto. The discovery of Eris, along with the prospect of other similar objects, created a dilemma for astronomers: if Pluto was considered a planet, should Eris and other similar objects also be classified as planets? To avoid confusion and potentially increasing the number of planets, the IAU revised its definition of a planet in 2006, leading to Pluto’s reclassification as a dwarf planet. While initially thought to be larger than Pluto, later observations showed that Eris is slightly smaller than Pluto, but more massive. Eris, along with Pluto and Ceres, was classified as a dwarf planet under the new criteria. The IAU’s definition of a planet requires an object to: 1) orbit the sun, 2) have sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, and 3) have cleared its neighbouring region of other objects. Pluto, while meeting the first two criteria, fails the third because it shares its orbital neighbourhood with other objects. Hence statement 3 is correct

#### 6. Question

In the context of the Solar System, consider the following statements:

• The Kuiper Belt is primarily located between the orbits of Neptune and Pluto.

• Gas giants are primarily composed of helium and hydrogen with small solid cores.

• Discovery of Eris was one of the reasons for Pluto’s reclassification as a dwarf planet.

How many of the statements given above are correct?

• a) Only one

• b) Only two

• c) All three

Solution: B

The Solar System is a complex arrangement of celestial bodies that formed approximately 4.6 billion years ago from a massive cloud of gas and dust. It consists of the Sun at its center, eight planets, dwarf planets, moons, asteroids, comets, and other objects.

The inner edge of the doughnut-shaped Kuiper Belt begins at the orbit of Neptune and a distance of around 2.8 billion miles (4.8 billion kilometers) from the sun, with its main concentration of bodies ending at around 4.6 billion miles (7.4 billion km) from the star. Additionally, Pluto is described as a dwarf planet in the Kuiper bel”, indicating that Pluto is located within the Kuiper Belt, not at its outer boundary. The Kuiper Belt extends beyond Pluto and contains many other objects.

Hence statement 1 is incorrect

A gas giant is a giant planet composed mainly of hydrogen and helium. Jupiter and Saturn are the gas giants of the Solar System. They are thought to consist of an outer layer of compressed molecular hydrogen surrounding a layer of liquid metallic hydrogen, with probably a molten rocky core inside.

Hence statement 2 is correct

In 2005, astronomers discovered Eris, a celestial body in the Kuiper Belt, which was initially thought to be larger than Pluto. The discovery of Eris, along with the prospect of other similar objects, created a dilemma for astronomers: if Pluto was considered a planet, should Eris and other similar objects also be classified as planets?

To avoid confusion and potentially increasing the number of planets, the IAU revised its definition of a planet in 2006, leading to Pluto’s reclassification as a dwarf planet. While initially thought to be larger than Pluto, later observations showed that Eris is slightly smaller than Pluto, but more massive.

Eris, along with Pluto and Ceres, was classified as a dwarf planet under the new criteria.

The IAU’s definition of a planet requires an object to: 1) orbit the sun, 2) have sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, and 3) have cleared its neighbouring region of other objects. Pluto, while meeting the first two criteria, fails the third because it shares its orbital neighbourhood with other objects.

Hence statement 3 is correct

Solution: B

Hence statement 1 is incorrect

Hence statement 2 is correct

Eris, along with Pluto and Ceres, was classified as a dwarf planet under the new criteria.

Hence statement 3 is correct

• Question 7 of 30 7. Question 1 points Consider the following statements: Statement I: The low velocity zone in the upper mantle corresponds to the asthenosphere, which enables isostatic adjustment and plate tectonic movements. Statement II: The increased seismic velocity in the asthenosphere is often attributed to its long distance to melting temperatures. 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, but 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. Correct Solution: C The asthenosphere is a crucial layer within Earth’s upper mantle, located beneath the rigid lithosphere. It is characterized by reduced seismic wave velocities, earning it the name low velocity zone (LVZ). This layer plays a pivotal role in facilitating plate tectonics and isostatic adjustments. The asthenosphere’s weak, ductile nature allows it to act as a lubricating layer, enabling the lithospheric plates to move. Studies confirm that a thin, fluid asthenosphere accelerates isostatic adjustments (e.g., rapid post-glacial rebound in Fennoscandia and Canada). Plate tectonics is facilitated by the asthenosphere’s low viscosity, which decouples the lithosphere from the deeper mantle Hence statement 1 is correct The asthenosphere is a region of the upper mantle characterized by lower seismic velocities compared to the overlying lithosphere. Seismic waves, which are used to study the Earth’s interior, travel slower through the asthenosphere. The asthenosphere is thought to be a region where the mantle rock is close to its melting point, and a small amount of partial melting may occur. The presence of even a small amount of melt can significantly reduce the seismic velocity because seismic waves travel slower through a liquid or partially molten material than through a solid. While partial melting is a key factor, other factors like temperature, water content, and the anelastic properties of the rocks in the asthenosphere also play a role in determining seismic velocity. Some models suggest that partial melting, or even the presence of water, can cause anelastic relaxation along grain boundaries, further reducing seismic velocities. The decreased seismic velocity in the asthenosphere is often attributed to its proximity to melting temperatures, which can lead to partial melting and a reduction in rigidity, although the exact mechanism and extent of melt are still debated. Hence statement 2 is incorrect Incorrect Solution: C The asthenosphere is a crucial layer within Earth’s upper mantle, located beneath the rigid lithosphere. It is characterized by reduced seismic wave velocities, earning it the name low velocity zone (LVZ). This layer plays a pivotal role in facilitating plate tectonics and isostatic adjustments. The asthenosphere’s weak, ductile nature allows it to act as a lubricating layer, enabling the lithospheric plates to move. Studies confirm that a thin, fluid asthenosphere accelerates isostatic adjustments (e.g., rapid post-glacial rebound in Fennoscandia and Canada). Plate tectonics is facilitated by the asthenosphere’s low viscosity, which decouples the lithosphere from the deeper mantle Hence statement 1 is correct The asthenosphere is a region of the upper mantle characterized by lower seismic velocities compared to the overlying lithosphere. Seismic waves, which are used to study the Earth’s interior, travel slower through the asthenosphere. The asthenosphere is thought to be a region where the mantle rock is close to its melting point, and a small amount of partial melting may occur. The presence of even a small amount of melt can significantly reduce the seismic velocity because seismic waves travel slower through a liquid or partially molten material than through a solid. While partial melting is a key factor, other factors like temperature, water content, and the anelastic properties of the rocks in the asthenosphere also play a role in determining seismic velocity. Some models suggest that partial melting, or even the presence of water, can cause anelastic relaxation along grain boundaries, further reducing seismic velocities. The decreased seismic velocity in the asthenosphere is often attributed to its proximity to melting temperatures, which can lead to partial melting and a reduction in rigidity, although the exact mechanism and extent of melt are still debated. Hence statement 2 is incorrect

#### 7. Question

Consider the following statements:

Statement I: The low velocity zone in the upper mantle corresponds to the asthenosphere, which enables isostatic adjustment and plate tectonic movements.

Statement II: The increased seismic velocity in the asthenosphere is often attributed to its long distance to melting temperatures.

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, but 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.

Solution: C

The asthenosphere is a crucial layer within Earth’s upper mantle, located beneath the rigid lithosphere. It is characterized by reduced seismic wave velocities, earning it the name low velocity zone (LVZ). This layer plays a pivotal role in facilitating plate tectonics and isostatic adjustments.

• The asthenosphere’s weak, ductile nature allows it to act as a lubricating layer, enabling the lithospheric plates to move. Studies confirm that a thin, fluid asthenosphere accelerates isostatic adjustments (e.g., rapid post-glacial rebound in Fennoscandia and Canada).

• Plate tectonics is facilitated by the asthenosphere’s low viscosity, which decouples the lithosphere from the deeper mantle

Hence statement 1 is correct

The asthenosphere is a region of the upper mantle characterized by lower seismic velocities compared to the overlying lithosphere. Seismic waves, which are used to study the Earth’s interior, travel slower through the asthenosphere. The asthenosphere is thought to be a region where the mantle rock is close to its melting point, and a small amount of partial melting may occur.

The presence of even a small amount of melt can significantly reduce the seismic velocity because seismic waves travel slower through a liquid or partially molten material than through a solid.

While partial melting is a key factor, other factors like temperature, water content, and the anelastic properties of the rocks in the asthenosphere also play a role in determining seismic velocity.

Some models suggest that partial melting, or even the presence of water, can cause anelastic relaxation along grain boundaries, further reducing seismic velocities.

The decreased seismic velocity in the asthenosphere is often attributed to its proximity to melting temperatures, which can lead to partial melting and a reduction in rigidity, although the exact mechanism and extent of melt are still debated.

Hence statement 2 is incorrect

Solution: C

• Plate tectonics is facilitated by the asthenosphere’s low viscosity, which decouples the lithosphere from the deeper mantle

Hence statement 1 is correct

The presence of even a small amount of melt can significantly reduce the seismic velocity because seismic waves travel slower through a liquid or partially molten material than through a solid.

While partial melting is a key factor, other factors like temperature, water content, and the anelastic properties of the rocks in the asthenosphere also play a role in determining seismic velocity.

Some models suggest that partial melting, or even the presence of water, can cause anelastic relaxation along grain boundaries, further reducing seismic velocities.

Hence statement 2 is incorrect

• Question 8 of 30 8. Question 1 points With reference to earthquake monitoring, consider the following statements: The Mercalli intensity scale measures the observed effects of an earthquake, while the Richter scale measures the energy released. Earthquake early warning systems utilize the time difference between P-waves and S-waves to provide alerts. Deep-focus earthquakes generally produce less surface damage than shallow-focus earthquakes of similar magnitude. How many of the above statements are correct? a) Only one b) Only two c) All three d) None Correct Solution: C Earthquakes are among the most powerful and destructive natural phenomena on Earth. Monitoring these seismic events requires sophisticated techniques to measure their magnitude, intensity, and potential impact. The Mercalli and Richter scales are both used when measuring the impacts of seismic activity. However, while the Richter scale measures the magnitude of the earthquake (meaning the force of the earthquake), the Mercalli scale measures the physical impact of the earthquake within a given location. Hence statement 1 is correct Earthquakes generate different types of seismic waves, including P-waves (primary waves) and S-waves (secondary waves). P-waves travel faster through the Earth’s crust than S-waves. Earthquake early warning systems (EEWS) detect the initial P-waves and, based on their travel time and location, estimate the time of arrival of the more destructive S-waves and surface waves. EEWS then issue alerts before the arrival of the damaging S-waves, allowing people and systems to take protective actions. The time difference between the arrival of P-waves and S-waves at a seismic station can indicate how far the station is from the source of the earthquake. EEWS can provide crucial seconds to minutes of warning time, enabling actions like shutting down industrial operations, reducing train speeds, and evacuating buildings. Hence statement 2 is correct Thee shallower an earthquake, the more damage it can produce at the surface; intermediate and deep-focus earthquakes are rarely destructive. The deep focus earthquakes are less damaging because. the crust in motion is very close to the surface and its effect passes away quickly. they can be predicted well in advance and precautions can be taken. they are very rare and their intensity is usually low to moderate. Hence statement 3 is correct Incorrect Solution: C Earthquakes are among the most powerful and destructive natural phenomena on Earth. Monitoring these seismic events requires sophisticated techniques to measure their magnitude, intensity, and potential impact. The Mercalli and Richter scales are both used when measuring the impacts of seismic activity. However, while the Richter scale measures the magnitude of the earthquake (meaning the force of the earthquake), the Mercalli scale measures the physical impact of the earthquake within a given location. Hence statement 1 is correct Earthquakes generate different types of seismic waves, including P-waves (primary waves) and S-waves (secondary waves). P-waves travel faster through the Earth’s crust than S-waves. Earthquake early warning systems (EEWS) detect the initial P-waves and, based on their travel time and location, estimate the time of arrival of the more destructive S-waves and surface waves. EEWS then issue alerts before the arrival of the damaging S-waves, allowing people and systems to take protective actions. The time difference between the arrival of P-waves and S-waves at a seismic station can indicate how far the station is from the source of the earthquake. EEWS can provide crucial seconds to minutes of warning time, enabling actions like shutting down industrial operations, reducing train speeds, and evacuating buildings. Hence statement 2 is correct Thee shallower an earthquake, the more damage it can produce at the surface; intermediate and deep-focus earthquakes are rarely destructive. The deep focus earthquakes are less damaging because. the crust in motion is very close to the surface and its effect passes away quickly. they can be predicted well in advance and precautions can be taken. they are very rare and their intensity is usually low to moderate. Hence statement 3 is correct

#### 8. Question

With reference to earthquake monitoring, consider the following statements:

• The Mercalli intensity scale measures the observed effects of an earthquake, while the Richter scale measures the energy released.

• Earthquake early warning systems utilize the time difference between P-waves and S-waves to provide alerts.

• Deep-focus earthquakes generally produce less surface damage than shallow-focus earthquakes of similar magnitude.

How many of the above statements are correct?

• a) Only one

• b) Only two

• c) All three

Solution: C

Earthquakes are among the most powerful and destructive natural phenomena on Earth. Monitoring these seismic events requires sophisticated techniques to measure their magnitude, intensity, and potential impact.

The Mercalli and Richter scales are both used when measuring the impacts of seismic activity. However, while the Richter scale measures the magnitude of the earthquake (meaning the force of the earthquake), the Mercalli scale measures the physical impact of the earthquake within a given location.

Hence statement 1 is correct

Earthquakes generate different types of seismic waves, including P-waves (primary waves) and S-waves (secondary waves). P-waves travel faster through the Earth’s crust than S-waves. Earthquake early warning systems (EEWS) detect the initial P-waves and, based on their travel time and location, estimate the time of arrival of the more destructive S-waves and surface waves. EEWS then issue alerts before the arrival of the damaging S-waves, allowing people and systems to take protective actions.

The time difference between the arrival of P-waves and S-waves at a seismic station can indicate how far the station is from the source of the earthquake. EEWS can provide crucial seconds to minutes of warning time, enabling actions like shutting down industrial operations, reducing train speeds, and evacuating buildings.

Hence statement 2 is correct

Thee shallower an earthquake, the more damage it can produce at the surface; intermediate and deep-focus earthquakes are rarely destructive. The deep focus earthquakes are less damaging because. the crust in motion is very close to the surface and its effect passes away quickly. they can be predicted well in advance and precautions can be taken. they are very rare and their intensity is usually low to moderate.

Hence statement 3 is correct

Solution: C

Hence statement 1 is correct

Hence statement 2 is correct

Hence statement 3 is correct

• Question 9 of 30 9. Question 1 points With reference to the position of the Cocos Plate, which of the statement is correct? a) It is located to the east of the Pacific Plate and south of the North American Plate. b) It is located to the west of the Caribbean Plate and north of the Nazca Plate. c) It is located to the south of the Nazca Plate and east of the Pacific Plate. d) It is located to the north of the Antarctic Plate and west of the South American Plate. Correct Solution: B The Cocos Plate is a relatively small, triangular-shaped oceanic tectonic plate located beneath the Pacific Ocean off the west coast of Central America. Named after Cocos Island (the only emergent island within its boundaries), this plate plays a crucial role in shaping the geological dynamics of Central America through its interactions with neighbouring plates. Incorrect Solution: B The Cocos Plate is a relatively small, triangular-shaped oceanic tectonic plate located beneath the Pacific Ocean off the west coast of Central America. Named after Cocos Island (the only emergent island within its boundaries), this plate plays a crucial role in shaping the geological dynamics of Central America through its interactions with neighbouring plates.

#### 9. Question

With reference to the position of the Cocos Plate, which of the statement is correct?

• a) It is located to the east of the Pacific Plate and south of the North American Plate.

• b) It is located to the west of the Caribbean Plate and north of the Nazca Plate.

• c) It is located to the south of the Nazca Plate and east of the Pacific Plate.

• d) It is located to the north of the Antarctic Plate and west of the South American Plate.

Solution: B

The Cocos Plate is a relatively small, triangular-shaped oceanic tectonic plate located beneath the Pacific Ocean off the west coast of Central America. Named after Cocos Island (the only emergent island within its boundaries), this plate plays a crucial role in shaping the geological dynamics of Central America through its interactions with neighbouring plates.

Solution: B

• Question 10 of 30 10. Question 1 points Consider the following statements regarding transform boundaries: Statement I: Transform boundaries are conservative plate margins where plates slide past each other without creating or destroying lithosphere. Statement II: The San Andreas Fault is a transform boundary characterized by shallow-focus earthquakes and the absence of volcanic activity. 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, but 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. Correct Solution: B Transform plate boundaries, also known as conservative plate boundaries, with their associated transform faults occur where lithospheric plates slide past each other and where the crust is neither destroyed nor formed. Hence statement 1 is correct The San Andreas Fault, a transform boundary, is known for shallow-focus earthquakes and the absence of volcanic activity, as it’s where the Pacific and North American plates slide horizontally past each other. This type of movement along a transform boundary often results in shallow-focus earthquakes, meaning the earthquakes originate relatively close to the Earth’s surface. Unlike convergent boundaries (where plates collide) or divergent boundaries (where plates move apart), transform boundaries typically don’t exhibit significant volcanic activity. The San Andreas Fault is a strike-slip fault, where the movement is primarily horizontal, or right-lateral, meaning the side you are standing on moves to the right as you face the fault. The San Andreas Fault runs through California, forming the boundary between the Pacific and North American plates. Hence statement 2 is correct Second statement is an example for first statement. Hence, option (b) is correct. Incorrect Solution: B Transform plate boundaries, also known as conservative plate boundaries, with their associated transform faults occur where lithospheric plates slide past each other and where the crust is neither destroyed nor formed. Hence statement 1 is correct The San Andreas Fault, a transform boundary, is known for shallow-focus earthquakes and the absence of volcanic activity, as it’s where the Pacific and North American plates slide horizontally past each other. This type of movement along a transform boundary often results in shallow-focus earthquakes, meaning the earthquakes originate relatively close to the Earth’s surface. Unlike convergent boundaries (where plates collide) or divergent boundaries (where plates move apart), transform boundaries typically don’t exhibit significant volcanic activity. The San Andreas Fault is a strike-slip fault, where the movement is primarily horizontal, or right-lateral, meaning the side you are standing on moves to the right as you face the fault. The San Andreas Fault runs through California, forming the boundary between the Pacific and North American plates. Hence statement 2 is correct Second statement is an example for first statement. Hence, option (b) is correct.

#### 10. Question

Consider the following statements regarding transform boundaries:

Statement I: Transform boundaries are conservative plate margins where plates slide past each other without creating or destroying lithosphere.

Statement II: The San Andreas Fault is a transform boundary characterized by shallow-focus earthquakes and the absence of volcanic activity.

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, but 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.

Solution: B

Transform plate boundaries, also known as conservative plate boundaries, with their associated transform faults occur where lithospheric plates slide past each other and where the crust is neither destroyed nor formed.

Hence statement 1 is correct

The San Andreas Fault, a transform boundary, is known for shallow-focus earthquakes and the absence of volcanic activity, as it’s where the Pacific and North American plates slide horizontally past each other.

This type of movement along a transform boundary often results in shallow-focus earthquakes, meaning the earthquakes originate relatively close to the Earth’s surface.

Unlike convergent boundaries (where plates collide) or divergent boundaries (where plates move apart), transform boundaries typically don’t exhibit significant volcanic activity.

The San Andreas Fault is a strike-slip fault, where the movement is primarily horizontal, or right-lateral, meaning the side you are standing on moves to the right as you face the fault.

The San Andreas Fault runs through California, forming the boundary between the Pacific and North American plates.

Hence statement 2 is correct

Second statement is an example for first statement.

Hence, option (b) is correct.

Solution: B

Hence statement 1 is correct

This type of movement along a transform boundary often results in shallow-focus earthquakes, meaning the earthquakes originate relatively close to the Earth’s surface.

Unlike convergent boundaries (where plates collide) or divergent boundaries (where plates move apart), transform boundaries typically don’t exhibit significant volcanic activity.

The San Andreas Fault is a strike-slip fault, where the movement is primarily horizontal, or right-lateral, meaning the side you are standing on moves to the right as you face the fault.

The San Andreas Fault runs through California, forming the boundary between the Pacific and North American plates.

Hence statement 2 is correct

Second statement is an example for first statement.

Hence, option (b) is correct.

• Question 11 of 30 11. Question 1 points Consider the following statements : Spring tides occur when the sun, the moon and the Earth lie in a straight line. Spring tides can occur only on New moon and full moon periods. 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 Correct Solution: C The position of both the sun and the moon in relation to the Earth has direct impact on the height of tides. When the sun, the moon and the Earth lie in a straight line, the height of the tide will be higher. During these alignments, the gravitational pull of the sun and the moon combine, causing the ocean to bulge more than usual; hence these tides are also known as King tides. The tides form during this situation are called Spring tides. Spring tides occur twice a month, one on full moon period and another during New moon period. Hence statements 1 and 2 are correct Incorrect Solution: C The position of both the sun and the moon in relation to the Earth has direct impact on the height of tides. When the sun, the moon and the Earth lie in a straight line, the height of the tide will be higher. During these alignments, the gravitational pull of the sun and the moon combine, causing the ocean to bulge more than usual; hence these tides are also known as King tides. The tides form during this situation are called Spring tides. Spring tides occur twice a month, one on full moon period and another during New moon period. Hence statements 1 and 2 are correct

#### 11. Question

Consider the following statements :

• Spring tides occur when the sun, the moon and the Earth lie in a straight line.

• Spring tides can occur only on New moon and full moon periods.

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

Solution: C

• The position of both the sun and the moon in relation to the Earth has direct impact on the height of tides.

• When the sun, the moon and the Earth lie in a straight line, the height of the tide will be higher.

• During these alignments, the gravitational pull of the sun and the moon combine, causing the ocean to bulge more than usual; hence these tides are also known as King tides.

• The tides form during this situation are called Spring tides.

• Spring tides occur twice a month, one on full moon period and another during New moon period.

Hence statements 1 and 2 are correct

Solution: C

• The position of both the sun and the moon in relation to the Earth has direct impact on the height of tides.

• When the sun, the moon and the Earth lie in a straight line, the height of the tide will be higher.

• During these alignments, the gravitational pull of the sun and the moon combine, causing the ocean to bulge more than usual; hence these tides are also known as King tides.

• The tides form during this situation are called Spring tides.

• Spring tides occur twice a month, one on full moon period and another during New moon period.

Hence statements 1 and 2 are correct

• Question 12 of 30 12. Question 1 points Consider the following statements : Statement – I : Seawater in Hydrothermal vents are always boiling, thus increasing temperatures of surrounding water. Statement – II : Cold sea water is heated by hot Magma as it enters into Ocean crust through fissures and reemerge from hydrothermal vents. Which of the following is correct in respect of the above statements ? (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I (c) Statement- I is correct but Statement -II is incorrect (d) Statement- I is incorrect but Statement -II is correct Correct Solution : D Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents. Sea water in hydrothermal vents may reach temperature of over 700 Fahrenheit. Hot sea water in hydrocarmal vents does not boil because of the extreme pressure at the depths where the vents are formed. Hence statement 1 is incorrect Hydrothermal vents are the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centres or subduction zones (places on earth where two tectonic plates move away or towards one another). The cold sea water is heated by hot Magma and reemerges to form the vents. Hence statement 2 is correct Incorrect Solution : D Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents. Sea water in hydrothermal vents may reach temperature of over 700 Fahrenheit. Hot sea water in hydrocarmal vents does not boil because of the extreme pressure at the depths where the vents are formed. Hence statement 1 is incorrect Hydrothermal vents are the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centres or subduction zones (places on earth where two tectonic plates move away or towards one another). The cold sea water is heated by hot Magma and reemerges to form the vents. Hence statement 2 is correct

#### 12. Question

Consider the following statements :

Statement – I :

Seawater in Hydrothermal vents are always boiling, thus increasing temperatures of surrounding water.

Statement – II :

Cold sea water is heated by hot Magma as it enters into Ocean crust through fissures and reemerge from hydrothermal vents.

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

• (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I

• (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I

• (c) Statement- I is correct but Statement -II is incorrect

• (d) Statement- I is incorrect but Statement -II is correct

Solution : D

• Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents.

• Sea water in hydrothermal vents may reach temperature of over 700 Fahrenheit.

• Hot sea water in hydrocarmal vents does not boil because of the extreme pressure at the depths where the vents are formed.

Hence statement 1 is incorrect

• Hydrothermal vents are the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centres or subduction zones (places on earth where two tectonic plates move away or towards one another).

• The cold sea water is heated by hot Magma and reemerges to form the vents.

Hence statement 2 is correct

Solution : D

• Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents.

• Sea water in hydrothermal vents may reach temperature of over 700 Fahrenheit.

• Hot sea water in hydrocarmal vents does not boil because of the extreme pressure at the depths where the vents are formed.

Hence statement 1 is incorrect

• The cold sea water is heated by hot Magma and reemerges to form the vents.

Hence statement 2 is correct

• Question 13 of 30 13. Question 1 points Consider the following statements : Sea Groynes are formed by deposition of sediments by ocean currents. Sea Groynes are formed parallel to the direction of waves. 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 Correct Solution: D Sea Groynes are structures built perpendicular to the shore line extending to the sea. These are active structures that extends from the shore to the sea, most often perpendicular or slightly oblique to the shoreline. These are designed to reduce coastal erosion by trapping sand and sediment carried by currents. These are thus useful in stabilizing the beach and protecting the coast from impact of the sea. Adequate supply of sediment and existence of medium strong long shore sediment transport are major conditions of Groyne efficiency. Hence statements 1 and 2 are incorrect Incorrect Solution: D Sea Groynes are structures built perpendicular to the shore line extending to the sea. These are active structures that extends from the shore to the sea, most often perpendicular or slightly oblique to the shoreline. These are designed to reduce coastal erosion by trapping sand and sediment carried by currents. These are thus useful in stabilizing the beach and protecting the coast from impact of the sea. Adequate supply of sediment and existence of medium strong long shore sediment transport are major conditions of Groyne efficiency. Hence statements 1 and 2 are incorrect

#### 13. Question

Consider the following statements :

• Sea Groynes are formed by deposition of sediments by ocean currents.

• Sea Groynes are formed parallel to the direction of waves.

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

Solution: D

• Sea Groynes are structures built perpendicular to the shore line extending to the sea.

• These are active structures that extends from the shore to the sea, most often perpendicular or slightly oblique to the shoreline.

• These are designed to reduce coastal erosion by trapping sand and sediment carried by currents.

• These are thus useful in stabilizing the beach and protecting the coast from impact of the sea.

• Adequate supply of sediment and existence of medium strong long shore sediment transport are major conditions of Groyne efficiency.

Hence statements 1 and 2 are incorrect

Solution: D

• Sea Groynes are structures built perpendicular to the shore line extending to the sea.

• These are active structures that extends from the shore to the sea, most often perpendicular or slightly oblique to the shoreline.

• These are designed to reduce coastal erosion by trapping sand and sediment carried by currents.

• These are thus useful in stabilizing the beach and protecting the coast from impact of the sea.

• Adequate supply of sediment and existence of medium strong long shore sediment transport are major conditions of Groyne efficiency.

Hence statements 1 and 2 are incorrect

• Question 14 of 30 14. Question 1 points Consider the following statements : Continental shelf is the extension of continental land mass to the continental edge, characterized by uniform width across all oceans. Continental shelves are richest fishing grounds globally. The limited depth and gentle slope of continental shelves increase height of the tides creating problem for shipping. Which of the statements given above is/are correct? (a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (d) 1, 2 and 3 Correct Solution: B Continental shelf is the seaward extension of the continent from the shoreline to the continental edge marked, approximately by 600 feet isobath The continental shelf is a shallow platform whose width varies greatly; from a few miles in North Pacific off the continent of North America to over 100 miles off Northwest Europe. Hence statement 1 is incorrect The shallowness of continental Shelves enable sunlight to penetrate through the water which encourages the growth of minute plants and other microscopic organisms. They are the rich in plankton on which millions of surface and bottom feeding fishes thrive. These are therefore the richest fishing grounds in the world. Hence statement 2 is correct The Limited depth and gentle slope of continental shelves keep out cold under currents and increase the height of tides This sometimes hinders shipping and other Marine activities since ships can only enter and leave port on the tide. Hence statement 3 is correct Incorrect Solution: B Continental shelf is the seaward extension of the continent from the shoreline to the continental edge marked, approximately by 600 feet isobath The continental shelf is a shallow platform whose width varies greatly; from a few miles in North Pacific off the continent of North America to over 100 miles off Northwest Europe. Hence statement 1 is incorrect The shallowness of continental Shelves enable sunlight to penetrate through the water which encourages the growth of minute plants and other microscopic organisms. They are the rich in plankton on which millions of surface and bottom feeding fishes thrive. These are therefore the richest fishing grounds in the world. Hence statement 2 is correct The Limited depth and gentle slope of continental shelves keep out cold under currents and increase the height of tides This sometimes hinders shipping and other Marine activities since ships can only enter and leave port on the tide. Hence statement 3 is correct

#### 14. Question

Consider the following statements :

• Continental shelf is the extension of continental land mass to the continental edge, characterized by uniform width across all oceans.

• Continental shelves are richest fishing grounds globally.

• The limited depth and gentle slope of continental shelves increase height of the tides creating problem for shipping.

Which of the statements given above is/are correct?

• (a) 1 and 3 only

• (b) 2 and 3 only

• (c) 1 and 2 only

• (d) 1, 2 and 3

Solution: B

• Continental shelf is the seaward extension of the continent from the shoreline to the continental edge marked, approximately by 600 feet isobath

• The continental shelf is a shallow platform whose width varies greatly; from a few miles in North Pacific off the continent of North America to over 100 miles off Northwest Europe.

Hence statement 1 is incorrect

• The shallowness of continental Shelves enable sunlight to penetrate through the water which encourages the growth of minute plants and other microscopic organisms.

• They are the rich in plankton on which millions of surface and bottom feeding fishes thrive.

• These are therefore the richest fishing grounds in the world.

Hence statement 2 is correct

• The Limited depth and gentle slope of continental shelves keep out cold under currents and increase the height of tides

• This sometimes hinders shipping and other Marine activities since ships can only enter and leave port on the tide.

Hence statement 3 is correct

Solution: B

• Continental shelf is the seaward extension of the continent from the shoreline to the continental edge marked, approximately by 600 feet isobath

• The continental shelf is a shallow platform whose width varies greatly; from a few miles in North Pacific off the continent of North America to over 100 miles off Northwest Europe.

Hence statement 1 is incorrect

• The shallowness of continental Shelves enable sunlight to penetrate through the water which encourages the growth of minute plants and other microscopic organisms.

• They are the rich in plankton on which millions of surface and bottom feeding fishes thrive.

• These are therefore the richest fishing grounds in the world.

Hence statement 2 is correct

• The Limited depth and gentle slope of continental shelves keep out cold under currents and increase the height of tides

• This sometimes hinders shipping and other Marine activities since ships can only enter and leave port on the tide.

Hence statement 3 is correct

• Question 15 of 30 15. Question 1 points Consider the following statements : Statement – I : Most tsunamis are generated by underwater earthquakes with magnitudes over 7.0 Statement – II : Earthquakes with magnitude over 7.0 occurring under or very near the ocean are most likely to trigger displacement of ocean floor. Which of the following is correct in respect of the above statements ? (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I (c) Statement- I is correct but Statement -II is incorrect (d) Statement- I is incorrect but Statement -II is correct Correct Solution : A Volcano, earthquakes and landslides are most common causes of Tsunami. Tsunamis can be generated by earthquakes on normal, strike-slip and reverse faults. If big enough and close enough to the ocean floor, the energy from such an earthquake can cause the ocean floor to suddenly rise (uplift) or fall (subside); this sudden vertical displacement of the ocean floor typically sets a Tsunami into motion. As the ocean floor rises or false so does the water above it as the water moves up and down to regain its balance a Tsunami is born. Not all earthquakes cause tsunamis; key earthquake characteristics that contribute to Tsunami generation are location, magnitude and depth. Most tsunamis are generated by earthquakes with magnitude over 7.0 that occur under or very near the ocean and less than 100 km or 62 miles below the Earth’s surface (as earthquakes deeper than this are unlikely to displace the ocean floor). Generally an earthquake must exceed magnitude 8.0 to generate a dangerous distant Tsunami Most of the tsunamis (about 89%) in the history of Tsunami formation have been generated by large earthquakes or landslides caused by earthquakes. Hence statements 1 and 2 are correct and statement 2 correctly explains statement 1 Incorrect Solution : A Volcano, earthquakes and landslides are most common causes of Tsunami. Tsunamis can be generated by earthquakes on normal, strike-slip and reverse faults. If big enough and close enough to the ocean floor, the energy from such an earthquake can cause the ocean floor to suddenly rise (uplift) or fall (subside); this sudden vertical displacement of the ocean floor typically sets a Tsunami into motion. As the ocean floor rises or false so does the water above it as the water moves up and down to regain its balance a Tsunami is born. Not all earthquakes cause tsunamis; key earthquake characteristics that contribute to Tsunami generation are location, magnitude and depth. Most tsunamis are generated by earthquakes with magnitude over 7.0 that occur under or very near the ocean and less than 100 km or 62 miles below the Earth’s surface (as earthquakes deeper than this are unlikely to displace the ocean floor). Generally an earthquake must exceed magnitude 8.0 to generate a dangerous distant Tsunami Most of the tsunamis (about 89%) in the history of Tsunami formation have been generated by large earthquakes or landslides caused by earthquakes. Hence statements 1 and 2 are correct and statement 2 correctly explains statement 1

#### 15. Question

Consider the following statements :

Statement – I :

Most tsunamis are generated by underwater earthquakes with magnitudes over 7.0

Statement – II :

Earthquakes with magnitude over 7.0 occurring under or very near the ocean are most likely to trigger displacement of ocean floor.

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

• (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I

• (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I

• (c) Statement- I is correct but Statement -II is incorrect

• (d) Statement- I is incorrect but Statement -II is correct

Solution : A

• Volcano, earthquakes and landslides are most common causes of Tsunami.

• Tsunamis can be generated by earthquakes on normal, strike-slip and reverse faults.

• If big enough and close enough to the ocean floor, the energy from such an earthquake can cause the ocean floor to suddenly rise (uplift) or fall (subside); this sudden vertical displacement of the ocean floor typically sets a Tsunami into motion.

• As the ocean floor rises or false so does the water above it as the water moves up and down to regain its balance a Tsunami is born.

• Not all earthquakes cause tsunamis; key earthquake characteristics that contribute to Tsunami generation are location, magnitude and depth.

• Most tsunamis are generated by earthquakes with magnitude over 7.0 that occur under or very near the ocean and less than 100 km or 62 miles below the Earth’s surface (as earthquakes deeper than this are unlikely to displace the ocean floor).

• Generally an earthquake must exceed magnitude 8.0 to generate a dangerous distant Tsunami

• Most of the tsunamis (about 89%) in the history of Tsunami formation have been generated by large earthquakes or landslides caused by earthquakes.

Hence statements 1 and 2 are correct and statement 2 correctly explains statement 1

Solution : A

• Volcano, earthquakes and landslides are most common causes of Tsunami.

• Tsunamis can be generated by earthquakes on normal, strike-slip and reverse faults.

• As the ocean floor rises or false so does the water above it as the water moves up and down to regain its balance a Tsunami is born.

• Not all earthquakes cause tsunamis; key earthquake characteristics that contribute to Tsunami generation are location, magnitude and depth.

• Generally an earthquake must exceed magnitude 8.0 to generate a dangerous distant Tsunami

• Most of the tsunamis (about 89%) in the history of Tsunami formation have been generated by large earthquakes or landslides caused by earthquakes.

Hence statements 1 and 2 are correct and statement 2 correctly explains statement 1

• Question 16 of 30 16. Question 1 points With reference to various Geophysical phenomena, Rogue Waves are : (a) Waves whose origin depends on astronomical reasons. (b) Very Fast waves that run parallel to the coast bringing sediments and deposit them. (c) Deep water waves that generate cyclones that cause mass destruction. (d) Waves that are greater than twice the size of surrounding waves, forming from directions other than prevailing winds. Correct Solution : D Rogue Waves also called extreme storm waves by scientists, are waves which are greater than twice the size of surrounding waves These are very unpredictable and often come unexpectedly from directions other than prevailing wind and waves Most reports of such waves say that they look like walls of water often steep sided with unusually deep troughs. Extreme waves often form because swells while travelling across the ocean, do so at different speeds and directions; as the swells pass through one another their crests, troughs and length sometimes coincide and reinforce each other. This process can form unusually large towering waves that quickly disappear ; if the swells are travelling in the same direction, these mountainous waves last for several minutes before subsiding. Hence option D is correct Incorrect Solution : D Rogue Waves also called extreme storm waves by scientists, are waves which are greater than twice the size of surrounding waves These are very unpredictable and often come unexpectedly from directions other than prevailing wind and waves Most reports of such waves say that they look like walls of water often steep sided with unusually deep troughs. Extreme waves often form because swells while travelling across the ocean, do so at different speeds and directions; as the swells pass through one another their crests, troughs and length sometimes coincide and reinforce each other. This process can form unusually large towering waves that quickly disappear ; if the swells are travelling in the same direction, these mountainous waves last for several minutes before subsiding. Hence option D is correct

#### 16. Question

With reference to various Geophysical phenomena, Rogue Waves are :

• (a) Waves whose origin depends on astronomical reasons.

• (b) Very Fast waves that run parallel to the coast bringing sediments and deposit them.

• (c) Deep water waves that generate cyclones that cause mass destruction.

• (d) Waves that are greater than twice the size of surrounding waves, forming from directions other than prevailing winds.

Solution : D

• Rogue Waves also called extreme storm waves by scientists, are waves which are greater than twice the size of surrounding waves

• These are very unpredictable and often come unexpectedly from directions other than prevailing wind and waves

• Most reports of such waves say that they look like walls of water often steep sided with unusually deep troughs.

• Extreme waves often form because swells while travelling across the ocean, do so at different speeds and directions; as the swells pass through one another their crests, troughs and length sometimes coincide and reinforce each other.

• This process can form unusually large towering waves that quickly disappear ; if the swells are travelling in the same direction, these mountainous waves last for several minutes before subsiding.

Hence option D is correct

Solution : D

• Rogue Waves also called extreme storm waves by scientists, are waves which are greater than twice the size of surrounding waves

• These are very unpredictable and often come unexpectedly from directions other than prevailing wind and waves

• Most reports of such waves say that they look like walls of water often steep sided with unusually deep troughs.

Hence option D is correct

• Question 17 of 30 17. Question 1 points Consider the following statements: Statement – I : Equatorial regions have the highest oceanic salinity. Statement – II : Equatorial regions experience high temperature and high rates of evaporation throughout the year. Which of the following is correct in respect of the above statements? (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I (c) Statement- I is correct but Statement -II is incorrect (d) Statement- I is incorrect but Statement -II is correct Correct Solution : D The salinity of normal open ocean ranges between 33 o/oo and 37o/oo. In general, salinity gradually decreases towards the poles. Equatorial regions are supposed to have higher salinity due to evaporation and high temperature; but this is balanced by large amount of precipitation. In the equatorial region, salinity is actually low, due to higher amount of rainfall Also, this region is drained by various large rivers that bring freshwater into the ocean Consequently, the combination of increased rainfall, higher relative humidity, cloud cover and the influx of freshwater result in lower salinity levels. At the equator, the surface salinity in Oceans is low due to high rainfall and the movement of water through equatorial currents; however, beneath surface, higher salinity levels are observed. Hence statement 1 is incorrect but statement 2 is correct Incorrect Solution : D The salinity of normal open ocean ranges between 33 o/oo and 37o/oo. In general, salinity gradually decreases towards the poles. Equatorial regions are supposed to have higher salinity due to evaporation and high temperature; but this is balanced by large amount of precipitation. In the equatorial region, salinity is actually low, due to higher amount of rainfall Also, this region is drained by various large rivers that bring freshwater into the ocean Consequently, the combination of increased rainfall, higher relative humidity, cloud cover and the influx of freshwater result in lower salinity levels. At the equator, the surface salinity in Oceans is low due to high rainfall and the movement of water through equatorial currents; however, beneath surface, higher salinity levels are observed. Hence statement 1 is incorrect but statement 2 is correct

#### 17. Question

Consider the following statements:

Statement – I :

Equatorial regions have the highest oceanic salinity.

Statement – II :

Equatorial regions experience high temperature and high rates of evaporation throughout the year.

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

• (a) Both Statement -I and Statement -II are correct and Statement -II explains Statement -I

• (b) Both Statement -I and Statement -II are correct but Statement -II does not explain Statement -I

• (c) Statement- I is correct but Statement -II is incorrect

• (d) Statement- I is incorrect but Statement -II is correct

Solution : D

• The salinity of normal open ocean ranges between 33 o/oo and 37o/oo.

• In general, salinity gradually decreases towards the poles.

• Equatorial regions are supposed to have higher salinity due to evaporation and high temperature; but this is balanced by large amount of precipitation.

• In the equatorial region, salinity is actually low, due to higher amount of rainfall

• Also, this region is drained by various large rivers that bring freshwater into the ocean

• Consequently, the combination of increased rainfall, higher relative humidity, cloud cover and the influx of freshwater result in lower salinity levels.

• At the equator, the surface salinity in Oceans is low due to high rainfall and the movement of water through equatorial currents; however, beneath surface, higher salinity levels are observed.

Hence statement 1 is incorrect but statement 2 is correct