Question 1

Consider the following as sources of information about the Earth's interior:
1. Material from the Kola deep drill project
2. Analysis of magma from volcanic eruptions
3. Study of meteors that reach the Earth
4. Data from magnetic surveys
How many of the above are considered 'direct sources' of information?

Accepted Answer

Only two. Statement 1 is correct; material collected from deep drilling projects like the one at Kola (Arctic Ocean) is a direct source of information. Statement 2 is correct; magma thrown onto the surface during a volcanic eruption is a direct source as it can be physically collected and analyzed in a laboratory. Statement 3 is incorrect; the analysis of meteors is considered an indirect source, based on the inference that their material and structure are similar to Earth's. Statement 4 is incorrect; magnetic surveys, like gravity and seismic activity, are classified as indirect sources that provide information about the distribution of materials without physical sampling from the interior.

Question 2

Consider the following rows regarding the structure of the Earth:
Row 1: Asthenosphere - The 'weak' upper portion of the mantle extending up to 400 km, which is the main source of magma.
Row 2: Oceanic Crust - The thinner component of the Earth's crust with a mean thickness of around 30 km.
Row 3: Inner Core - The solid, innermost layer of the Earth composed primarily of nickel and iron (nife).
In how many of the above rows is the information correctly matched?

Accepted Answer

Only two rows. Row 1 is correctly matched. The text explicitly states the upper portion of the mantle is the asthenosphere, meaning 'weak', extending up to 400 km, and is the main source of magma. Row 2 is incorrectly matched. This is a 'Numerical Swap' trap. The text states the mean thickness of oceanic crust is 5 km, while the continental crust is around 30 km. The row incorrectly assigns the continental crust's thickness to the oceanic crust. Row 3 is correctly matched. The text confirms that the inner core is in a solid state and is composed of heavy material, mostly nickel and iron, referred to as the 'nife' layer. Therefore, only two rows (Row 1 and Row 3) are correctly matched.

Question 3

Consider the following statements regarding earthquakes:
1. P-waves, also known as 'primary waves', are similar in nature to sound waves.
2. An important characteristic of S-waves is that they can travel through gaseous, liquid, and solid materials.
3. The point on the surface nearest to the focus is called the hypocenter.

How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is correct. The source material identifies P-waves as 'primary waves' and notes their similarity to sound waves. Statement 2 is incorrect. This is a property swap. The text specifies that S-waves can travel *only* through solid materials. The ability to travel through gaseous, liquid, and solid materials is a characteristic of P-waves. Statement 3 is incorrect. This is a terminology swap. The point on the surface nearest to the focus is the *epicenter*. The hypocenter is the focus itself, located within the Earth where energy is released.

Question 4

Consider the following statements regarding earthquakes:
1. All natural earthquakes take place in the lithosphere, which constitutes a depth of up to 200 km from the Earth's surface.
2. As seismic waves encounter materials of increasing density, their velocity decreases.
3. Surface waves are generated at the focus of the earthquake and are typically the first to be recorded by a seismograph.

How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is correct. The text specifies that all natural earthquakes occur in the lithosphere and defines the lithosphere as the portion of depth extending up to 200 km from the surface. Statement 2 is incorrect. This statement reverses the described relationship. The text states, 'The denser the material, the higher is the velocity' of the waves. Therefore, velocity increases with density. Statement 3 is incorrect. This statement contains two errors. First, surface waves are not generated at the focus (hypocenter); they are generated when body waves interact with surface rocks. Second, they are the *last* to be recorded by a seismograph, not the first.

Question 5

Consider the following rows matching earthquake wave characteristics:
Row 1: P-wave | Vibration perpendicular to propagation | Creates troughs and crests
Row 2: S-wave | Travels only through solids | Arrives after P-waves at the seismograph
Row 3: Surface Wave | Generated at the hypocenter | Most destructive due to high velocity

In how many of the above rows is the information correctly matched?

Accepted Answer

Only one row. Row 1 is incorrectly matched. P-waves vibrate *parallel* to the direction of propagation, causing stretching and squeezing. It is S-waves (and surface waves) that vibrate perpendicular to the direction of propagation and create troughs and crests.
Row 2 is correctly matched. The text confirms two key facts about S-waves: they can travel *only* through solid materials, and they arrive at the surface with a time lag after the P-waves.
Row 3 is incorrectly matched. Surface waves are not generated at the hypocenter; they are generated when body waves interact with the surface rocks. While they are the most destructive, it is not due to high velocity; they are the last and slowest waves to be recorded on a seismograph. Their destructive power comes from causing significant displacement of rocks along the surface. Therefore, only one row is correctly matched.

Question 6

Consider the following statements regarding the shadow zones of earthquake waves:
1. The shadow zone for S-waves is a narrow band located between 105° and 145° from the epicentre.
2. The shadow zone of P-waves is larger in extent than that of S-waves, covering over 40% of the Earth's surface.
3. Seismographs located beyond 145° from the epicentre record the arrival of both P-waves and S-waves.
How many of the statements given above are correct?

Accepted Answer

None. Statement 1 is incorrect. The shadow zone appearing as a band between 105° and 145° from the epicentre is characteristic of P-waves, not S-waves. The shadow zone for S-waves encompasses the entire area beyond 105° from the epicentre. Statement 2 is incorrect. The shadow zone of S-waves is significantly larger than that of P-waves. It is the S-wave shadow zone, not the P-wave one, that covers a little over 40% of the Earth's surface. The statement reverses this relationship. Statement 3 is incorrect. Seismographs located beyond 145° from the epicentre record the arrival of P-waves only. S-waves are not recorded in this zone as it falls entirely within the S-wave shadow zone.

Question 7

Consider the following rows regarding the measurement and classification of earthquakes:
Row 1: Richter Scale - Measures visible damage - Range 1-12
Row 2: Tectonic Earthquake - Caused by explosions of chemical devices - Confined to areas of large reservoirs
Row 3: Mercalli Scale - Measures energy released - Range 0-10
In how many of the above rows is the information correctly matched?

Accepted Answer

No rows. Row 1 is incorrectly matched. The Richter scale measures the magnitude (energy released), not visible damage, and its scale is 0-10. The description provided (visible damage, range 1-12) corresponds to the Mercalli scale. Row 2 is incorrectly matched. Tectonic earthquakes are caused by the sliding of rocks along a fault plane. Earthquakes caused by chemical explosions are 'explosion earthquakes', and those in areas of large reservoirs are 'reservoir-induced earthquakes'. The row incorrectly combines elements of three different earthquake types. Row 3 is incorrectly matched. The Mercalli scale measures the intensity (visible damage), not the energy released, and its range is 1-12. The description provided (energy released, range 0-10) corresponds to the Richter scale. Since no row is correctly matched, the correct answer is (d).

Question 8

Consider the following pairs:
Row 1: Richter Scale : Measures the visible damage caused by an earthquake on a scale of 1-12.
Row 2: Tsunami Generation : Requires an earthquake magnitude greater than 5 on the Mercalli scale with an epicenter below oceanic waters.
Row 3: Collapse Earthquake : A tremor generated due to the sliding of rocks along a fault plane in mining areas.
In how many of the above rows is the information correctly matched?

Accepted Answer

None. Row 1 is incorrectly matched. The Richter scale measures the magnitude related to the energy released (scale 0-10). The Mercalli scale measures intensity based on visible damage (scale 1-12). The pair swaps the definitions. Row 2 is incorrectly matched. The text states that devastating effects are associated with a magnitude of more than 5 on the Richter scale, not the Mercalli scale. Row 3 is incorrectly matched. A collapse earthquake is caused by the collapse of roofs in underground mines. The sliding of rocks along a fault plane describes a tectonic earthquake. Therefore, none of the rows are correctly matched.

Question 9

Consider the following rows regarding volcanic types and their characteristics: Row 1: Shield Volcano : Characterised by eruptions of cooler and more viscous lavas. Row 2: Caldera : The most explosive type, often collapsing on itself to form a depression. Row 3: Flood Basalt Province : The Hawaiian volcanoes are the most famous examples. In how many of the above rows is the information correctly matched?

Accepted Answer

Only one. Row 1 is incorrectly matched. Shield volcanoes are made of basalt, a very fluid lava, not cooler and viscous lava. Cooler and more viscous lavas are characteristic of Composite Volcanoes. Row 2 is correctly matched. The text explicitly states that Calderas are the 'most explosive of the earth’s volcanoes' and that 'the collapsed depressions are called calderas'. Row 3 is incorrectly matched. The text identifies the Hawaiian volcanoes as the most famous examples of Shield Volcanoes, not Flood Basalt Provinces. The Deccan Traps are given as an example of a Flood Basalt Province. Therefore, only one row is correctly matched.

Question 10

Consider the following statements about volcanic landforms: 1. Composite volcanoes are characterized by low-explosivity and are built from highly fluid basaltic lava. 2. Shield volcanoes are the largest of all volcanoes on Earth and are formed from layers of pyroclastic material and ashes accumulated around the vent. 3. The asthenosphere, a weaker zone within the Earth's mantle, is the source from which molten rock materials find their way to the surface. How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is incorrect. It swaps the characteristics of Composite and Shield volcanoes. Composite volcanoes have explosive eruptions with cooler, viscous lava. Low-explosivity and fluid basaltic lava are features of Shield volcanoes. Statement 2 is incorrect. While Shield volcanoes are the largest (barring basalt flows), they are built from fluid lava flows, not layers of pyroclastic material and ash. The accumulation of pyroclastic material and ash is characteristic of Composite volcanoes. Statement 3 is correct. The text states that the mantle contains a weaker zone called the asthenosphere, and 'It is from this that the molten rock materials find their way to the surface.' Therefore, only one statement is correct.

Question 11

Consider the following rows regarding intrusive volcanic landforms. In how many of the rows is the intrusive form correctly matched with its description?

Row 1: Lopolith - A saucer-shaped, concave to the sky intrusive body.
Row 2: Phacolith - A wall-like structure formed when lava solidifies almost perpendicular to the ground.
Row 3: Sill - The cooled portion of magma chambers, appearing as large domes after denudation.

Accepted Answer

Only one row. A detailed analysis of each row reveals the correct count. Row 1 is correctly matched: A lopolith is described as a saucer-shaped, concave to the sky body. Row 2 is incorrectly matched: A wall-like structure that solidifies almost perpendicular to the ground is a dyke, not a phacolith. A phacolith is a wavy mass of intrusive rocks found at the base of synclines or top of anticlines. Row 3 is incorrectly matched: The cooled portion of magma chambers that appear as large domes after denudation are batholiths, not sills. A sill is a near-horizontal body of intrusive igneous rock. Therefore, only one row is correctly matched.

Question 12

Consider the following statements regarding intrusive volcanic landforms:

1. Batholiths are granitic bodies that appear on the surface only after denudational processes remove the overlying materials.
2. The domal hills of granite on the Karnataka plateau are definitively identified as exfoliated lacoliths.
3. Dykes, commonly found in western Maharashtra, are thick, near-horizontal deposits of intrusive igneous rocks.

Accepted Answer

Only one. Statement 1 is correct. Batholiths are large bodies of magmatic material that cool at great depths and are exposed at the surface only after the erosion of the overlying rocks. They are granitic in nature. Statement 2 is incorrect. The domal granite hills on the Karnataka plateau are examples of either lacoliths or batholiths. The use of the word 'definitively' makes the statement incorrect as the origin is not exclusively attributed to lacoliths. Statement 3 is incorrect. This statement commits a 'Terminology Swap'. While dykes are common in western Maharashtra, they are near-perpendicular, wall-like structures. The description 'thick, near-horizontal deposits' applies to sills. Therefore, only one statement is correct.

Question 13

Consider the following rows matching intrusive volcanic forms with their descriptions.

Row 1: Lopolith - A wavy mass of intrusive rocks found at the base of synclines or top of anticlines.
Row 2: Phacolith - A saucer-shaped intrusive body, concave to the sky.
Row 3: Sill - A thick, near-horizontal body of intrusive igneous rock.

In how many of the above rows is the given information correctly matched?

Accepted Answer

Only one row. This question involves a 'Terminology Swap' trap. Row 1 is incorrectly matched. A lopolith is a saucer-shaped body, concave to the sky. The description provided ('A wavy mass... at the base of synclines') actually defines a phacolith. Row 2 is incorrectly matched. A phacolith is a wavy mass of intrusive rock. The description provided ('A saucer-shaped intrusive body, concave to the sky') defines a lopolith. The definitions for lopolith and phacolith have been swapped. Row 3 is correctly matched. Sills are indeed thick, near-horizontal deposits of intrusive igneous rock, as distinct from thinner sheets. Therefore, only one row is correctly matched.

Question 14

Consider the following statements regarding seismic waves as recorded on a seismograph:
1. The arrival sequence is typically Surface waves, followed by S-waves, and finally P-waves.
2. The amplitude of ground motion is generally highest for P-waves and lowest for Surface waves.
3. The time gap between the arrival of P-waves and S-waves is utilized to determine the distance to the earthquake's epicenter.
How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Seismic waves arrive in a sequence determined by their velocity. P-waves are the fastest and arrive first, followed by the slower S-waves, and finally the slowest Surface waves. The statement reverses this established sequence. Statement 2 is incorrect. The amplitude of ground motion, which reflects shaking intensity, is lowest for P-waves. S-waves have a higher amplitude, and Surface waves have the highest amplitude, making them the most destructive. The statement inverts this relationship. Statement 3 is correct. The difference in arrival times between the faster P-waves and slower S-waves (the S-P interval) is directly proportional to the distance from the epicenter, making it a fundamental tool for locating earthquakes. Therefore, only one statement is correct.

Question 15

Consider the following statements regarding seismic wave shadow zones:
1. The shadow zone for S-waves is a direct consequence of the Earth's liquid outer core, which blocks their transmission.
2. A seismograph located at an angular distance of 150° from an earthquake's epicenter will record neither direct P-waves nor direct S-waves.
3. The shadow zone for P-waves exists between approximately 105° and 145° from the epicenter and is caused by refraction at the core-mantle boundary.
How many of the above statements are correct?

Accepted Answer

Only two. Statement 1 is correct. S-waves are shear waves that cannot propagate through liquids. The existence of a vast S-wave shadow zone beyond 105° from the epicenter is primary geophysical evidence that the Earth's outer core is in a liquid state, as it completely blocks these waves. Statement 2 is incorrect. A location at 150° is beyond the P-wave shadow zone (105°-145°). Therefore, it will record refracted P-waves that have passed through the Earth's core. However, since it is beyond 105°, it lies within the S-wave shadow zone and will not record any direct S-waves. The statement incorrectly claims that *neither* wave type would be recorded. Statement 3 is correct. The P-wave shadow zone is an annular ring located between approximately 105° and 145° from the epicenter. This zone is not created by blockage but by the significant refraction (bending) of P-waves as they enter and exit the liquid outer core at the core-mantle boundary. Therefore, only two of the statements are correct.

Question 16

Consider the following statements regarding seismic shadow zones:
1. The S-wave shadow zone is a direct consequence of P-waves being refracted by the liquid outer core.
2. A seismograph located at an angular distance of 115° from an earthquake's epicenter would record neither direct P-waves nor direct S-waves.
3. The P-wave shadow zone exists in an annular band between 105° and 145° from the epicenter.
How many of the above statements are correct?

Accepted Answer

Only two. Statement 1 is incorrect. This statement confuses the causes for the two different shadow zones. The S-wave shadow zone is caused by the liquid outer core completely blocking S-waves, which cannot travel through liquid. The P-wave shadow zone is caused by the refraction of P-waves at the core-mantle boundary. Statement 2 is correct. The P-wave shadow zone is from 105° to 145°, and the S-wave shadow zone is beyond 105°. An instrument at 115° falls into both shadow zones and would therefore record neither direct P-waves nor direct S-waves. Statement 3 is correct. The provided data explicitly defines the P-wave shadow zone as the region from 105° to 145° from the epicenter and notes its annular (ring-shaped) nature. Therefore, only two statements are correct.

Question 17

Consider the following rows matching intrusive volcanic features with their descriptions:
Row 1: Sill : A near-vertical, wall-like intrusion that cuts across the layers of country rock.
Row 2: Laccolith : A massive intrusive body at great depth, often acting as a source magma chamber.
Row 3: Dyke : A horizontal, tabular intrusion that has pushed between layers of country rock.
In how many of the above rows is the feature correctly matched with its description?

Accepted Answer

None of the rows. Row 1 is incorrectly matched. The description provided is for a Dyke, which is a discordant feature that cuts across rock layers. A Sill is a concordant, horizontal intrusion. Row 2 is incorrectly matched. The description provided is for a Batholith, which is the largest intrusive body and acts as a source magma chamber. A Laccolith is a smaller, dome-shaped intrusion. Row 3 is incorrectly matched. The description provided is for a Sill, which is a horizontal, concordant feature. A Dyke is a near-vertical, discordant feature. Since all three rows swap the definitions of the volcanic features, none of the rows are correctly matched.

Interior Of The Earth

Unlock All Questions