Interior structure of the earth MCQ Quiz - Objective Question with Answer for Interior structure of the earth - Download Free PDF

The correct answer is aquifer.

Key Points

• The groundwater stored between layers of hard rock below the water table is called aquifer.
• An aquifer is a saturated zone beneath the water table.
• It is a body of porous rock or sediment saturated with groundwater.
• Groundwater enters an aquifer as precipitation seeps through the soil.
• It can move through the aquifer and resurface through springs and wells.
• There are two general types of aquifers: confined and unconfined.
  • Confined aquifers have a layer of impenetrable rock or clay above them, while unconfined aquifers lie below a permeable layer of soil. 
• Aquifers are typically made up of gravel, sand, sandstone, or fractured rock, like limestone.
• Water can move through these materials because they have large connected spaces that make them permeable.

Additional Information

• Groundwater resources:
  • ​It is the water found underground in the cracks and spaces in soil, sand, and rocks.
  • It is stored in and moves slowly through the geological formation of soil, sand, and rocks called aquifers.
  • The total replenishable groundwater resources in the country are about 432 cubic km.

The correct answer is Calderas volcanoes.

• Calderas volcanoes are an example of the most explosive type of volcano.

Key Points

• Caldera Volcanoes:
  • Calderas Volcanoes are known as the most explosive volcanoes on Earth.
  • When they erupt, they incline to drop on themselves rather than constructing any structure.
  • The fallen depressions are known as calderas.

​

Additional Information

•  Volcanoes:
  • A volcano is a vent or fissure in Earth’s crust through which lava, ash, rocks, and gases erupt.
• The other types of volcanoes are Shield Volcanoes and  Composite Volcanoes. 
• Shield volcanoes:
  • These are the largest of all the volcanoes on the earth.
  • These volcanoes are made up of basalt.
  • Eg: Hawaiian shield volcanoes.
• Flood Basalt volcanoes:
  • These volcanoes discharge highly fluid lava that flows for long distances.
  • Most parts of the world are covered by thick basalt lava flows.

The correct answer is Hypocentre.

Key Points

• The focus is the point within the earth where an earthquake rupture starts.
• It is also termed as the hypocenter.
• The epicenter is the point on the earth's surface vertically above the hypocenter.
• The epicenter can be located by computing arcs from each of three or more seismic observatories.
• The point of intersection of the arcs marks the epicenter.

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Important Points

Immediate Effects of Earthquake:

• Ground Shaking
• Differential ground settlement
• Land and mud slides
• Soil liquefaction
• Ground lurching
• Avalanches
• Ground Displacement
• Floods from dam and levee failures
• Fires
• Structural collapse
• Falling objects
• Tsunami

Key Points

• The Earth's crust is the outermost layer, and its thickness varies from about 5 to 70 kilometers. It does not extend to a depth of 2900 km. Hence, option 1 is incorrect.
• The Earth's mantle lies beneath the crust and extends from a depth of about 30 km to approximately 2900 km. Hence, option 2 is correct.
• The Earth's core starts at a depth of around 2900 km and extends to the center of the Earth (about 6371 km). It consists mainly of iron and nickel. Hence, option 3 is incorrect.

The correct answer is oxides, sulphides and carbonates.

Key Points

• Metal ores in the Earth's crust are commonly found in the form of oxides, sulphides, and carbonates.
• Oxides include minerals like hematite (Fe₂O₃) and bauxite (Al₂O₃·2H₂O).
• Sulphides include minerals such as galena (PbS) and pyrite (FeS₂).
• Carbonates include minerals like calcite (CaCO₃) and dolomite (CaMg(CO₃)₂).
• These forms are the primary sources for extracting metals in various mining processes.

Additional Information

• Oxides: These are compounds of oxygen and metals. They are typically formed through the oxidation process.
• Sulphides: These are compounds of sulfur with metals. They are generally formed in reducing environments, like hydrothermal vents.
• Carbonates: These are salts of carbonic acid containing the carbonate ion (CO₃^2-). They are usually formed in sedimentary environments.
• Mining and Extraction: The process of obtaining metals from ores involves various techniques like smelting, electrolysis, and chemical reduction.
• Economic Importance: The extraction of metals from these ores is crucial for various industries including construction, electronics, and manufacturing.

The correct answer is outer core.

Important Points

• The interior of the earth is divided into three parts namely Crust, Mantle, and Core.
• The core is the innermost layer of the earth.
• The radius of the innermost layer(core) is about 3500 km.
• The core is made up of material constituted by nickel and iron.
• The temperature and pressure of the central core are very high.

Key Points

• The core is further subdivided into two layers called the outer core and inner core.
• The outer core of the earth is in a liquid state.
• The inner core is in solid-state
• The outer core is responsible for the earth's magnetic field.

Additional Information

• The crust is the outermost of the earth.
  • It is brittle in nature.
  • it the thinnest layer of Earth.
  • The thickness of the crust varies under the oceanic and continental areas.
• The mantle is the second layer in the interior of the earth.
  • The mantle extends from Moho’s discontinuity to a depth of 2,900 km.
  • The upper portion of the mantle is called the asthenosphere.

The correct answer is 4.

Important Points

• Based on historical seismic activity, the Bureau of Indian Standards has categorized regions in India into four seismic zones: zones II, III, IV and V.
• Of these, the most seismically active area is Zone V and the least active is Zone II. 
• There is a history of devastating earthquakes on the Indian subcontinent.
• The key cause for the high frequency and severity of earthquakes is that the Indian plate is driving into Asia at a rate of roughly 47 mm/year.
• India's geological figures indicate that about 54 percent of the land is prone to earthquakes.
• Research by the World Bank and the United Nations predicts that by 2050, about 200 million urban dwellers in India will be vulnerable to storms and earthquakes.
• The most recent edition of India's seismic zoning map given in India's earthquake-resistant design code [IS 1893 (Part 1) 2002] assigns four degrees of seismicity in terms of zone factors for India.
• In other words, unlike its previous edition, which consisted of five or six zones for the region, India's earthquake zoning map divides India into four seismic zones (Zone 2, 3, 4, and 5).
• According to the new zoning map, the maximum degree of seismicity is predicted in Zone 5, while the lowest level of seismicity is correlated with Zone 2.

Revised earthquake hazard zone map of India

Option 2 is correct, i.e. Aluminium.

Key Points

• Aluminium is the most plentiful (most abundant) of metals in the crust of the earth.
• Aluminium is around 8.1 per cent of the total metals on the surface of the earth.

Important Points

• The most plentiful non-metal in the earth's surface is Oxygen.
• The most plentiful metalloid in the crust of the earth is Silicon.
• O > Si > Al > Fe > Ca are the most abundant elements in the earth crust.

The correct answer is 30 km.

Key Points

• Earth’s crust:
  • The interior of the earth is made up of several concentric layers which are the crust, the mantle, the outer core and the inner core.
  • The crust is the outermost layer of the earth making up 0.5-1.0% of the earth’s volume and less than 1% of Earth’s mass.
  • Materials that initially stayed in their liquid phase during this process, called “incompatible elements,” ultimately became Earth's brittle crust. 
  • The lower layer of the crust consists of basaltic and ultra-basic rocks.
  • Density increases with depth, and the average density is about 2.7 g/cm3 (the average density of the earth is 5.51 g/cm³).
  • The thickness of the crust varies in the range of 5-30 km in the case of the oceanic crust and 50-70 km in the case of the continental crust.
  • The mean thickness of the oceanic crust is approximately 7 km, while the mean thickness of the continental crust is about 35-40 km.

Important Points

The correct answer is Increases

Key Points

• A rise in temperature with an increase in depth is observed in mines and deep wells.
• These evidence along with molten lava erupted from the earth’s interior supports that the temperature increases towards the centre of the earth.
• While in the upper 100kms, the increase in temperature is at the rate of 120C per km and in the next 300kms, it is 200C per km. But going further deep, this rate reduces to a mere 100C per km.
• It is assumed that the rate of increase in the temperature beneath the surface is decreasing towards the centre.
• Temperature is always increasing from the earth’s surface towards the centre.
• The temperature at the centre is estimated to lie somewhere between 30000C and 50000C, maybe that much higher due to the chemical reactions under high-pressure conditions.

​

The correct answer is nickel and iron.

Key Points

Core:

• The innermost layer is the core with a radius of about 3500 km.
• The central core has a very high temperature and pressure.
• The inner core (1200 km) is in the solid state whereas the outer core (2300 km) is in the liquid state.
• The innermost layer is the core with a radius of about 3500 km and divided into Inner and Outer core.
• The inner core is with a radius of 350 km mainly made up of- nickel and iron. The innermost layer is also called ‘nife’ (ni - nickel and fe - ferrous- iron).

Additional Information

The Earth is divided into four main layers: the solid crust on the outside, the mantle, the outer core, and the inner core.

• All those layers are separated from each other through a transition zone.
• These transition zones are called discontinuities.
  • Conrad Discontinuity: It lies between the Upper crust and Lower crust.
  • Mohorovicic Discontinuity: It lies between crust and mantle.
  • Repiti Discontinuity: It lies between the Upper mantle and Lower mantle.
  • Gutenberg Discontinuity: It lies between core and mantle.
  • Lehman Discontinuity: It lies between the upper core and lower core.

Interior of the Earth:

Crust:

• The uppermost layer over the earth’s surface is called the crust.
• It is the thinnest of all the layers.
• on the continental masses, It is about 35 km and on the ocean floors, only 5 km.
• The crust is the thinnest layer of the Earth and it amounts to less than 1% of our planet's volume.
• The earth is made up of several concentric layers with one inside another, just like an onion.
• The crust is the outermost layer of Earth and is made up of igneous, metamorphic, and sedimentary rocks. 
• The Earth's crust is unstable because of the exogenic forces.

Mantle:

• The Mantle extends up to a depth of 2900 km below the crust.
• It is the widest section of the Earth.

The correct answer is Iron.

• Iron is the second most abundant metal in the earth's crust (5.0%).
• Aluminium is the most abundant metal found in the earth's crust (8.1%).
• Oxygen comprises of 46.6% of the total weight of the earth's crust.

Key Points

Elements in earth's crust

The correct answer is Rock.

Key Points

• Earth's crust 
  • Each fragment of the Earth's crust is known as a Plate.
  • Earth consists of three parts. 
    • The crust
    • The mantle
    • The core
  • The Crust is the outer layer of the Earth and it is very thin compared to the core and mantle. It is made up of igneous, sedimentary, and metamorphic rocks.
  • There are two types of crust viz oceanic and continental.
  • The mantle lies below the crust and it is up to 2900 km thick.
  • The core is the center of the earth.

The correct answer is Calderas volcanoes.

• Calderas volcanoes are an example of the most explosive type of volcano.

Key Points

• Caldera Volcanoes:
  • Calderas Volcanoes are known as the most explosive volcanoes on Earth.
  • When they erupt, they incline to drop on themselves rather than constructing any structure.
  • The fallen depressions are known as calderas.

​

Additional Information

•  Volcanoes:
  • A volcano is a vent or fissure in Earth’s crust through which lava, ash, rocks, and gases erupt.
• The other types of volcanoes are Shield Volcanoes and  Composite Volcanoes. 
• Shield volcanoes:
  • These are the largest of all the volcanoes on the earth.
  • These volcanoes are made up of basalt.
  • Eg: Hawaiian shield volcanoes.
• Flood Basalt volcanoes:
  • These volcanoes discharge highly fluid lava that flows for long distances.
  • Most parts of the world are covered by thick basalt lava flows.

The correct answer is 7.
Key Points

• The theory of plate tectonics proposes that the earth's lithosphere is divided into 7 major and 8 minor plates.
• The theory of plate tectonics is the modern update of Continental drift proposed by Alfred Wegener in 1912.
• The theory of plate tectonics explains the features and movement of the Earth's surface.
• In Plate tectonics, Earth’s outermost layer i.e. the lithosphere is broken into large rocky plates.
• Plate tectonics explains many events such as volcanoes, earthquakes, and the formation of mountains which are a result of Earth’s subterranean movements.
• The Lithosphere is made of the crust and upper mantle of the Earth and is 100km thick.

Additional Information

• The Largest plates are the Antarctic, Eurasian, and North American plates.
• Continental plates (up to 200km) are thicker than oceanic plates (50-100km).
• The Seven major plates are:

1. African,
2. Antarctic,
3. Eurasian,
4. North American,
5. South American,
6. India-Australian, and
7. The Pacific plates

​The Some of minor plates are:

• Arabian,
• Caribbean,
• Nazca, and
• Scotia plates.​