Earth Structure — Set 5
Geography · पृथ्वी की संरचना · Questions 41–50 of 50
Which of the following is an 'Indirect Source' of information about Earth's interior?
Correct Answer: B. Analysis of Meteors
Meteors are an indirect source. They are assumed to be formed from the same material as Earth. Analyzing them gives clues about Earth's core and mantle composition.
Who proposed the theory of Continental Drift, which laid the groundwork for understanding Earth's crust movement?
Correct Answer: A. Alfred Wegener
Alfred Wegener proposed the theory of Continental Drift in 1912. He suggested that continents were once joined in a supercontinent called Pangaea. This idea evolved into the modern theory of Plate Tectonics.
What force is believed to drive the movement of tectonic plates?
Correct Answer: D. Convection currents in the Mantle
Thermal convection currents in the Mantle are the primary driver. Heat from the core causes mantle rock to rise, cool, and sink. This cycle drags the overlying lithospheric plates.
The term 'Lithosphere' roughly translates to?
Correct Answer: A. Rock/Stone sphere
Lithosphere comes from the Greek word 'Lithos' meaning stone or rock. It refers to the rigid, rocky outer layer of Earth. It includes the crust and the solid upper mantle.
The term 'Barysphere' is sometimes used to refer to which part of the Earth?
Correct Answer: A. The Core
Barysphere refers to the central region of the Earth, the Core. The term is derived from 'barys' meaning heavy, referring to the heavy metals found there. It lies beneath the lithosphere and pyrosphere (mantle).
At what depth is the Gutenberg Discontinuity typically located?
Correct Answer: B. 2,900 km
The Gutenberg Discontinuity lies at a depth of 2,900 km. It marks the boundary between the solid silicate mantle and the liquid iron-nickel outer core. It causes a distinct change in seismic wave behavior.
In the analogy of a boiled egg, the 'White' corresponds to which Earth layer?
Correct Answer: B. Mantle
The 'White' of the egg corresponds to the Mantle. It is the thickest layer, similar to the egg white. The shell represents the Crust, and the yolk represents the Core.
In the analogy of a boiled egg, the 'Yolk' corresponds to which Earth layer?
Correct Answer: A. Core
The 'Yolk' corresponds to the Earth's Core. It is centrally located and distinct in composition from the surrounding white (mantle). It represents the dense center of the planet.
The scientific study of the internal structure of the Earth using earthquake waves is called?
Correct Answer: D. Seismology
Seismology is the study of earthquakes and seismic waves. It is the primary method used to map the Earth's interior. By analyzing how waves refract and reflect, scientists determine layer properties.
How does high pressure affect the melting point of iron in the Inner Core?
Correct Answer: A. It increases the melting point
High pressure increases the melting point of iron. In the Inner Core, the pressure is so immense that the melting point of iron exceeds the actual temperature. This keeps the iron in a solid state.