Chapter 1: Origin and Structure of the Ear (Set-3)
The nebular hypothesis was later modified into the solar nebula theory mainly to explain
A Sudden origin of planets
B Uniform size of planets
C Angular momentum distribution
D Constant planetary distances
The solar nebula theory addressed limitations of earlier hypotheses by explaining how most angular momentum is concentrated in planets while most mass remains in the Sun, making planetary motion scientifically plausible.
Which observation strongly supports Earth’s axial rotation rather than revolution
A Seasonal temperature change
B Variation in daylight duration
C Apparent daily movement of Sun
D Change in position of stars annually
The apparent daily movement of the Sun across the sky results from Earth’s rotation on its axis, not from its revolution around the Sun.
The concept of standard time is directly based on
A Latitudinal divisions
B Longitudinal divisions
C Climatic zones
D Altitudinal variation
Standard time is calculated using longitudes because Earth rotates 360 degrees in 24 hours, making each 15-degree longitude represent one hour difference.
Which part of the Earth’s interior is the thickest layer
A Crust
B Upper mantle
C Mantle
D Core
The mantle extends from the base of the crust to the outer core and constitutes the largest volume and thickness among Earth’s internal layers.
Which evidence of continental drift is based on ancient climatic conditions
A Matching coastlines
B Fossil distribution
C Glacial deposits
D Rock structures
Evidence of ancient glacial deposits in present-day tropical regions suggests continents were once located near polar areas, supporting continental drift theory.
Plate tectonic theory explains mountain building primarily through
A Volcanic accumulation
B Erosion and deposition
C Plate convergence
D Sea floor spreading
When tectonic plates converge, compressional forces cause crustal thickening, folding, and uplift, resulting in formation of major mountain ranges.
The zone of weakness in Earth’s crust where earthquakes originate frequently is called
A Rift zone
B Seismic belt
C Fault zone
D Fold belt
Fault zones are fractures in the crust where stress accumulates and is released suddenly, making them common locations for earthquake activity.
Which type of stress causes normal faults to develop
A Compressional stress
B Tensional stress
C Shear stress
D Hydrostatic stress
Normal faults form due to tensional forces that pull the crust apart, causing one block to move downward relative to the other.
Which igneous rock forms deep below the Earth’s surface and has very large crystals
A Basalt
B Obsidian
C Granite
D Pumice
Granite is an intrusive igneous rock that cools slowly beneath the surface, allowing large crystals to develop.
Which sedimentary rock is formed from compacted clay particles
A Sandstone
B Limestone
C Shale
D Conglomerate
Shale forms from fine clay sediments deposited in calm water environments, later compacted into thinly layered sedimentary rock.
Metamorphism that affects large regions due to plate collision is known as
A Contact metamorphism
B Dynamic metamorphism
C Regional metamorphism
D Hydrothermal metamorphism
Regional metamorphism occurs over extensive areas during mountain building, involving high temperature and pressure over long geological periods.
The Gutenberg discontinuity separates the
A Crust and mantle
B Upper and lower mantle
C Mantle and outer core
D Outer and inner core
The Gutenberg discontinuity marks the boundary between the mantle and the outer core, identified by sudden changes in seismic wave behavior.
Which type of earthquake originates due to collapse of underground cavities
A Tectonic
B Volcanic
C Collapse
D Induced
Collapse earthquakes occur due to sudden failure of underground cavities, often associated with mining areas or limestone regions.
The term ‘Ring of Fire’ refers to
A Volcanic islands near Equator
B Earthquake-prone polar zone
C Circum-Pacific seismic belt
D Mid-Atlantic ridge system
The Ring of Fire is a zone around the Pacific Ocean characterized by frequent earthquakes and volcanoes due to intense plate tectonic activity.
Which movement of tectonic plates leads to strike-slip faults
A Divergent movement
B Convergent movement
C Vertical movement
D Horizontal movement
Strike-slip faults develop when plates move horizontally past each other, producing shear stress and lateral displacement.
Which latitude marks the southern limit of the tropics
A Tropic of Cancer
B Equator
C Tropic of Capricorn
D Antarctic Circle
The Tropic of Capricorn at 23½° south marks the southernmost position of the overhead Sun and defines the boundary of tropical zone.
The chemical composition of the Earth’s core is dominated by
A Silicon and aluminum
B Magnesium and oxygen
C Nickel and iron
D Carbon and hydrogen
The core is composed mainly of nickel and iron, collectively called nife, contributing to high density and magnetic properties.
Which process converts sedimentary rocks back into molten magma
A Lithification
B Metamorphism
C Weathering
D Melting
When sedimentary rocks are subjected to extremely high temperatures deep within Earth, they melt and form magma, continuing the rock cycle.
Which rock type generally lacks stratification
A Sedimentary
B Metamorphic
C Igneous
D Chemical sedimentary
Igneous rocks form from solidified magma and usually lack layers or stratification, unlike sedimentary rocks which form in distinct layers.
Which plate boundary is responsible for creation of island arcs
A Continental divergence
B Oceanic-oceanic convergence
C Continental transform
D Oceanic divergence
When two oceanic plates converge, one subducts beneath the other, forming volcanic island arcs due to rising magma.
Which wave type is most useful in determining Earth’s internal structure
A Love waves
B Surface waves
C P-waves
D Tsunami waves
P-waves can travel through solids, liquids, and gases. Their speed variations help scientists infer composition and boundaries of Earth’s interior.
The concept of Pangaea refers to
A Ancient ocean
B Supercontinent
C Volcanic belt
D Plate boundary
Pangaea was a massive supercontinent that existed during late Paleozoic era before breaking into present-day continents.
Which factor primarily influences the depth of earthquake focus
A Latitude
B Plate type
C Nature of plate interaction
D Distance from equator
The depth of earthquake focus depends on whether plates are converging, diverging, or sliding, with subduction zones producing deeper earthquakes.
Which rock is produced when limestone undergoes contact metamorphism
A Slate
B Quartzite
C Marble
D Gneiss
Limestone transforms into marble under heat during contact metamorphism, recrystallizing calcium carbonate into a harder rock.
The average thickness of the Earth’s crust beneath continents is about
A 5 km
B 15 km
C 35 km
D 70 km
Continental crust averages around 35 kilometers thick, though it may be thicker under mountain ranges and thinner near plate margins.
Which phenomenon indicates the elastic nature of rocks during earthquakes
A Folding
B Faulting
C Elastic rebound
D Isostasy
Elastic rebound theory explains how rocks store energy elastically and release it suddenly during earthquakes, causing seismic waves.
Which rock cycle process involves transportation of weathered material
A Erosion
B Crystallization
C Metamorphism
D Compaction
Erosion involves movement of weathered material by wind, water, ice, or gravity, playing a key role in sedimentary rock formation.
Which plate is considered the largest tectonic plate on Earth
A African Plate
B Eurasian Plate
C Antarctic Plate
D Pacific Plate
The Pacific Plate is the largest tectonic plate, covering a vast area of the Pacific Ocean and associated with high seismic activity.
Which type of volcano has gentle slopes and fluid lava