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Past Questions
The direction of circulation of low pressure in a cyclone in northern hemisphere is
A)
Anticlockwise
B)
Clockwise
C)
Both clockwise and anticlockwise
D)
None of these
The direction of air circulation around a low-pressure system (cyclone) is determined by the interaction between the Pressure Gradient Force (PGF) and the Coriolis Effect.
1. Pressure Gradient Force: Air naturally moves from high pressure toward the center of low pressure.
2. Coriolis Effect: Due to the Earth's rotation, moving air is deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
3. Resultant Flow: In the Northern Hemisphere, as air flows inward toward the low-pressure center, the rightward deflection causes the wind to spiral in an anticlockwise direction.
Conversely, in the Southern Hemisphere, the leftward deflection causes low-pressure systems to circulate clockwise. High-pressure systems (anticyclones) exhibit the opposite behavior (clockwise in the Northern Hemisphere).
The period of retreating south-west monsoon in India is
A)
September to early October
B)
July to early September
C)
August to early September
D)
July to early August
The Indian monsoon system is divided into four main seasons. The South-West Monsoon (the rainy season) typically prevails from June to September. The 'retreating' phase occurs when the sun moves southwards, causing the low-pressure trough over the northern plains of India to weaken and shift south. This transition period, known as the Retreating Monsoon, typically occurs from September to early October (and sometimes extending into November). During this time, the winds begin to shift from the south-west to the north-east, leading to the withdrawal of rainfall from North India and the onset of rainfall in the southeastern coast (Tamil Nadu).
Analysis of other options:
- Option b (July to early September) and Option c (August to early September) describe the peak period of the South-West Monsoon (Advance/Rainy season), not the retreat.
- Option d (July to early August) is the early peak of the South-West Monsoon.
Abyssal plain is found between
A)
Continental slope and continental rise
B)
Continental shelf and continental slope
C)
Below continental rise
D)
Above Continental rise
To determine the correct location of the abyssal plain, we must look at the profile of the ocean floor from the coastline moving seaward:
1. **Continental Shelf**: The shallowest part, extending from the shore to the shelf break.
2. **Continental Slope**: A steep descent from the edge of the shelf down to the deep ocean floor.
3. **Continental Rise**: A gentle slope at the base of the continental slope, formed by the accumulation of sediments (turbidity currents) sliding down from the slope.
4. **Abyssal Plain**: The vast, flat, deep-ocean floor that begins where the continental rise ends.
Therefore, the abyssal plain is located 'below' or 'beyond' the continental rise.
Analysis of options:
- Option (a) is incorrect because the area between the slope and the rise is the transition zone of the rise itself.
- Option (b) is incorrect because the area between the shelf and slope is the shelf break.
- Option (d) is incorrect because the abyssal plain is the deepest part of the basin, not located 'above' the rise.
Vectorization is also known as
A)
Digitization
B)
Scanning
C)
Rasterization
D)
Imaging
Vectorization is the process of converting a raster image (pixels) into a vector graphic (paths, points, and polygons). In the context of GIS (Geographic Information Systems) and Remote Sensing, this process is most commonly referred to as 'Digitization'. Digitization involves tracing the boundaries of features on a map or satellite image to create discrete vector data.
Why other options are incorrect:
- b. Scanning: This is the process of converting a physical hard-copy map into a digital raster image (the opposite of vectorization).
- c. Rasterization: This is the exact inverse of vectorization; it is the process of converting vector data into a raster grid of pixels.
- d. Imaging: This is a broad term referring to the creation of an image (e.g., via a satellite sensor), which results in raster data, not vector data.
Which maps are best to show field boundaries with ownership details
A)
Cadastral maps
B)
Topographical maps
C)
Soil maps
D)
Land utilization maps
Step-by-step reasoning:
1. **Definition of Cadastral Maps**: A cadastral map is a large-scale map that shows the boundaries and ownership of individual parcels of land (plots). These maps are primarily used by governments for taxation, land registration, and legal disputes regarding property boundaries.
2. **Analyzing the Requirement**: The question asks for maps that show 'field boundaries' and 'ownership details'. This is the primary purpose of a cadastral survey.
3. **Evaluating Other Options**:
- **Topographical maps (b)**: These show the physical features of the land (relief, rivers, roads, vegetation) but do not typically detail individual private property ownership or precise legal boundaries.
- **Soil maps (c)**: These are thematic maps showing the distribution of different soil types across a region; they have nothing to do with ownership.
- **Land utilization maps (d)**: These show how land is being used (e.g., agriculture, forest, urban) but do not specify who owns the land or the exact legal boundaries of a plot.
Therefore, Cadastral maps are the only option that satisfies both the boundary and ownership requirements.
Which of the following is a measures of central tendency of mathematical average ?
A)
Geometric mean
B)
Median
C)
Mode
D)
Range
Measures of central tendency are generally divided into two categories: Mathematical Averages and Positional Averages.
1. Mathematical Averages: These are calculated using a mathematical formula involving all the observations in the data set. Examples include the Arithmetic Mean, Geometric Mean, and Harmonic Mean. Since the Geometric Mean is calculated using a specific mathematical formula (the nth root of the product of n numbers), it is a mathematical average.
2. Positional Averages: These are based on the position of the value in an ordered data set. Examples include the Median (the middle value) and the Mode (the most frequent value). Therefore, options (b) Median and (c) Mode are positional averages, not mathematical averages.
3. Range: The Range is a measure of dispersion (variability), not a measure of central tendency. Therefore, option (d) is incorrect.
The term ‘training sites’ is associated with which image classification ?
A)
Supervised
B)
Unsupervised
C)
Both supervised and Unsupervised
D)
None of these
In Remote Sensing, image classification is the process of assigning pixels to specific land-cover classes. There are two primary methods: Supervised and Unsupervised classification.
1. Supervised Classification: In this method, the analyst (user) provides 'training sites' to the software. Training sites are representative areas of known land cover (e.g., a known forest patch or a known water body) within the image. The software analyzes the spectral signatures of these training sites and then assigns all other pixels in the image to the class they most closely resemble. Therefore, training sites are a fundamental requirement for supervised classification.
2. Unsupervised Classification: In this method, the software automatically groups pixels into clusters based on their natural spectral similarities without any prior knowledge of the land cover. The analyst only assigns labels to these clusters after the process is complete. No training sites are used during the classification process itself.
Since training sites are exclusively used to 'teach' the algorithm in supervised classification, option (a) is the correct answer.
The divergent plate boundary is also known as
A)
Subduction zone
B)
Spreading centre
C)
Collision zone
D)
Elastic zone
A divergent plate boundary occurs where two tectonic plates move away from each other. As the plates separate, magma rises from the mantle to fill the gap, cools, and solidifies, creating new oceanic crust. This process is known as seafloor spreading; therefore, these boundaries are referred to as 'spreading centres'. Examples include the Mid-Atlantic Ridge and the East African Rift.
Why other options are incorrect:
- a. Subduction zone: This occurs at convergent boundaries where one plate sinks beneath another.
- c. Collision zone: This occurs at convergent boundaries where two continental plates collide, forming mountain ranges (e.g., the Himalayas).
- d. Elastic zone: This is not a type of plate boundary; elasticity refers to the property of rocks to deform and snap back, which is related to earthquake mechanics (elastic rebound theory), not boundary classification.
Which of the following is an example for diastrophic force?
A)
Orogenesis
B)
Landslides
C)
Soil creep
D)
Mudflow
Diastrophic forces (or diastrophism) are endogenic processes that act slowly over long periods to deform the Earth's crust, creating large-scale structural features. These are divided into epeirogenic (continent-building) and orogenic (mountain-building) movements. Orogenesis refers specifically to the process of mountain building through folding and faulting of the crust, making it a primary example of a diastrophic force. In contrast, landslides (b), soil creep (c), and mudflow (d) are all examples of 'mass wasting' or 'mass movement,' which are exogenic processes driven primarily by gravity and surface conditions rather than internal tectonic forces.
Isochrons are the lines which join points of equal
A)
Dates of humidity
B)
Dates of magnetic stripes
C)
Dates of rainfall
D)
Dates of temperature
In the context of Geomorphology and Plate Tectonics, 'Isochrons' (from the Greek 'iso' meaning equal and 'chronos' meaning time) are lines that connect points of the same age. Specifically, in the study of seafloor spreading, isochrons are used to map the age of the oceanic crust. As magma rises at mid-ocean ridges and solidifies, it records the polarity of the Earth's magnetic field at that time. By identifying these magnetic stripes (magnetic anomalies) on the ocean floor, scientists draw isochron lines to join areas of the crust that were formed at the same time.
Why other options are incorrect:
- Option (a) 'Dates of humidity' and (c) 'Dates of rainfall' are not standard geomorphological or meteorological terms associated with isochrons.
- Option (d) 'Dates of temperature' is incorrect; lines of equal temperature are called 'Isotherms'.
Which layer of the atmosphere is called Convective region?
A)
Stratosphere
B)
Troposphere
C)
Exopsphere
D)
Ionosphere
The troposphere is known as the 'convective region' of the atmosphere because it is the layer where vertical air movement (convection) is most dominant. In this layer, the atmosphere is heated from below by the Earth's surface. Warm air becomes less dense and rises, while cooler air sinks, creating convection currents. This process is responsible for the formation of clouds, precipitation, and almost all weather phenomena.
Why other options are incorrect:
- a. Stratosphere: This layer is characterized by a temperature inversion (temperature increases with altitude), which acts as a 'cap' that inhibits vertical movement, making it very stable and non-convective.
- c. Exosphere: This is the outermost layer where the air is extremely thin and molecules escape into space; it does not support convective weather systems.
- d. Ionosphere: This is a region of the upper atmosphere (overlapping the mesosphere and thermosphere) characterized by ionized particles; it is not a region of convective weather processes.
The material found in the rift valleys is from
A)
Aesthenosphere
B)
Core
C)
Continental crust
D)
Upper crust
A rift valley is a linear-shaped lowland between highlands or mountain ranges created by the action of a geologic rift or fault. This process occurs when the Earth's lithosphere is pulled apart (divergent boundary). The material that forms the walls and the floor of the rift valley consists of the existing rock layers of the continental crust that have been fractured and displaced downward. While magma from the asthenosphere may rise into a rift valley (leading to volcanism), the primary 'material' that constitutes the structure and the bulk of the valley's geological makeup is the continental crust.
- Option (a) Asthenosphere: This is the semi-fluid layer below the lithosphere. While it provides the heat and magma that drive rifting, the valley itself is a feature of the crust.
- Option (b) Core: The core is thousands of kilometers below the surface and does not contribute material to surface rift valleys.
- Option (d) Upper crust: While the upper crust is involved, rift valleys often involve deep faulting that penetrates through a significant portion of the continental crust (including the lower crust) to create the graben structure.
The process of collision of oceanic and continental plates is known as
A)
Divergence
B)
Subduction
C)
Convergence
D)
transformation
Step-by-step reasoning: 1. The question asks for the process involving the 'collision' of two different types of tectonic plates (oceanic and continental). 2. In plate tectonics, when two plates move toward each other and collide, the general process is called 'Convergence'. 3. Specifically, when an oceanic plate meets a continental plate, the denser oceanic plate is forced beneath the lighter continental plate; this specific mechanism within a convergent boundary is called 'Subduction'. 4. However, 'Subduction' is a result/subset of the broader process of 'Convergence'. Between the options provided, 'Convergence' is the overarching term for the collision of plates. 5. Analysis of other options: (a) Divergence occurs when plates move apart; (d) Transformation (Transform boundaries) occurs when plates slide horizontally past each other. Therefore, Convergence is the most accurate term for the collision process.
Volcanic neck is also known as
A)
Plug dome
B)
Diatreme
C)
Parasite cone
D)
Caldera
A volcanic neck (or volcanic plug) is a column of solidified magma that forms within the vent of a volcano. When the surrounding softer volcanic ash and rock erode away over time, the harder, solidified magma remains as a prominent vertical tower or 'plug'. This structure is often referred to as a plug dome.
Why other options are incorrect:
- b. Diatreme: This is a volcanic pipe formed by a gaseous explosion that blasts through the rock, often filled with fragmented rock (breccia), rather than a solid plug of magma.
- c. Parasite cone: Also known as a side vent, this is a smaller cone that forms on the flank of a larger volcano, not the central solidified neck.
- d. Caldera: This is a large, cauldron-like hollow that forms shortly after the emptying of a magma chamber in an explosive eruption, resulting in the collapse of the volcano's summit.
Beach ridges are also known as
A)
Beach cusps
B)
Berms
C)
Barriers
D)
Offshore bars
Beach ridges are linear accumulations of sand and gravel deposited parallel to the shoreline. In geomorphology, when these ridges grow and merge to form a continuous elongated strip of land that separates a lagoon or coastal plain from the open ocean, they are referred to as barrier islands or barrier beaches.
Why other options are incorrect:
- a. Beach cusps: These are crescent-shaped shoreline features formed by wave action, not linear ridges.
- b. Berms: A berm is a specific flat area or 'step' on the upper part of a beach created by the deposition of sediment during high tide; while related to beach ridges, it is a component of the beach profile rather than a synonym for the ridge system.
- d. Offshore bars: These are submerged or partially submerged ridges of sand located parallel to the shore but separated from it by a trough of water, whereas beach ridges are emergent (above sea level) features.
The volcanic cones formed due to accumulation of different layers of volcanic materials are known as
A)
Ant mount
B)
Strato-cones
C)
Plug dome
D)
Craterlets
Step-by-step reasoning: 1. The question asks for the name of volcanic cones formed by the accumulation of different layers of volcanic materials. 2. Stratovolcanoes (or Strato-cones/Composite cones) are characterized by a conical shape built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. This alternating layering occurs because these volcanoes typically have explosive eruptions followed by quieter lava flows. 3. Analyzing other options: (a) 'Ant mount' is not a recognized geomorphological term for a volcanic cone. (c) A 'Plug dome' (or volcanic plug) is the solidified magma that hardens inside the vent of a volcano, rather than a layered cone. (d) 'Craterlets' are small craters, often found within a larger caldera or on the flanks of a volcano, but they are not the layered cones themselves. Therefore, Strato-cones is the correct term.
The average density of the earth’s core is
A)
12g cm-3
B)
11 g cm-3
C)
5.5 g cm-3
D)
2.6 g cm-3
The Earth's interior is stratified based on density. The overall average density of the entire Earth is approximately 5.51 g/cm³. However, the density increases significantly toward the center due to gravitational compression and the composition of materials. The crust has a low density (approx. 2.7–3.0 g/cm³), and the mantle ranges from about 3.4 to 5.6 g/cm³. The core, composed primarily of iron and nickel, is the densest layer. The outer core density ranges from approximately 9.9 to 12.2 g/cm³, and the inner core reaches up to 13 g/cm³. The average density of the core as a whole is generally cited in geomorphology and geology textbooks as approximately 11 g/cm³ to 13 g/cm³. Among the given options, 11 g/cm³ is the most accurate representation of the core's average density.
Breakdown of other options:
- Option (a) 12g cm-3: While close, 11g cm-3 is often used as the standard average for the core in many academic contexts, though 12-13 is found at the center.
- Option (c) 5.5 g cm-3: This is the average density of the entire Earth, not specifically the core.
- Option (d) 2.6 g cm-3: This is representative of the average density of the continental crust.
According to Daly how many layers are present in the interior of the earth ?
A)
3
B)
4
C)
5
D)
2
Reginald Daly, a prominent geologist, proposed a model of the Earth's interior based on chemical composition and physical properties. According to Daly's classification, the Earth is divided into three primary concentric layers: 1. The Sial (Silica and Aluminium), which forms the continental crust; 2. The Sima (Silica and Magnesium), which forms the oceanic crust and the upper mantle; and 3. The Nife (Nickel and Iron), which constitutes the Earth's core. While modern seismology has further subdivided these into the crust, mantle, and core (and further into lithosphere, asthenosphere, etc.), Daly's fundamental model focused on these three chemical layers.
The rift valley of East Africa is an example for
A)
Convergent margin
B)
Divergent margin
C)
Collision zone
D)
Submergence zone
The East African Rift System (EARS) is a classic example of a divergent plate boundary occurring on a continental landmass.
1. **Mechanism**: Divergent margins occur where tectonic plates move away from each other. In the case of East Africa, the African Plate is splitting into two smaller plates: the Nubian Plate (to the west) and the Somalian Plate (to the east).
2. **Process**: As the plates pull apart, the lithosphere thins and stretches, causing the crust to fracture and drop down, creating a 'rift valley' (a graben). If this process continues, the valley will eventually drop below sea level, allowing the ocean to flood in and create a new linear sea (similar to the Red Sea) and eventually a new ocean basin.
**Why other options are incorrect:**
- **a. Convergent margin**: These occur where plates move toward each other, typically resulting in mountain building (e.g., Himalayas) or subduction zones, not rift valleys.
- **c. Collision zone**: This is a specific type of convergent boundary where two continental plates collide. This leads to crustal thickening and uplift, the opposite of the thinning and sinking seen in rift valleys.
- **d. Submergence zone**: While the valley floor sinks, 'submergence' is not a standard tectonic margin classification. Subduction zones (where one plate sinks beneath another) are convergent, not divergent.
The volcanic lava occur along the constructive plate margins is called
A)
Tholeiite
B)
Aa aa lava
C)
Tephra
D)
Phreatic lava
Step-by-step reasoning: 1. Constructive plate margins (also known as divergent boundaries) occur where tectonic plates move apart, such as at Mid-Ocean Ridges (MOR). 2. At these boundaries, decompression melting of the mantle occurs, producing basaltic magma. 3. The specific chemical composition of the basaltic lava found at these mid-ocean ridges is characterized as 'Tholeiitic basalt' (Tholeiite). Tholeiites are sub-alkaline basalts that are typical of oceanic crust and large igneous provinces. 4. Evaluating other options: (b) 'Aa' is a morphological description of lava based on surface texture (blocky/jagged), not a chemical type associated specifically with a plate margin. (c) 'Tephra' refers to all fragmented material ejected during a volcanic eruption (ash, lapilli, bombs), regardless of the plate margin. (d) 'Phreatic' refers to steam-driven explosions caused by magma heating groundwater, which is a process rather than a type of lava associated with constructive margins.
Which of the following is a depositional landform of glacial topography?
A)
Nunatak
B)
Horn
C)
Drumlins
D)
Tarn
To solve this question, we must distinguish between erosional and depositional landforms created by glacial activity:
1. **Drumlins (Option c):** These are elongated, teardrop-shaped hills formed by the deposition of glacial till (unsorted sediment) as a glacier moves over it. Because they are composed of deposited material, they are classified as depositional landforms.
2. **Nunatak (Option a):** A nunatak is an exposed peak of rock projecting through an ice sheet or glacier. It is a remnant of the landscape that was not covered by ice, not a landform created by deposition.
3. **Horn (Option b):** A glacial horn (e.g., the Matterhorn) is a sharp, pyramid-shaped peak formed when several cirques erode the sides of a single mountain. This is a classic erosional landform.
4. **Tarn (Option d):** A tarn is a mountain lake that forms in a cirque (a bowl-shaped depression) after the glacier has melted. The cirque itself is created by glacial erosion (plucking and abrasion), making the tarn a feature of an erosional landform.
Therefore, among the given options, only Drumlins are depositional.
In glacial areas the higher peaks and mounds are surrounded by ice from all sides are called
A)
Tarn
B)
Nunatak
C)
Crag and tail
D)
Moraines
A Nunatak is an isolated peak of rock that projects above the surface of an ice sheet or glacier. The term comes from the Greenlandic word 'nunataq'. These peaks are surrounded by ice on all sides and are significant in geomorphology and biology as they often serve as refugia for alpine plants and animals during glacial periods.
Why other options are incorrect:
- a. Tarn: A tarn is a mountain lake or pool formed in a cirque excavated by a glacier.
- c. Crag and tail: This is a glacial landform consisting of a steep rock face (the crag) and a tapering ridge of softer rock or debris (the tail) formed by the erosive action of a glacier flowing past a resistant rock outcrop.
- d. Moraines: Moraines are accumulations of unconsolidated glacial debris (till) deposited by a glacier, rather than the peaks themselves.
Which one of following is a depositional landform?
A)
Structural bench
B)
Natural levee
C)
River terrace
D)
River meander
To identify the depositional landform, we must analyze the geomorphic processes (erosion vs. deposition) associated with each option:
1. **Natural levee (Option b):** This is a classic depositional landform. During a river flood, water overflows the banks. As the velocity of the water decreases abruptly upon leaving the main channel, the coarsest sediment is deposited immediately along the edges of the bank, building up raised ridges known as natural levees.
2. **Structural bench (Option a):** This is primarily a result of differential erosion. It occurs when a river cuts through alternating layers of hard and soft rock, leaving the harder rock as a protruding 'bench'.
3. **River terrace (Option c):** While terraces contain deposits, they are fundamentally considered erosional remnants of former floodplains. They are formed when a river incises (cuts down) into its own previous floodplain due to rejuvenation or a drop in base level.
4. **River meander (Option d):** A meander is a complex feature involving both erosion and deposition. However, the 'meander' as a whole is a pattern of the river's course. The outer bank (cut bank) is formed by erosion, while the inner bank (point bar) is formed by deposition. Because the overall process of meandering is driven by lateral erosion, it is not classified strictly as a 'depositional landform' in the same way a levee is.
Therefore, the Natural Levee is the only option that is exclusively a product of deposition.
The other name for the zone of collision of convergent plates
A)
Benioff zone
B)
Obduction zone
C)
Shear zone
D)
Accretion zone
In geomorphology and plate tectonics, a convergent boundary occurs where two plates collide. When an oceanic plate subducts beneath another plate, it creates a dipping seismic zone where earthquakes occur at increasing depths. This zone of collision and subduction is known as the Benioff zone (or Wadati-Benioff zone).
Why other options are incorrect:
- b. Obduction zone: Obduction is the rare process where oceanic crust is pushed onto continental crust rather than subducting beneath it; it is not the general name for the collision zone.
- c. Shear zone: A shear zone is associated with transform boundaries (plates sliding past each other) or ductile deformation in the crust, not specifically the collision of convergent plates.
- d. Accretion zone: While accretion occurs at convergent boundaries (where sediments are scraped off the subducting plate), the 'accretionary wedge' is a feature of the zone, but the overall seismic zone of collision/subduction is defined as the Benioff zone.
Whose slope model reveals that the mechanism of surface process is affected and controlled by the properties of forms?
A)
W.M.Davis
B)
A.W.Wood
C)
W.Penck
D)
R.A.Savigear
The question refers to the concept of 'form-controlled' surface processes. R.A. Savigear developed a slope model that emphasizes the feedback loop between the morphology of the slope (the form) and the processes acting upon it. Specifically, Savigear's work suggests that the geometry and properties of the landform itself influence the mechanism of the surface processes (such as soil creep or wash), which in turn further modify the form.
Comparing the options:
- W.M. Davis (a) is known for the 'Cycle of Erosion' (youth, maturity, old age), focusing on time and stage rather than the specific feedback of form on process.
- W. Penck (c) focused on the relationship between the rate of uplift and the rate of degradation (slope replacement), emphasizing tectonic control.
- A.W. Wood (b) is not a primary figure associated with a foundational slope model of this specific nature in standard geomorphology textbooks.
- R.A. Savigear (d) specifically addressed the interaction where the properties of the form control the surface processes.