Test: Geography- 1 - UPSC MCQ

 The Earth is made up of several concentric layers with one inside another. The uppermost layer over the Earth's surface is called the crust. It is the thinnest of all the layers. It is about 35 km on the continental masses and only 5 km on the ocean floors. The Earth's crust is made up of various types of rocks. Any natural mass of mineral matter that makes up the Earth's crust is called a rock. Rocks can be of different colour, sizes and textures. There are three major types of rocks: igneous rocks, sedimentary rocks and metamorphic rocks. When the molten magma cools, it becomes solid. Rocks thus formed are called igneous rocks. They are also called primary rocks. The most abundant rocks in the crust are igneous rocks. So, Statement 1 is correct.

The continental crust is less dense than all the layers of the Earth's interior. Its density is 2.7g/cm³, whereas the density of the oceanic crust is 3.0 g/cm³, and that of the Earth's mantle is 3.3 g/cm³. The main mineral composition of continental crust is Silica and Aluminium. This layer is also commonly known as the Sial layer. The oceanic crust is made of denser rock made of basalt and is dominated by Silica (Si) and Magnesium (SIMA). When an oceanic crust converges with a continental crust, it always subducts below the continental crust as the oceanic crust is more dense and heavy, and it melts and gets subsumed into the mantle after subduction. So, Statement 2 is not correct.

The thickness of oceanic crust ranges between 5 and 7 kilometers which are substantially shallower than continental crust. The continental crust covers an average distance of 35-40 km; in some places, it extends upto 70 km. So, Statement 3 is correct.

The 'Goldilocks Zone,' or habitable zone, is the distance range with the right temperatures for water to remain liquid. The distance Earth orbits the Sun is just right for water to remain a liquid. This distance from the Sun is called the habitable or Goldilocks zone. So, Statement 1 is correct.

Venus and Mars are also considered to be a part of the goldilocks zones in our Solar system along with Earth, but they aren't currently habitable. Today, Mars is a frigid desert. Many dried-up riverbeds, deltas, lake basins, and inland seas make it clear that Mars once had much water on its surface. Research suggests that most of Mars’s water escaped into space as its atmosphere was stripped away by the sun’s radiation. Today, aside from a possible series of briny, underground lakes and aquifers, most of Mars’s water is locked up in the polar caps or ice buried below the surface. Venus may have had a shallow liquid-water ocean and habitable surface temperatures for up to 2 billion years of its early history, according to computer modeling of the planet’s ancient climate by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. Venus is closer to the sun than Earth and receives far more sunlight. As a result, the planet’s early ocean evaporated, water-vapor molecules were broken apart by ultraviolet radiation, and hydrogen escaped to space. With no water left on the surface, carbon dioxide built up in the atmosphere, leading to a so- called runaway greenhouse effect that created present conditions. So, Statement 2 is correct. 

The following biodiversity heritage sites, which are unique, ecologically fragile ecosystems, are located in Karnataka, - Nallur Tamarind Grove - It is popularly believed to be a relic of the Chola Dynasty that ruled nearly 800 years ago. - Hogrekan - The area has unique Shola vegetation and grassland. Its dry deciduous vegetation is linked with Bababudanagiri and Kemmangundi, adjoining Bhadra Wildlife Sanctuary and Yemmedode Tiger Reserve and serving as a "Wildlife Corridor" between Kudremukha and Bhadra Wildlife Sanctuary. - University of Agricultural Sciences, GKVK Campus, Bengaluru – It is considered one of the greenest areas in Bengaluru. - Ambaraguda is a revenue land between Sharavathi Wild Life Sanctuary and Someshwara Wildlife Sanctuary. It has Shola vegetation which is primitive vegetation in the Western Ghats and grasslands. - Antaragange Betta in Kolar is a unique and perennial water source flowing throughout the year. - Aadi Narayana Swamy Betta in Chickballapur - had many dry-belt species protected by locals. - Mahima Ranga Betta in Nelamangala, Bengaluru – It is a prominent lung space surviving in Bengaluru. - The Urumbi area on the Kumaradhara river basin in Dakshina Kannada has a fragile environmental system and is located on the banks of the river Kumaradhara. So, Option (b) is correct.

• Soil erosion is essentially aggravated by faulty practices. Lands with a slope gradient of 15–25 percent should not be used for cultivation. If at all the land is to be used for agriculture, terraces should carefully be made.
• Efforts should be made to prevent gully erosion and control their formation. Finger gullies can be eliminated by terracing. In bigger gullies, the erosive velocity of water may be reduced by constructing a series of check dams. Special attention should be paid to control headward extension of gullies. This can be done by gully plugging, terracing, or by planting cover vegetation
  • Terracing is a soil conservation practice applied to prevent rainfall runoff on sloping land from accumulating and causing serious erosion. Terraces consist of ridges and channels constructed across- the-slope.
• In arid and semi-arid areas, efforts should be made to protect cultivable lands from encroachment by sand dunes through the development of shelter belts of trees and agroforestry. Lands not suitable for cultivation should be converted into pastures for grazing. •
• Hence option (a) is the correct answer.

• Tropical Evergreen forests are found in the western slope of the Western Ghats, hills of the northeastern region and the Andaman and Nicobar Islands.
• They are found in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22 degree C.
• The Western Ghats in India provide favorable conditions for orographic rainfall. The warm and moist air from the Arabian sea is blocked by the Western Ghats and gets lifted over mountain ranges. As the air rises and cools, orographic clouds are formed resulting in precipitation.
  • Due to orographic rainfall, the western side of the western ghats receives heavy rainfall, more than 250cm rainfall per year. and aids in growth of Tropical evergreen forests in India.
• These forests can be extremely dense and multi-layered, with a few areas being so dense that the forest floor hardly receives any sunlight due to the engulfing leaves and large trees.
• The main vegetation found in these forests is Ebony, Mahogany, and Rosewood.
• The tropical evergreen forests are known as lungs of the Earth because of huge greenery and the amount of oxygen they produce. The plants usually draw carbon dioxide and produce oxygen, hence are called as the lungs of the Earth.
• Hence, option (a) is the correct answer. 

• Many local winds, some hot, others cold are common around the Mediterranean Sea. The causes are many and varied. The topography of the region with the high Alps in the north, the Sahara desert in the south, continental interiors in the east and the open Atlantic on the west give rise to great differences in temperature, pressure and precipitation.
• The passing cyclones from the Atlantic, the anticyclones from the north, and the cold air masses from the continental interiors are often interrupted or channelled by relief features, resulting in the birth of local winds around the Mediterranean. These winds varying in strength, direction and duration affect the lives, crops and activities of the people there.
• Sirocco.
  • This is a hot dry dusty wind which originates in the Sahara Desert . Though it may occur at any time of the year, it is most frequent in spring and normally lasts for only a few days. The Sirocco blows outwards in a southerly direction from the desert interiors into the cooler Mediterranean Sea. It is usually associated with depressions from the Atlantic passing from the coast eastwards inland.
• Mistral.
  • Mistral is a cold wind from the north of Mediterranean sea , rushing down the Rhone valley in violent gusts between 40 and 80 miles per hour. The velocity of the Mistral is intensified by the funnelling effect in the valley between the Alps and the Central Massif, and in extreme cases trains may be derailed and trees uprooted.
• A similar type of cold north-easterly wind experienced along the Adriatic coast is called the Bora. Like the Mistral, it is caused by a difference in pressure between continental Europe and the Mediterranean. This usually occurs in winter, when the atmospheric pressure over continental Europe is higher than that of the Mediterranean Sea.
• In West Africa, the North- East Trades blow offshore from the Sahara Desert and reach the Guinea coast as a dry, dust -laden wind, called locally the Harmattan meaning The doctor’.
  • It is so dry that its relative humidity seldom exceeds 30 per cent. The doctor’ provides a welcome relief from the damp air of the Guinea lands by increasing the rate of evaporation with resultant cooling effects, but it is such a dry dusty wind that , besides ruining the crops, it also stirs up a thick dusty haze and impedes inland river navigation.
• Hence option (b) is the correct answer. 

• Alluvial soils are widespread in the northern plains and the river valleys. These soils cover about 40 percent of the total area of the country. They are depositional soils, transported and deposited by rivers and streams. Hence statement 1 is correct.
• The alluvial soils vary in nature from sandy loam to clay. They are generally rich in potash but poor in phosphorous. Hence statement 2 is not correct.
• In the Upper and Middle Ganga plain, two different types of alluvial soils have developed, viz. Khadar and Bhangar. Khadar is the new alluvium and is deposited by floods annually, which enriches the soil by depositing fine silts.
• Bhangar represents a system of older alluvium, deposited away from the flood plains. Both the Khadar and Bhangar soils contain calcareous concretions (Kankars). These soils are more loamy and clayey in the lower and middle Ganga plain and the Brahmaputra valley.

With the increase in development, the demand for minor minerals such as Sand and gravel has crossed 60 million metric tons in India. This also makes it the second largest extractive industry on the planet, after water. So, Statement 1 is correct.

The regulatory and administrative jurisdiction of minor minerals falls exclusively under the purview of state governments, unlike those of major minerals. These include the powers to frame rules, prescribe rates of royalty, contribution to the District Mineral Foundation, the procedure for grant of mineral concessions etc., So, Statement 2 is not correct.

The list of 31 minerals to be notified as minor minerals include Agate, Ball Clay, Barytes, Calcareous Sand, Calcite, Chalk, China Clay, Clay (Others), Corundum, Diaspore, Dolomite, Dunite/pyroxenite, Felsite, Felspar, Fireclay, Fuschite Quartzite, Gypsum, Jasper, Kaolin, Laterite, Limekankar, Mica, Ochre, Pyrophyllite, Quartz, Quartzite, Sand (Others), Shale, Silica Sand, Slate, and Steatite/Talc/Soapstone. In addition to the minor minerals specified in Section 3(e) of the MMDR Act, the Central Government has declared the following minerals as minor minerals: - Boulder, - shingle, - chalcedony pebbles used for ball mill purposes only, - lime shell, kankar and limestone used in kilns for the manufacture of lime used as a building material, - murrum, - brick-earth, - fuller's earth, - bentonite, - road metal, - reh-Matti, - slate and shale when used for building materials, - marble, - the stone used for making household utensils, - quartzite and sandstone when used for purposes of building or for making road metal and household utensils, - saltpeter and - Ordinary earth (used for filling or leveling purposes in construction or embankments, roads, railways, and buildings). So, Statement 3 is correct.

Panchet dam is built across the Damodar River in Dhanbad District’s Panchet area in Jharkhand. Inaugurated in 1959, Panchet dam is the fourth of the 4 multi-purpose dams that fall under the first phase of Damodar Valley Corporation. The Panchet dam was commissioned as a multipurpose river valley project under the authority of Damodar Valley Corporation (DVC) across the river Damodar at the border of West Bengal and Jharkhand states of India in 1959. So, Pair 1 is correct.

World’s largest masonry dam protected with 26 gates measuring 124.663m in height, Nagarjunasagar Dam is located in the Nalgonda District of Telangana. It is built across the river Krishna and not the river Tungabhadra. The dam has a storage capacity of nearly 11,472 million cubic meters with an irrigation capacity for 9.81 lac acres of land. The dam measures150m tall and 16 km in length while also being a major tourist attraction. In fact, it is among the first irrigation projects started by the Indian Government as an element of the Green Revolution. So, Pair 2 is not correct.

Reaching a staggering height of 260 meters, the imposing Tehri Dam is one of the tallest dams in the world and the tallest dam in India, built on the Bhagirati river, which merges with the Alaknanda river to form River Ganga at Devprayag. An engineering marvel in itself, Tehri Dam not only provides more than 1,000 MW of hydroelectricity but also is a popular tourist attraction in Uttarakhand. The dam reservoir, also known as Tehri Lake, is usually flocked with tourists interested in boating and is slowly becoming a prominent hub for adventure tourism in Uttarakhand. So, Pair 3 is correct.

Hirakud Dam is one of the longest dams in the world, located at a distance of 15km from the main city of Sambalpur in Odisha. It is the world’s longest earthen Dam, about 16 miles and around 26 km in length. Built on the River Mahanadi (not Tapi river) at the cost of Rs.1000 million, the Hirakud Dam project is one of its kind in the entire country. After India’s independence, it is said to be one of the first major multi-use river valley projects. From horizon to horizon, the reservoir forms the largest artificial lake in Asia, with an area of 746 sq.Kms. and shoreline over 640 kms. A 21 Kilometres drive on the dyke offers a unique experience of calm serenity and majesty of nature. So, Pair 4 is not correct. 

The Ravi is an important tributary of the Indus river. It rises west of the Rohtang pass in the Kullu hills of Himachal Pradesh and flows through the Chamba valley of the state. Before entering Pakistan and joining the Chenab near Sarai Sindhu, it drains the area lying between the southeastern part of the Pir Panjal and the Dhauladhar ranges. So, Option (a) is not correct.

Mahananda is a typical river system consisting of two different streams; one arising from the mountainous region of the Himalayas in Nepal traverses through the Indian state of Bihar and outfalls in the Ganga on the left opposite Rajmahal in Bihar and is locally named as river Fulahar. The other stream, also named Mahananda, rises downhill in Darjeeling in West Bengal and traverses a distance of about 400 kms. So, Option (b) is correct.

The Ramganga river is a comparatively small river rising in the Garhwal hills near Gairsain in the Chamoli district of Uttarakhand. It changes its course to the southwest direction after crossing the Shiwalik and enters into the plains of Uttar Pradesh near Najibabad. Finally, it joins the Ganga near Kannauj. So, Option (c) is correct.

The Chambal river rises near Mhow in the Malwa plateau of Madhya Pradesh and flows northward through a gorge upwards of Kota in Rajasthan, where the Gandhisagar dam has been constructed. From Kota, it traverses to Bundi, Sawai Madhopur and Dholpur and finally joins the Yamuna. The Chambal is famous for its badland topography called the Chambal ravines. So, Option (d) is correct.

According to the International Astronomical Union in 2006, a planet must do three things to be defined as a planet.

• It must orbit a star (in our cosmic neighborhood, the Sun). So, Statement 1 is correct.
• It must be big enough to have enough gravity to force it into a spherical shape. So, Statement 2 is correct.
• It must be big enough that its gravity cleared away any other objects of similar size near its orbit around the Sun. So, Statement 3 is correct.
• Every planet, including the earth, drifts away from its parent star so it is not mandatory that a planet should not move away from the star. So, Option (c) is correct. 

The eccentricity of the Earth changes over time due to the gravitational fields of neighboring planets – Jupiter and Saturn. Over time, the pull of gravity from our solar system's two largest gas giant planets, Jupiter and Saturn, causes the shape of Earth's orbit to vary from nearly circular to slightly elliptical. So, Statement 1 is correct.

The increase in the tilt of the Earth’s axis can lead to more extreme seasons on the earth. The greater Earth's axial tilt angle, the more extreme the seasons will become. Each hemisphere of the earth receives more solar radiation during summer when it is tilted toward the Sun and less during winter when it is tilted away. So, Statement 2 is correct.

• Gerosoppa Falls, also known as Jog Falls, is located in the Shimoga district of Karnataka. It is one of the highest waterfalls in India, with a height of 253 metres (829 feet). It is a segmented waterfall that, depending on rain and season, becomes a plunge waterfall.
• The waterfall is formed by the Sharavati River, which originates in the Western Ghats. It is an important river in Karnataka, flowing towards the west. It flows through the dense forests of the Western Ghats and drops down the rocky cliffs at Jog Falls. The water plunges into a deep green valley and creates a spectacular view. Hence option (b) is the correct answer.

• During the southwest monsoon period after having rained for a few days, if rain fails to occur for one or more weeks, it is known as a break in the monsoon. These dry spells are quite common during the rainy season. These breaks in the different regions are due to different reasons:
  • In northern India, rains are likely to fail if the rain-bearing storms are not very frequent along the monsoon trough or the ITCZ over this region.
  • Over the west coast, the dry spells are associated with days when winds blow parallel to the coast.
• Hence option (a) is the correct answer. 

• The summer months are a period of excessive heat and falling air pressure in the northern half of the country. Because of the heating of the subcontinent, the ITCZ moves northwards occupying a position centered at 25°N in July.
• In the heart of the ITCZ in the northwest, the dry and hot winds known as ‘Loo’, blow in the afternoon, and very often, they continue to well into midnight. Dust storms in the evening are very common during May in Punjab, Haryana, Eastern Rajasthan, and Uttar Pradesh.
• Towards the end of summer, there are pre-monsoon showers which are common phenomena in Kerala and coastal areas of Karnataka. Locally, they are known as mango showers since they help in the early ripening of mangoes. These are called mango showers.
• Blossom showers help coffee flowers blossom in Kerala and nearby areas.
• Norwesters are dreaded evening thunderstorms in Bengal and Assam. Their notorious nature can be understood from the local nomenclature of ‘Kalbaisakhi’, a calamity of the month of Baisakh. These showers are useful for tea, jute, and rice cultivation. In Assam, these storms are known as “Bardoli Chheerha”. Hence, option (c) is the correct answer. 

• As the summer sets in and the sun shift northwards, the wind circulation over the subcontinent undergoes a complete reversal at both, the lower as well as the upper levels. By the middle of July, the low-pressure belt nearer the surface, (termed as Inter Tropical Convergence Zone (ITCZ), shifts northwards, roughly parallel to the Himalayas between 20° N and 25° N. Hence statement 1 is correct.
• By this time, the westerly jet stream withdraws from the Indian region. In fact, meteorologists have found an interrelationship between the northward shift of the equatorial trough (ITCZ) and the withdrawal of the westerly jet stream from over the North Indian Plain. Hence statement 2 is not correct.
• At the upper level, an easterly jet stream flows over the southern part of the Peninsula in June and has a maximum speed of 90 km per hour. In August, it is confined to 15°N latitude, and in September up to 22° N latitude. The easterlies normally do not extend to the north of 30° N latitude in the upper atmosphere. Hence statement 3 is not correct. 

There is a large gap between the orbits of Mars and Jupiter. This gap is occupied by a large number of small rocky objects that revolve around the Sun. These are called asteroids. Asteroids can only be seen through large telescopes. Asteroids are minor planets that cannot be classified as a planet or a comet. These are generally in the direct orbit around the Sun, also known as the inner solar system. So, Pair (1) is correct.

A meteor is usually a small object that occasionally enters the Earth's atmosphere. At that time, it has a very high speed. The friction due to the atmosphere heats it up. It glows and evaporates quickly. That is why the bright steak lasts for a very short time. So, Pair (2) is correct.

Some meteors are large, so they can reach the Earth before they evaporate completely. The body that reaches the Earth is called a meteorite. Meteorites help scientists investigate the nature of the material from which the solar system was formed. So, Pair (3) is correct.

Meteoroids are lumps of rock or iron that orbit the Sun, just as planets, asteroids, and comets do. Meteoroids, especially tiny particles called micrometeoroids, are extremely common throughout the solar system. They orbit the Sun among the rocky inner planets and the gas giants that make up the outer planets. Thus Meteoroids are not the body made mostly of ice and dust; it is Comet. Comets are icy bodies of frozen gases, rocks and dust left over from the solar system's formation about 4.6 billion years ago. They revolve around the Sun in highly elliptical orbits. However, their period of revolution around the Sun is usually very long. A Comet generally appears as a bright head with a long tail. The length of the tail grows in size as it approaches the Sun. The tail of a comet is always directed away from the Sun. So, Pair (4) is not correct.

Statement 1 is not correct and 2 is correct.

• The Island is disputed between Japan and Russia.
• he Kuril Islands are a volcanic archipelago administered as part of Sakhalin Oblast in the Russian Far East.
• The Islands stretch approximately 1,300 km northeast from Hokkaido in Japan to Kamchatka Peninsula in Russia, separating the Sea of Okhotsk from the Pacific Ocean. 

• As the monsoon winds approach the Indian subcontinent, their southwesterly direction is modified by the relief and thermal low pressure over northwest India. The monsoon approaches the landmass in two branches: the Arabian Sea branch and the Bay of Bengal branch.
•  The monsoon winds originating over the Arabian Sea splits into three branches.
  • Its one branch is obstructed by the Western Ghats. They bring heavy rainfall in the windward side of the Sahyadris and western coastal plains.
  • Another branch of the Arabian sea monsoon strikes the coast north of Mumbai. Moving along the Narmada and Tapi river valleys, these winds cause rainfall in extensive areas of central India.
  • A third branch of this monsoon wind strikes the Saurashtra Peninsula and the Kachchh. It then passes over west Rajasthan and along the Aravalis, causing only a scanty rainfall. In Punjab and Haryana, it too joins the Bay of Bengal branch. These two branches, reinforced by each other, cause rains in the western Himalayas. Hence, statement 1 is correct.
• The Bay of Bengal branch strikes the coast of Myanmar and part of southeast Bangladesh. But the Arakan Hills along the coast of Myanmar deflect a big portion of this branch toward the Indian subcontinent. The monsoon, therefore, enters West Bengal and Bangladesh from the south and southeast instead of from the south-westerly direction. Hence, statement 2 is correct. 

• Karewas are the thick deposits of glacial clay and other materials embedded with moraines. The Kashmir Himalayas are also famous for Karewa formations, which are useful for the cultivation of Zafran, a local variety of saffron. Hence pair 1 is correctly matched.
• The extension of the Peninsular plateau can be seen as far as Jaisalmer in the West, where it has been covered by longitudinal sand ridges and crescent-shaped sand dunes called barchans. To the northwest of the Aravali hills lies the Great Indian desert. It is a land of undulating topography dotted with longitudinal dunes and barchans. This region receives low rainfall below 150 mm per year; hence, it has an arid climate with low vegetation cover. It is because of these characteristic features that this is also known as Marusthali. Hence pair 2 is not correctly matched.
• Dehradun is the largest of all the duns with an approximate length of 35-45 km and a width of 22-25 km. In the Great Himalayan range, the valleys are mostly inhabited by the Bhotias. These are nomadic groups who migrate to ‘Bugyals’ (the summer grasslands in the higher reaches) during the summer months and return to the valleys during winter. The famous ‘Valley of flowers’ is also situated in this Region. Hence pair 3 is not correctly matched.

• Ocean currents are like river flow in oceans. They represent a regular volume of water in a definite path and direction.
• The ocean currents may be classified based on their depth as surface currents and deep water currents :
  • surface currents constitute about 10 per cent of all the water in the ocean, these waters are the upper 400 m of the ocean
  • deep water currents make up the other 90 per cent of the ocean water.
• These waters move around the ocean basins due to variations in the density and gravity. Deep waters sink into the deep ocean basins at high latitudes, where the temperatures are cold enough to cause the density to increase.
• Ocean currents can also be classified based on temperature: as cold currents and warm currents: o cold currents bring cold water into warm water areas. These currents are usually found on the west coast of the continents in the low and middle latitudes (true in both hemispheres) and on the east coast in the higher latitudes in the Northern Hemisphere o warm currents bring warm water into cold water areas and are usually observed on the east coast of continents in the low and middle latitudes (true in both hemispheres). In the northern hemisphere they are found on the west coasts of continents in high latitudes.
• The Kuroshio Current, also known as the Black or Japan Current or the Black Stream, is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. • Hence option (b) is the correct answer. 

• Siwalik Range, also called Siwalik Hills or Outer Himalayas, Siwalik also spelled Shiwalik, is the sub- Himalayan range of the northern Indian subcontinent. It extends west-northwestward for more than 1,000 miles (1,600 km) from the Tista River in Sikkim state, northeastern India, through Nepal, across northwestern India, and into northern Pakistan. Though only 10 miles (16 km) wide in places, the range has an average elevation of 3,000 to 4,000 feet (900 to 1,200 meters). It rises abruptly from the plain of the Indus and Ganges (Ganga) rivers (south) and parallels the main range of the Himalayas (north), from which it is separated by valleys. The Siwaliks are sometimes considered to include the southern foothills of the Assam Himalayas, which extend eastward for 400 miles (640 km) across southern Bhutan to the bend of the Brahmaputra River. The range proper, to which the name Siwalik (from Sanskrit, meaning “Belonging to [the God] Shiva”) was formerly restricted, is the 200 miles (320 km) of foothills in India extending from the Ganges River at Haridwar, Uttarakhand state, northwestward to the Beas River.
• Vindhya Range is a broken range of hills forming the southern escarpment of the central upland of India. From Gujarat state on the west, it extends about 675 miles (1,086 km) across Madhya Pradesh state to abut on the Ganges (Ganga) River valley near Varanasi, Uttar Pradesh. The mountains form the southern edge of the Malwa Plateau and then divide into two branches: the Kaimur Range, running north of the Son River into western Bihar state, and the southern branch, running between the upper reaches of the Son and Narmada rivers to meet the Satpura Range in the Maikala Range (or Amarkantak Plateau).
• The Satpura Range is formed by a series of scarped plateaus on the south, generally at an elevation varying between 600-900 m above the mean sea level. This forms the northernmost boundary of the Deccan plateau. It is a classic example of the relict mountains which are highly denuded and form discontinuous ranges. • Hence option (a) is the correct answer. 

Earth's geomagnetic field originates in the fluid outer core. Like boiling water on a stove, convective forces (which move heat from one place to another, usually through air or water) constantly churn the molten metals, which also swirl in whirlpools driven by Earth's rotation. As this roiling mass of metal moves around, it generates electrical currents hundreds of miles wide and flowing at thousands of miles per hour as Earth rotates. This mechanism, which is responsible for maintaining Earth's magnetic field, is known as the geodynamo.

Cooling of the Earth's core leads to stopping the convection mechanism within the Earth and also leads to disappear the magnetic shield around the planet, which protects Earth from cosmic radiation. When the Earth has cooled completely, the movement in the mantle will also stop eventually. Then, the plates on the surface will no longer move, and Volcanoes will no longer erupt; the continents will stop drifting, clashing, and causing earthquakes. The magnetic field will disappear, and the planet will become similar to Mars. So, Statements 1, 2 and 3 are correct.

Soil erosion is the displacement of the upper layer of soil (called topsoil). It is a naturally occurring process that affects all landforms. However, certain human activities greatly enhance this process and contribute to significant soil loss. The intensity of soil erosion has also increased due to increased landslides, floods and drought. Soil erosion decreases soil fertility, which can negatively affect crop yields. It also sends soil-laden water downstream, which can create heavy layers of sediment that prevent streams and rivers from flowing smoothly and can eventually lead to flooding. The fertile soil on the top most surface of the dry agricultural land is easily blown away by the wind, which causes soil erosion. So, scarcity of water during drought increases soil erosion. So, Statement 1 is correct.

The raindrops dispersed the soil and washed away into the nearby streams and rivers. Regions with very heavy and frequent rainfall face a large amount of soil loss. When topsoil has eroded, the loss of organic matter can alter the soil's physical properties, especially soil density. Higher clay content at the surface can reduce infiltration of topsoil reducing soil recharge, thus reducing water availability to the plants. The flowing water during floods also erodes a lot of soil by creating potholes, rock-cut basins, etc. Thus, erosion decreases the water holding capacity of the rivers. So, Statement 2 is not correct.

Groundwater erosion is the process by which groundwater erodes part of the bedrock as it passes through. This is primarily due to carbonic acid in the groundwater, which forms when rainwater picks up carbon dioxide in the atmosphere as it falls. The soil erosion mechanisms affect how much water the soil can hold, how rapidly water flows over the soil and its movement below the surface. Soil erosion adversely hinders the growth of plants, agricultural yields, quality of water, and recreation. So, Statement 3 is correct.

Soil erosion reduces the agricultural value of lands via physicochemical degradations. Soil nutrient loss through runoff and sediment is a major driver for soil fertility decline. The eroded sediments or soil are highly concentrated with crop nutrients, which are washed away from farmlands. Some conditions under which erosion can help distribute nutrients across a given area of land. The first condition under which this can occur is a condition of uneven soil nutrient distribution. In such a scenario, nutrients in the form of compost, mulch, or chemical fertilizer; are concentrated heavily in a defined area of land, while the concentration may be very low (relatively) in adjacent areas. A condition like this is unfavorable to the health of the soil and the optimal functioning of the entire ecosystem. Erosion can resolve the problem of uneven nutrient distribution when it occurs mildly or in a cyclic fashion. So, Statement 4 is correct.

Statement 1 is correct: One terrestrial mile (1609 meters) is shorter than one nautical mile (1852 meters).
Statement 2 is not correct: The Harmattan is a seasonal wind in West Africa, occurring from the end of November to the middle of March. It is characterized by dry, dusty northeasterly trade winds that blow from the Sahara Desert over West Africa into the Gulf of Guinea.

Statement 3 is not correct: The Iberian Peninsula includes Portugal and Spain, but it does not include Andorra and Gibraltar.

 Upper, middle and lower are the three courses into which a river valley is divided. Young rivers ( (A) denotes the below picture for the formation of the Young river) close to their source tend to be fast-flowing, high-energy environments with rapid downward and headward erosion, despite the hardness of the rock over which they may flow. The land features carved by a river in its upper course are as follows:

• Gorges,
• Canyons,
• V' shaped valleys,
• Rapids,
• Cataracts, and
• Waterfalls A gorge is a narrow valley with steep, rocky walls between hills or mountains.

The term comes from the French word gorge, which means throat or neck. So, Pair 1 is correct.

Mature rivers or Middle ( (B) denotes the above picture for mature river formation ) are lower-energy systems. Erosion takes place outside bends, creating looping meanders in the soft alluvium of the river plain. Deposition occurs on the inside of the bends and the river bed. Some of the land features formed by a river in its middle course are alluvial fans and meanders. A meander is a bend in the course of a river channel. A meander is formed in the middle course of a river; when the river leaves the mountains, it encounters a sudden slope break and slows down. The plains are broad and gentle. So the river has more time to amble away down to the sea. So, Pair 2 is correct.

Oxbow lakes are formed when the neck of a looping meander is broken through, usually during times of flood. They are U-shaped or curved bends in a river that are cut off from the main river flow, forming a lake. In the lower course of the river, meanders become much more pronounced. The outer or concave bank is so rapidly eroded that the meander becomes almost a complete circle. A time comes when the river cuts through the narrow neck of the loop. The meander, now cut off from the mainstream, takes the form of an oxbow lake. In the lower course or the stage of old age, the land features produced by the river are meanders, flood plains, braided steam, oxbow lakes, deltas and estuaries. So, Pair 3 is correct.

Statement 1 is correct: Crossing through ten countries and draining some 817,000 km² and the territory of 18 countries, the Danube is the most international river in the world.

• Flowing from Germany’s Black Forest to the Danube Delta in Romania and Ukraine and the Black Sea, the Danube is Europe’s only major river which flows west to east, from Central to Eastern Europe Statement 2 is not correct: The Danube is the longest river of the European Union and Europe’s second-longest after the Volga.
• The European Commission now recognizes the Danube as the “single most important non oceanic body of water in Europe” and a “future central axis for the European Union”.
• Statement 3 is correct: Major tributaries of the Danube include the Tisza, Drava, Sava, Inn, and Prut rivers. 

Both the statements are incorrect.

• Suriname is a small country on the northern coast of South America
• Suriname is bordered by the Atlantic Ocean to the north, by French Guiana to the east, by Brazil to the south, and by Guyana to the west.
• Capital: Paramaribo 

• A climatic region has a homogeneous climatic condition which is the result of a combination of factors. Temperature and rainfall are two important elements that are considered to be decisive in all the schemes of climatic classification. The classification of climate, however, is a complex exercise. There are different schemes of classification of climate.
• Koeppen based his scheme of Climatic classification on monthly values of temperature and precipitation. He identified five major climatic types, namely:
  • Tropical climates, where the mean monthly temperature throughout the year is over 18°C.
  • (Dry climates, where precipitation is very low in comparison to temperature, and hence, dry. If dryness is less, it is semiarid (S); if it is more, the climate is arid(W).
  • Warm temperate climates, where the mean temperature of the coldest month is between 18°C and minus 3°C.
  • Cool temperate climates, where the mean temperature of the warmest month is over 10°C, and the mean temperature of the coldest month is under minus 3°C.
  • Ice climates, where the mean temperature of the warmest month is under 10°C.
• Each type is further subdivided into sub-types on the basis of seasonal variations in the distributional pattern of rainfall and temperature. Koeppen used letter symbols to denote climatic types. He used S for semi-arid and W for arid and the following small letters to define sub-types: f (sufficient precipitation), m (rain forest despite a dry monsoon season), w (dry season in winter), h (dry and hot), c (less than four months with mean temperature over 10°C), and g (Gangetic plain).
• Koeppen divided India into nine climatic regions. Hence, statement 1 is not correct. Hence, statement 2 is correct.

• The Himalayan ranges show a succession of vegetation from the tropical to the tundra, which changes with altitude.
• Deciduous forests are found in the foothills of the Himalayas.
• It is succeeded by the wet temperate type of forests between an altitude of 1,000-2,000 m.
• In the higher hill ranges of northeastern India, hilly areas of West Bengal and Uttaranchal, evergreen broad leaf trees such as oak and chestnut are predominant.
• Between 1,500-1,750 m, pine forests are also well-developed in this zone, with Chir Pine as a very useful commercial tree. • Deodar, a highly valued endemic species grows mainly in the western part of the Himalayan range.
• Deodar is a durable wood mainly used in construction activity.
• Similarly, the chinar and the walnut, which sustain the famous Kashmir handicrafts, belong to this zone. • Blue pine and spruce appear at altitudes of 2,225-3,048 m.
• At many places in this zone, temperate grasslands are also found.
• But in the higher reaches there is a transition to Alpine forests and pastures.
• Silver firs, junipers, pines, birch and rhododendrons, etc. occur between 3,000-4,000 m.
• However, these pastures are used extensively for transhumance by tribes like the Gujjars, the Bakarwals, the Bhotiyas and the Gaddis.
• The southern slopes of the Himalayas carry a thicker vegetation cover because of relatively higher precipitation than the drier north-facing slopes.
• At higher altitudes, mosses and lichens form part of the tundra vegetation.
• Hence, option (d) is the correct answer.