[DAY 32] 60 DAY RAPID REVISION (RaRe) SERIES for UPSC Prelims 2022 – GEOGRAPHY, CURRENT AFFAIRS & CSAT; Test Series, Videos & Notes!

Solution (d)

Basic Info:

-Alluvial soils are widespread in the northern plains and the river valleys. These soils cover about 40 per cent of the total area of the country.

– They are depositional soils, transported and deposited by rivers and streams. Through a narrow corridor in Rajasthan, they extend into the plains of Gujarat. In the Peninsular region, they are found in deltas of the east coast and in the river valleys.

– The alluvial soils vary in nature from sandy loam to clay. They are generally rich in potash but poor in phosphorous.

– The colour of the alluvial soils varies from the light grey to ash grey. Its shades depend on the depth of the deposition, the texture of the materials, and the time taken for attaining maturity. Alluvial soils are intensively cultivated.

– Black soil, not alluvial soil, swell and become sticky when wet and shrink when dried.

Solution (c)

Basic Info:

Black soils are also also known as the ‘Regur Soil’ or the ‘Black Cotton Soil’.

Black soil covers most of the Deccan Plateau which includes parts of Maharashtra, Madhya
Pradesh, Gujarat, Andhra Pradesh and some parts of Tamil Nadu. In the upper reaches of
the Godavari and the Krishna, and the north western part of the Deccan Plateau, the black
soil is very deep.

These are generally clayey, deep and impermeable. They swell and become sticky when wet and shrink when dried. So, during the dry season, these soil develop wide cracks. Thus, there occurs a kind of ‘self ploughing’.

Because of this character of slow absorption and loss of moisture, the black soil retains the
moisture for a very long time, which helps the crops, especially, the rain fed ones, to sustain
even during the dry season.

Solution (b)

Basic Info:

Red soil develops on crystalline igneous rocks in areas of low rainfall in the eastern and
southern part of the Deccan Plateau. Along the piedmont zone of the Western Ghat, long stretch of area is occupied by red loamy soil.

Yellow and red soils are also found in parts of Odisha and Chattisgarh and in the southern parts of the middle Ganga plain.

The soil develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks. It looks yellow when it occurs in a hydrated form.

The fine-grained red and yellow soils are normally fertile, whereas coarse-grained soils found in dry upland areas are poor in fertility.

This soil is deficient in nitrogen, humus, phosphoric acid, magnesium, and lime but fairly rich in potash, with its pH ranging from neutral to acidic.

Proper use of fertilizers and irrigation yields high production of cotton, wheat, rice, pulses, millets, tobacco, oil seeds, potatoes, and fruits.

Solution (b)

Basic Info:

Laterite soils are formed under the conditions of high temperature and heavy rainfall with alternate wet and dry periods. These are the result of intense leaching due to tropical rains.

Due to intensive leaching and low base exchange capacity, the laterite soils generally lack fertility.

They are mainly found on the summits of western ghats, eastern ghats and rajmahal hills.

These soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are in excess. Hence, laterites are not suitable for cultivation.

Laterite soils are most favoured in the building construction materials. These soils can be easily cut with a spade and don’t weather much. Hence, indefinitely durable.

Solution (b)

Basic Info:

Soil is the mixture of rock debris and organic materials which develop on the earth’s surface. In ancient times, soils used to be classified into two main groups – Urvara and Usara, which were fertile and sterile, respectively.

Solution (b)

Basic Info:

Tropical Thorn Forests:
Tropical thorn forests occur in the areas which receive rainfall less than 50 cm. These consist of a variety of grasses and shrubs.

 It includes semi-arid areas of southwest Punjab, Haryana, Rajasthan, Gujarat, Madhya Pradesh, and Uttar Pradesh.

In these forests, plants remain leafless for the most part of the year and give an expression of scrub vegetation.  Important species found are babool, ber, and wild date palm, khair, neem, khejri, palas, etc. Tussocky grass grows upto a height of 2 m as the undergrowth.

Solution (b)

Basic Info:

Southern Mountain Forests:
 The southern mountain forests include the forests found in three distinct areas of Peninsular India viz; the Western Ghats, the Vindhyas and the Nilgiris.

As they are closer to the tropics, and only 1,500 m above the sea level, vegetation is temperate in the higher regions, and subtropical on the lower regions of the Western Ghats, especially in Kerala, Tamil Nadu, and Karnataka.

The temperate forests are called Sholas in the Nilgiris, Anaimalai and Palani hills.

Some of the other trees of this forest of economic significance include magnolia, laurel, cinchona, and wattle.

Such forests are also found in the Satpura and the Maikal ranges.

Solution (a)

Basic Info:

Arid soils range from red to brown in colour. They are generally sandy in structure and saline in nature. In some areas, the salt content is so high that common salt is obtained by evaporating the saline water.

Due to the dry climate, high temperature and accelerated evaporation, they lack moisture and humus. Nitrogen is insufficient and the phosphate content is normal.

Lower horizons of the soil are occupied by ‘kankar’ layers because of the increasing calcium content downwards. The ‘Kankar’ layer formation in the bottom horizons restricts the infiltration of water, and as such when irrigation is made available, the soil moisture is readily available for a sustainable plant growth.

Arid soils are characteristically developed in western Rajasthan, which exhibit characteristic arid topography.

Solution (a)

Basic Info:

Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water.

Few types of erosion:

Sheet erosion: The detachment and transportation of soil particles by flowing rainwater is called sheet or wash off erosion. This is a very slow process and often remain unnoticed.

Rill erosion: In rill erosion finger like rills appear on the cultivated land after it has undergone sheet erosion. These rills are usually smoothened out every year while forming. Each year the rills slowly increase in number become wider and deeper.

Rill erosion occurs when runoff water forms small channels as it concentrates down a slope. 

Gully erosion: Gully erosion happens when runoff concentrates and flows strongly enough to detach and move soil particles.

Solution (c)

Basic Info:

Salinization is the increase of salt concentration in soil and is, in most cases, caused by dissolved salts in the water supply.

Factors such as sea level rise, drought, usage of poor quality groundwater for irrigation and improper usage of fertilizers and pesticide has led to the soil becoming salt-affected.

Due to climate change, sea levels are rising, which further accelerates the process of salinization.

Solution (a)

Basic Info:

The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy.

The forest area is based on the records of the State Revenue Department, while forest cover is based on aerial photographs and satellite imageries.

Both forest area and forest covers vary from state to state.

Solution (d)

Basic Info:

 Mangroves grow along the coasts in the salt marshes, tidal creeks, mudflats and estuaries.
They consist of a number of salt tolerant species of plants. Crisscrossed by creeks of stagnant water and tidal flows, these forests give shelter to a wide variety of birds.

 In India, the mangrove forests spread over 6,740 sq. km which is 7 percent of the world’s
mangrove forests.

 They are highly developed in the Andaman and Nicobar Islands and the Sunderbans of West Bengal.  Other areas of significance are the Mahanadi, the Godavari, and the Krishna deltas.

Solution (c)

Basic Info:

These are the most widespread forests in India. They are also called the monsoon forests. They spread over regions which receive rainfall between 70-200 cm.

On the basis of the availability of water, these forests are further divided into moist and dry deciduous.

The Moist deciduous forests are more pronounced in the regions which record rainfall between 100-200 cm. These forests are found in the northeastern states along the foothills of Himalayas, eastern slopes of the Western Ghats and Odisha.

Teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood etc. are the main species of these forests.

Dry deciduous forest covers vast areas of the country, where rainfall ranges between
70 -100 cm. On the wetter margins, it has a transition to the moist deciduous, while on the
drier margins to thorn forests.

These forests are found in rainier areas of the Peninsula and the plains of Uttar Pradesh and Bihar.

As the dry season begins, the trees shed their leaves completely and the forest appears like a vast grassland with naked trees all around. Tendu, palas, amaltas, bel, khair, axlewood, etc. are
the common trees of these forests. In the western and southern part of Rajasthan, vegetation cover is very scanty due to low rainfall and overgrazing.

Solution (a)

Basic Info

Tropical Evergreen Forest
These forests are found in the western slope of the Western Ghats, hills of the north-eastern region and the Andaman and Nicobar Islands.  They are found in warm and humid areas with annual precipitation of over 200 cm and mean annual temperature above 22 degree Celsius.

Tropical evergreen forests are well stratified, with layers closer to the ground and are covered with shrubs and creepers, with short structured trees followed by a tall variety of trees

In these forests, trees reach great heights up to 60 m or above. There is no definite time for trees to shed their leaves, flowering, and fruition. As such these forests appear green all the year-round. Species found in these forests include rosewood, mahogany, ebony, etc.

Solution (a)

Basic Info:

North Antelope Rochelle coal mine in the Powder River Basin of Wyoming, USA, is the largest coal mine in the world.

China is the largest consumer of coal, and has comprised more than half of global consumption since 2011, with this share growing year upon year reaching 56% in 2020.

Solution (a)

Basic Info:

Coal reserves in India
Most of the world’s coal was formed in Carboniferous age (350 million years ago). It is the best quality of coal reserves, but India does not have this type of coalfields.

 Gondwana Coalfields were formed nearly 250 million years ago. They make up to 98 percent of the total reserves and 99 percent of the production of coal in India.

Tertiary coal is 15 to 60 million years old hence, its carbon content is very low. Mainly confined to the extra-Peninsula, the important areas of Tertiary coal include parts of Assam, Meghalaya, Arunachal Pradesh, Nagaland, Himalayan foothills of Darjeeling in West Bengal, Jammu and Kashmir, Uttar Pradesh, Rajasthan, Kerala, Tamil Nadu, and Puducherry.

On the basis of carbon content, Coal is of 4 types viz. Anthracite (80-95% C), Bituminous (60-80% C), Lignite (40-55% C), and Peat (less than 40% C).

Anthracite coal is very rare in India. Only Jammu & Kashmir has this type of coal reserves.

On the basis of metallurgical uses, Coal is of two types viz. Coking coal and non-Coking coal. Jharkhand produces more than 90% of India’s Coking coal.

Solution (b)

Basic Info:

Shale Gas reserves in India:
Oil Shales are usually fine-grained sedimentary rocks containing relatively large amounts of organic matter from which significant quantities of shale oil and combustible gas can be extracted by destructive distillation.

The Shale Gas Formations are spread over several sedimentary basins, such as Gangetic plain, Gujarat, Rajasthan, Andhra Pradesh and other coastal areas in the country, including hydrocarbon bearing ones— Cambay, Assam-Arkan & Damodar Basins, have large shale deposits.

Solution (c)

Basic Info:

Natural gas hydrates are a naturally occurring, ice-like combination of natural gas and water. They are mainly found in oceans and Polar Regions.

Gas hydrates are crystalline form of methane and water, and exist in shallow sediments of outer continental margins. They are envisaged as a viable major energy resource for future.

Promising sites of gas hydrates have been identified and surveyed in the Krishna‐Godavari (KG) and the Mahanadi basins

Methane gas hydrate is stable at the seafloor at water depths beneath about 500 m.

Known as flammable ice, methane hydrates are molecules of gas contained in an ice matrix found in permafrost regions of the arctic and on the seafloor at continental margins below 500 meters of depth.

Using methane from gas hydrate as an energy resource would be, compared to other hydrocarbons, relatively climate friendly as combustion of methane is twice as efficient as burning coal.

Solution (c)

Basic Info:

Bio-gas

Biogas is a renewable energy source. It refers to a mixture of different gases produced by
the breakdown of organic matter in the absence of oxygen.

Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste.

Biogas can be produced by anaerobic digestion with anaerobic organisms, which digest material inside a closed system, or fermentation of biodegradable materials.

Biogas is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulfide (H2S), moisture and siloxanes.

It can be compressed like CNG called BioCNG. Bio-CNG is cheaper and cleaner than conventional diesel. Vehicles can run solely on gas (dedicated), or on both diesel and gas (dual-fuel)

Solution (c)

Basic Info:

Non-Conventional Sources of Energy: Natural resources like wind, tides, solar, biomass etc. generate energy which is nonconventional sources of energy.

When we cannot reuse a source of energy after using it once we call them conventional sources of energy or non-renewable energy resources. They are the most important conventional sources of energy. These include coal, petroleum, natural gas and nuclear energy.

Oil is the most widely used source of energy.  Coal, petroleum and natural gas account for about 90% of world’s production of commercial energy and hydroelectric and nuclear power account for about 10%.

Solution (d)

 Statement Analysis:

Context – Pangong Tso lake was in news

Solution (d)

Statement Analysis:

 Context – Competition Commission of India suspended Amazon’s deal with Future Retail.

Solution (c)

Statement Analysis:

 Context – CSTO troops entered Kazakhstan to restore order.

Solution (c)

Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces. Biofilms could be used for wide applications (antibacterial, food fermentation, biofertilizer, filtration, biofouling, prevention of corrosion, antimicrobial agents, wastewater treatment, bioremediation and microbial fuel cells) in food, agricultural, medical, environment and other fields.

Context – Breakthrough in the applications of Biofilms.

Solution (d)

Statement Analysis:

Context – A heart from a genetically modified pig was transplanted into a human in USA recently

Solution (b)

In the mixture of 60 litre, Milk= (60 × 4)/5 = 48ltr, Water= (60× 1)/5 = 12ltr

New ratio, = 12 + 3 : 48 + 7

= 15 : 55

= 3 : 11

Solution (c)

Let alcohol = 6x, water = 5x

According to the question, 6x – 22 × 6/11: 5x – 22 × 5/11 + 22 = 9 : 13

6x – 12 : 5x – 10 + 22 = 9 : 13

13 (6x – 12) = 9 (5x + 12)

78x – 156 = 45x + 108

78x – 45x = 156 + 108

33x = 264 x = 8

Water after replacement = 5 × 8 – 10 + 22 = 40 + 22 = 52 litre

Solution (d)

Let the capacity of each be ‘a’ litre

Then quantity of milk in container after mixing is (   3/5 + 7/10 + 11/4)a

= ((3 × 6 + 7 × 3 + 11 × 2)/30)  a

= (61/30)a

And  quantity of water in container after mixing is (2/5 + 3/10 + 4/15)a

= (12+9+8/30)a

= 29/30a

required  ratio of milk to water after mixing = (61/30)a / (29/30)a

= 61:29

Solution (b)

Alcohol in 9 ml lotion = ( 50/100 ​×9)=4.5 ml

Water in it = 9−4.5=4.5 ml

Let x ml of water be added to it. Then, 4.5/9+x ​ = 30/100 ​

=3(9+x)=45

=3x=18

x=6 ml

Solution (b)

This paragraph tells us that the ignorant mind is filled with a clutter of misleading theories and facts. The clutter is a by-product of our ability, as a species, to recognize patterns and theorize based on these. But this very same genius for storytelling, along with our inability to recognize our own ignorance, can put us in undesirable situations.

Option b captures all the key ideas of the paragraph: (a) our mental clutter- a by-product of our storytelling ability, (b) our ignorance of our own ignorance, and (c) how this can hamper our judgement, leading us to undesirable situations.

Option a states that ability to recognize patterns and creatively formulate theories is the “greatest weakness of our species. The paragraph given does not say this. Also, this option does not touch upon our inability to detect our own ignorance, which is an important point made in the paragraph. Not only do we formulate theories out of irrelevant or misleading information, we are ignorant of this.

Option c states that our ignorance is “compounded” by our tendency to create stories out of the clutter in our minds. What the paragraph states is different. The paragraph states that our tendency to recognize patterns and tell stories based on these creates mental clutter. Also, option c does not talk of our inability to detect our own ignorance.

Option d states that our tendency to weave stories out of the mental clutter “often” leads to truly dangerous situations. This overemphasizes the point. The paragraph only mentions that our creative storytelling ability and ignorance of our own ignorance can “sometimes” lead to situations that are embarrassing, unfortunate, or downright dangerous. Further, this option too does not mention our inability to detect our own ignorance.