UPSC Civil Services Previous Year 2020 Question Papers With Answer Key

1 .

In the context of India, which of the following is/are considered to be of practice(s) of eco-friendly agriculture?

1. Crop diversification

2. Legume intensification

3. Tensiometer use

4. Vertical farming

Select the correct answer using the code given below :

A)

1, 2 and 3 only

B)

3 only

C)

4 only

D)

1, 2, 3 and 4

Correct Answer : Option (D) - 1, 2, 3 and 4

Note :

Crop diversification refers to the addition of new crops or cropping systems to agricultural production on a particular farm taking into account the different returns from valueadded crops with complementary marketing opportunities. Introducing a greater range of varieties in a particular agro - ecosystem leads to diversification of agricultural production which can also increase natural biodiversity, strengthening the ability of the agro-ecosystem to respond to these stresses. So (1) is correct.

The discourse on Legume intensification is currently framed as ‘Sustainable Intensification’ (SI), and commonly encompasses three dimensions: (i) increased productivity; (ii) maintenance of ecosystem services; and (iii) increased resilience to shocks. So (2) is correct.

When the water pressure in the tensiometer is determined to be in equilibrium with the water pressure in the soil, the tensiometer gauge reading represents the matric potential of the soil. Such tensiometers are used in irrigation scheduling to help farmers and other irrigation managers to determine when to water. Its also considered as eco-friendly agriculture as it help control the excessive use of water distorting the quality of the soil. So (3) is correct.

Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and aeroponics. So (4) is correct.

Year : 2020

Category : General Studies

2 .

With reference to the current trends in the cultivation of sugarcane in India, consider the following statements :

1. A substantial saving in seed material is made when ‘bud chip settlings’ are raised in a nursery and transplanted in the main field.

2. When direct planting of setts is done, the germination percentage is better with single-budded setts as compared to setts with many buds.

3. If bad weather conditions prevail when setts are directly planted, single-budded setts have better survival as compared to large setts.

4. Sugarcane can be cultivated using settlings prepared from tissue culture.

Which of the statements given above is/are correct?

A)

1 and 2 only

B)

3 only

C)

1 and 4 only

D)

2, 3 and 4 only

Correct Answer : Option (C) - 1 and 4 only

Note :

Sugarcane is normally propagated by stalk cuttings consisting of 2 to 3 bud sett. In conventional system, about 6–8 tons seed cane /ha is used as planting material. Establishing the sugarcane crop using bud chips in place of setts could save about 80% by weight of the stalk material, however this technology has not been scaled up at commercial levels due to poor survival of bud chips under field conditions. So, statement 1 is correct.

The researchers found that the setts having two buds are giving germination about 65 to 70 % with better yield. Large setts have better survival under bad weather but single budded setts also gives 70% germination if protected with chemical treatment. So, statement 2 and 3 are not correct.

Planting is the most important and labour intensive operation in sugarcane cultivation. Sugarcane germination as well as yield is affected by planting material, layout, plant-population, method of planting and placement of bud etc. Planting material for vegetative propagation such as whole cane, setts having of single bud to six buds, settling prepared from tissue culture or single buds in nursery are being used. So, statement 4 is correct.

Year : 2020

Category : General Studies

3 .

With reference to solar water pumps, consider the following statements :

1. Solar power can be used for running surface pumps and not for submersible Pumps.

2. Solar power can be used for running centrifugal pumps and not the ones with piston.

Which of the statements given above is/are correct?

A)

1 only

B)

2 only

C)

Both 1 and 2

D)

Neither 1 nor 2

Correct Answer : Option (D) - Neither 1 nor 2

Note :

Solar water pumps are specially designed to utilize DC electric power from photovoltaic modules. The pumps must work during low light conditions, when power is reduced, without stalling or overheating. Low volume pumps use positive displacement (volumetric) mechanisms which seal water in cavities and force it upward. Lift capacity is maintained even while pumping slowly. These mechanisms include diaphragm, vane and piston pumps. These differ from a conventional centrifugal pump that needs to spin fast to work efficiently. Centrifugal pumps are used where higher volumes are required. So statement 2 is not correct.

A surface pump is one that is mounted at ground level. Surface pumps work well when they draw water through suction less than 10 or 20 feet. A submersible pump is one that is lowered into the water. Most deep wells use submersible pumps. And both are compatible with the photovoltaic array (For Solar power). So statement 1 is not correct.

Year : 2020

Category : General Studies

4 .

'The crop is subtropical in nature. A hard frost is injurious to it. It requires at least 210 frost-free days and 50 to 100 centimeters of rainfall for its growth. A light well-drained soil capable of retaining moisture is ideally suited for the cultivation of the crop.' Which one of the following is that crop?

A)

Cotton

B)

Jute

C)

Sugarcane

D)

Tea

Correct Answer : Cotton

Note :

Ideal conditions for the cotton plant are :

Temperature : Cotton grows in tropical and sub-tropical warm humid climate. Annual temperature required is between to 20 to 28 Degree C. Equitable temperature distribution and bright sunshine is desirable.

Rainfall : Annual Rainfall of 55 to 100 cm is ideal for cotton. However, rainfall during harvest is harmful.

Frost Free days : 180 frost free days are the bottom line for cotton cultivation. Atleast 210 frost free days are desirable for cotton production.

Soil : Fertile saline soil with high water retention capacity is ideal. Loamy soil with high calcium carbonate is best suited for cotton cultivation.

Year : 2020

Category : General Studies

5 .

With reference to pulse production in India, consider the following statements :

1. Black gram can be cultivated as both kharif and rabi crop.

2. Green-gram alone accounts for nearly half of pulse production.

3. In the last three decades, while the production of kharif pulses has increased, the production of rabi pulses has decreased.

Which of the statements given above is/are correct?

A)

1 only

B)

2 and 3 only

C)

2 only

D)

1, 2 and 3

Correct Answer : Option (A) - 1 only

Note :

During kharif, it is cultivated throughout the country. It is best suited to rice fallows during rabi in southern and south-eastern parts of India. Blackgram needs relatively heavier soils than greengram. So, statement 1 is correct.

Gram is the most dominant pulse having a share of around 40 percent in the total production followed by Tur/Arhar at 15 to 20 percent and Urad/Black Matpe and Moong (Greengram) at around 8-10 percent each. Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh and Karnataka are the top five pulses producing States. Productivity of pulses is 764 kg/ha. So, statement 2 is not correct.

In the last three decades, the production of kharif pulses first decreased then increased and the production of rabi pulses has also increased. So, statement 3 is not correct.

Year : 2020

Category : General Studies

6 .

Which one of the following statements best describes the term 'Social Cost of Carbon'? It is a measure, in monetary value, of the

A)

long-term damage done by a tonne of CO2, emissions in a given year.

B)

requirement of fossil fuels for a country to provide goods and services to its citizens, based on the burning of those fuels.

C)

efforts put in by a climate refugee to adapt to live in a new place.

D)

contribution of an individual person to the carbon footprint on the planet Earth.

Correct Answer : long-term damage done by a tonne of CO2, emissions in a given year.

Note : Scientists expect climate change to have increasingly negative consequences for society, from rising sea levels to more frequent heatwaves. There is broad agreement that initial, modest benefits – for instance, increased yields for some crops in some regions – will be outweighed by costs as temperatures rise. One way to get a handle on this question is through the Social Cost of Carbon (SCC), which tries to add up all the quantifiable costs and benefits of emitting one additional tonne of CO2, in monetary terms. This value can then be used to weigh the benefits of reduced warming against the costs of cutting emissions.

Year : 2020

Category : General Studies

7 .

According to India’s National Policy on Biofuels, which of the following can be used as raw materials for the production of biofuels?

1. Cassava

2. Damaged wheat grains

3. Groundnut seeds

4. Horse gram

5. Rotten potatoes

6. Sugar beet

Select the correct answer using the code given below :

A)

1, 2, 5 and 6 only

B)

1, 3, 4 and 6 only

C)

2, 3, 4 and 5 only

D)

1, 2, 3, 4, 5 and 6

Correct Answer : Option (A) - 1, 2, 5 and 6 only

Note : The National Policy on Biofuels expands the scope of raw material for ethanol production by allowing use of Sugarcane Juice, Sugar containing materials like Sugar Beet, Sweet Sorghum, Starch containing materials like Corn, Cassava, Damaged food grains like wheat, broken rice, Rotten Potatoes, unfit for human consumption for ethanol production.

Year : 2020

Category : General Studies

8 .

What is/are the advantage/advantages of zero tillage in agriculture?

1. Sowing of wheat is possible without burning the residue of previous crop.

2. Without the need for nursery of rice saplings, direct planting of paddy seeds in the wet soil is possible.

3 Carbon sequestration in the soil is possible.

Select the correct answer using the code given below :

A)

1 and 2 only

B)

2 and 3 only

C)

3 only

D)

1, 2 and 3

Correct Answer : Option (D) - 1, 2 and 3

Note : Zero Tillage is the process of agriculture that promotes conservation agriculture. Here the soil is not tilled and left with at least 30% of cover over soil which may be previous crop. When wheat seeds are sown in soil using happy seeder, the rice stalks act as mulch. It not only prevents harmful gases that are released when stubbles are burnt but also provides enhanced nutrients and improves moisture holding capacity of the soil. The same is also true for rice when it is directly sown without transplantation. As the soil is not tilled the remains of previous crop hold carbon and prevent it from entering atmosphere as carbon di oxide. All statements are correct.

Year : 2020

Category : General Studies

9 .

With reference to the period of Gupta dynasty in ancient India, the towns Ghantasala, Kadura and Chaul were well known as

A)

ports handling foreign trade

B)

capitals of powerful kingdoms

C)

places of exquisite stone art and architecture

D)

important Buddhist pilgrimage centres

Correct Answer : ports handling foreign trade

Note :

Both the coasts of India have been studded with a string of ports since the ancient time and involved in foreign trade.

During the Gupta era, the ports of the east coast, Tamralipti, Ghantashala, and Kadura handled the north-Indian trade with south-east Asia, and those of the west coast, Broach, Chaul, Kalyan and Cambray, traded with the Mediterranean and west Asia but the more southerly of these ports were outside Gupta control.

The export of spices, pepper, sandalwood, pearls, precious stones, perfumes, indigo, and herbs continued as before but the commodities that were imported differed from those of earlier times. Chinese silk came in greater quantity, as did ivory from Ethiopia. The import of horses, coming from Arabia, Iran, and Bactria, either overland to centres in the north-west or by sea to the west coast, increased during this period.

Year : 2020

Category : General Studies

10 .

If a particular plant species is placed under Schedule VI of The Wildlife Protection Act, 1972, what is the implication?

A)

A licence is required to cultivate that plant.

B)

Such a plant cannot be cultivated under any circumstances.

C)

It is a Genetically Modified crop plant.

D)

Such a plant is invasive and harmful to the ecosystem.

Correct Answer : A licence is required to cultivate that plant.

Note : The specified endemic plants in Schedule VI are prohibited from cultivation and planting. As such a licence is required to cultivate that plant.

Year : 2020

Category : General Studies