UPSC Civil Services Previous Year 2020 Question Papers With Answer Key

1 .

What is the use of biochar in farming?

1. ‘Biochar can be used as a part of the growing medium in vertical farming.

2. When biochar is a part of the growing medium, it promotes the growth of nitrogen-fixing microorganisms.

3. When biochar is a part of the growing- medium, it enables the growing medium /to retain water for longer time.

Which of the statements given above is/are correct?

A)

1 and 2 only

B)

2 only

C)

1 and 3 only

D)

1, 2 and 3

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

Note :

Biochar has the potential to produce farm-based renewable energy in an eco-friendly way. Specifically, the quality of biochar depends on several factors, such as the type of soil, metal, and the raw material used for carbonization, the pyrolysis conditions, and the amount of biochar applied to the soil.

In addition, the biochar amendment to the soil proved to be beneficial to improve soil quality and retain nutrients, thereby enhancing plant growth. Since biochar contains organic matter and nutrients, its addition increased soil pH, electric conductivity (EC), organic carbon (C), total nitrogen (TN), available phosphorus (P), and the cation-exchange capacity (CEC).

Earlier, reported that the biochar application affected the toxicity, transport, and fate of various heavy metals in the soil due to improved soil absorption capacity. The presence of plant nutrients and ash in the biochar and its large surface area, porous nature, and the ability to act as a medium for microorganisms have been identified as the main reasons for the improvement in soil properties and increase in the absorption of nutrients by plants in soils treated with biochar.

Biochar application decreased the tensile strength of soil cores, indicating that the use of biochar can reduce the risk of soil compaction. A lot has already been discussed on the benefits of inoculation of rhizobacteria in soil, but the addition of biochar can also provide more nutrients to the soil, thus benefiting the agricultural crops. The mixing of the plant growth-promoting microorganisms with biochar was referred to as the best combination for growth and yield of French beans Therefore, all statements are correct.

Year : 2020

Category : General Studies

2 .

Consider the following statements :

1. Coal ash contains arsenic, lead and mercury.

2. Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment.

3. High ash content is observed in Indian coal.

Which of the statements given above is/are correct?

A)

1 only

B)

2 and 3 only

C)

3 only

D)

1, 2 and 3

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

Note :

Coal ash contains contaminants like mercury, cadmium and arsenic. Without proper management, these contaminants can pollute waterways, ground water, drinking water, and the air.

The burning of coal releases many pollutants - oxides of nitrogen (NOx) and sulfur (SOx) - and particulate matter. They also emit greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), which are known to contribute to global warming and climate change.

Coal India Limited announced that ash content of coal produced in the country is generally 25 to 45 % whereas average ash content of imported coal varies from 10 to 20 %. Indian Coal has comparatively higher ash content than imported coal due to drift theory of formation of coal deposits in India.

Year : 2020

Category : General Studies

3 .

In rural road construction, the use of which of the following is preferred for ensuring environmental sustainability or to reduce carbon footprint?

1. Copper slag

2. Cold mix asphalt technology

3. Geotextiles

4. Hot mix asphalt technology

5. Portland cement

Select the correct answer using the code given below :

A)

1, 2 and 3 only

B)

2, 3 and 4 only

C)

4 and 5 only

D)

1 and 5 only

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

Note :

• The usage of Copper slag reduces the usage of primary materials as well as reduces the construction depth which in turn reduces energy demand in building. So, (1) is correct.

• Cold asphalt mix is produced by mixing unheated mineral aggregate with either emulsified bitumen or foamed bitumen. Unlike hot mix asphalt (HMA), cold asphalt mix does not require any heating of aggregate which makes it economical and relatively pollution-free (no objectionable fumes or odours). So, (2) is correct and (4) is not correct.

• Geotextiles reinforces the soil by adding tensile strength to i. It is used as a rapid de watering layer in the roadbed. So, (3) is correct.

• Portland cement production needs energy and can impact the environment. So, (5) is not correct.

Year : 2020

Category : General Studies

4 .

Which of the following are the most likely places to find the musk deer in its natural habitat?

1. Askot Wildlife Sanctuary

2. Gangotri National Park

3. Kishanpur Wildlife Sanctuary

4. Manas National Park

Select the correct answer using the code given below :

A)

1 and 2 only

B)

2 and 3 only

C)

3 and 4 only

D)

1 and 4 only

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

Note :

The white-bellied musk deer or Himalayan musk deer (Moschus leucogaster) is a musk deer species occurring in the Himalayas of Nepal, Bhutan, India, Pakistan and China. It is found in Askot Wildlife Sanctuary and Gangotri National Park located in the Himalayan regions. It is listed as endangered on the IUCN Red List because of overexploitation resulting in a probable serious population decline. So, (1) and (2) are correct.

The Kishanpur Wildlife Sanctuary is a part of the Dudhwa Tiger reserve near Mailani in Uttar Pradesh, India and Musk deer is not found here. So (3) is not correct.

Manas National Park or Manas Wildlife Sanctuary is a national park, UNESCO Natural World Heritage site, a Project Tiger reserve, an elephant reserve and a biosphere reserve in Assam, India. The park is known for its rare and endangered endemic wildlife such as the Assam roofed turtle, hispid hare, golden langur and pygmy hog. Manas is famous for its population of the wild water buffalo. So (4) is not correct.

Year : 2020

Category : General Studies

5 .

Steel slag can be the material for which of the following?

1. Construction of base road

2. Improvement of agricultural soil

3. Production of cement

Select the correct answer using the code given below :

A)

1 and 2 only

B)

2 and 3 only

C)

1 and 3 only

D)

1, 2 and 3

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

Note :

Steel slag, a by-product of steel making, is produced during the separation of the molten steel from impurities in steel-making furnaces. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. It is used in various activities such as in road construction, these are the preferred aggregates as they harden well, enabling a thinner layer of pavement than what can be achieved with crushed stone aggregates. Slag is also very hardy, resistant to both weather and wear. So, statement 1 is correct.

Benefits of using steel slag for crops: Slag application favors the increase of pH and the availability of nutrients such as Ca, Mg, and Si in the soil, which leads to the increase in the absorption of these elements by the plant, favoring the growth and yield of the crops. So, statement 2 is correct.

Steel-slag can be used to produce energy-saving cement by co-grinding with OPC clinker and blast furnace slag. It can replace Portland cement in various applications and is especially suitable for projects where a low heat of hydration is required. So, statement 3 is correct.

Year : 2020

Category : General Studies

6 .

Which one of the following protected areas is the of the (Barasingha) that thrives well on hard ground well-known for conservation of a sub-species Indian swamp deer and is exclusively graminivorous ?

A)

Kanha National Park

B)

Manas National Park

C)

Mudumalai Wildlife Sanctuary

D)

Tal Chhapar Wildlife Sanctuary

Correct Answer : Kanha National Park

Note : The revival of BaraSingha, an endangered and endemic cervid, belonging to the cervidae family, in the Kanha Tiger Reserve is hailed as one of the most successful and inspiring conservation projects in the world. While Kanha’s name may be synonymous with the tiger, it is actually the hard ground barasingha that has consistently challenged the professionalism, including foresightedness and managerial adaptability, of the Kanha management.

Year : 2020

Category : General Studies

7 .

With reference to Indiaâ€™s biodiversity, Ceylon frogmouth, Coppersmith barbet, Gray-chinned minivet and White-throated redstart are

A)

Birds

B)

Primates

C)

Reptiles

D)

Amphibians

Correct Answer : Birds

Note : The Sri Lanka frogmouth, Sri Lankan frogmouth or Ceylon frogmouth (Batrachostomus moniliger) is a small frogmouth found in the Western Ghats of south India and Sri Lanka. It is a bird that reaches 23 centimetres (9.1 in) in length.

Year : 2020

Category : General Studies

8 .

Which of the following Protected Areas are located in Cauvery basin?

1. Nagarhole National Park

2. Papikonda National Park

3. Sathyamangalam Tiger Reserve

4. Wayanad Wildlife Sanctuary

Select the correct answer using the code given below:

A)

1 and 2 only

B)

3 and 4 only

C)

1, 3 and 4 only

D)

1, 2, 3 and 4

Correct Answer : Option (C) - 1, 3 and 4 only

Note :

Nagarhole National Park, also known as Rajiv Gandhi National Park, is in the Cauvery Basin in India's Karnataka State.

Papikonda National Park is located near Rajamahendravaram in the Papi Hills in East Godavari and West Godavari districts of Andhra Pradesh, and covers an area of 1,012.86 km2 (391.07 sq mi).It is an Important Bird and Biodiversity Area and home to some endangered species of flora and fauna. No part of Papikonda remains outside East and West Godavari districts after 2014 and after the construction of Polavaram Dam. It means it is not in cauvery basin.

Year : 2020

Category : General Studies

9 .

With reference to Indian elephants, consider the following statements :

1. The leader of an elephant group is a female.

2. The maximum gestation period can be 22 months.

3. An elephant can normally go on calving till the age of 40 years only.

4. Among the States in India, the highest elephant population is in Kerala.

Which of the statements given above is/are correct?

A)

1 and 2 only

B)

2 and 4 only

C)

3 only

D)

1, 3 and 4 only

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

Note :

Elephants live in small family groups led by old females (cows) and Gestation is the longest of any mammal (18–22 months). So, statement 1 and 2 are correct.

According to the report, released by the Ministry of Environment, Forests and Climate Change on August 12, Karnataka has the highest number of elephants (6,049), followed by Assam (5,719) and Kerala (3,054). So, statement 3 and 4 are not correct.

Year : 2020

Category : General Studies

10 .

With reference to the cultural history of India, consider the following pairs :

1. Parivrajaka — Renunciant and Wanderer

2. Shramana — Priest with a high status

3. Upasaka — Lay follower of Buddhism

Which of the pairs given above are correctly matched?

A)

1 and 2 only

B)

1 and 3 only

C)

2 and 3 only

D)

1, 2 and 3

Correct Answer : Option (B) - 1 and 3 only

Note :

Parivrajaka literary means a wandering mendicant, vagrant, recluse, an ascetic. Shramana is also the same. These were the monks or ascetics of the heterodox sects during the early India who didn’t follow the Brahmanical varnashrama dharma. Thus, pair (1) is correct while pair (2) is not correct.

Upasaka means a lay follower of Buddhism. He is the one who believes in the three oaths and follows the Buddha’s doctrine but doesn’t renunciate the material world altogether and doesn’t become a Bhikkhu in the Sangha. Thus, pair (3) is correct.

Year : 2020

Category : General Studies