UPSC Civil Services Previous Year 2021 Question Papers With Answer Key

GENERAL KNOWLEDGE

UPSC 2021 (Prelims & Mains) Questions

1 .

Water can dissolve more substances than any other liquid because

it is dipolar in nature

it is a good conductor of heat

it has high value of specific heat

it is an oxide of hydrogen

Correct Answer : Option (A) - it is dipolar in nature

Note :

Water is called the universal solvent because it is capable of dissolving more substances than any other liquid. Water can dissolve more substances than any other liquid because it is dipolar. Hence, Option A is correct.

Water molecules have a polar arrangement of oxygen and hydrogen atoms — one side (hydrogen) has a positive electrical charge and the other side (oxygen) had a negative charge.

This allows the water molecule to become attracted to many other different types of molecules.

Water can become so heavily attracted to a different compound, like salt (NaCl), that it can disrupt the attractive forces that hold the sodium and chloride in the salt compound together and, thus, dissolve it.

Because of its polarity, water can form electrostatic interactions (charge-based attractions) with other polar molecules and ions.

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Year : 2021

Category : General Studies

2 .

With reference to street-lighting, how do sodium lamps differ from LED lamps?

(1) Sodium Lamps produce light in 360 degrees but it is not so in the case of LED lamps.

(2) As street-lights, sodium lamps have longer life span than LED lamps.

(3) The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street-lighting.

Select the correct answer using the codes given below :

3 only

2 only

1 and 3 only

1, 2 and 3

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

Note :

LED Chips are mounted on a circuit board, so depending on the configuration, usually 180 degrees. This is typically an advantage because light is usually desired over a target area (rather than all 360 degrees around the bulb). So, statement 1 is correct.

Sodium lamps lifespan is around 14,000 hours. LEDs last longer than any light source commercially available on the market. LEDs are typically 40,000 - 60,000 Hours. So, statement 2 is not correct.

High-pressure sodium lamps (HPS) emit a broader spectrum of light than the low-pressure lamps, but they still have poorer color rendering than other types of lamps. Low-pressure sodium (LPS) lamps only give monochromatic yellow light and so inhibit color vision at night. LPS lamps in particular are monochromatic which means that the objects illuminated by them appear shadowy black rather than the color you would see during daylight. HPS lamps are better but are still surpassed by virtually every other light on the market. LEDs can be designed to generate the entire spectrum of visible light colors without having to use the traditional color filters required by traditional lighting solutions. So, statement 3 is correct.

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Year : 2021

Category : General Studies

3 .

The term 'ACE2' is talked about in the context of

genes introduced in the genetically modified plants

development of India's own satellite navigation system

radio collars for wildlife tracking

spread of viral diseases

Correct Answer : Option (D) - spread of viral diseases

Note :

Angiotensin-converting enzyme 2 (ACE2) is a protein on the surface of many cell types. It is an enzyme that generates small proteins – by cutting up the larger protein angiotensinogen –that then go on to regulate functions in the cell.

Using the spike-like protein on its surface, the SARS-CoV-2 virus binds to ACE2. Hence, ACE2 acts as a cellular doorway that is a receptor for the virus that causes COVID-19. The spike protein of SARS-CoV-2 can adopt at least 10 structural states in order to cling onto angiotensin-converting enzyme 2 (ACE2) receptor cells in humans.

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Year : 2021

Category : General Studies

4 .

Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kind of plastic?

Low-density polyethylene

Polycarbonate

Polyethylene telephthalate

Polyvinyl chloride

Correct Answer : Option (B) - Polycarbonate

Note : Bisphenol A (BPA) is a chemical produced in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins. Polycarbonate plastics have many applications including use in some food and drink packaging, e.g., water and infant bottles, compact discs, impact-resistant safety equipment, and medical devices.

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Year : 2021

Category : General Studies

5 .

'Triclosan', considered harmful when exposed to high levels for a long time, is most lilely present in which of the following?

Food preservatives

Fruit-ripening substances

Reused plastic containers

Toiletries

Correct Answer : Option (D) - Toiletries

Note : Triclosan is a lipophilic compound with antimicrobial properties. It is an ingredient added to many consumer products intended to reduce or prevent bacterial contamination. It is added to some antibacterial soaps and body washes, toothpastes, and some cosmetics. It also can be found in clothing, kitchenware, furniture, and toys.

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Year : 2021

Category : General Studies

6 .

Which one of the following is a reason why astronomical distances are measured in light-years?

Distances among stellar bodies do not change

Gravity of stellar bodies does not change

Light always travels in straight line

Speed of light is always same.

Correct Answer : Option (D) - Speed of light is always same.

Note : A light-year is the distance a beam of light travels in a vacuum in one year. The reasons for measuring astronomical distances in light years are familiar units like kilometers and miles are absurdly small for describing the vastness of the cosmos and the speed of light is both finite and constant with a value of approximately 2.998 x 108 m/s.

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Year : 2021

Category : General Studies

7 .

We adopted parliamentary democracy based on the British model, but how does our model differ from that model?

(1) As regards legislation, the British Parliament is supreme or sovereign but in India, the power of the Parliament to legislate is limited.

(2) In India, matters related to the constitutionality of the Amendment of an Act of the Parliament are referred to the Constitution Bench by the Supreme Court.

Select the correct answer using the code given below :

1 only

2 only

Both 1 and 2

Neither 1 nor 2

Correct Answer : Option (A) - 1 only

Note :

Parliamentary sovereignty means that parliament is superior to the executive and judicial branches of government, and can therefore enact or repeal any law it chooses. It is a cornerstone of the UK constitutional system. Parliament of India is neither sovereign nor supreme. The authority and jurisdiction of Parliament are limited by the Powers of the other organs, the distribution of legislative powers between the Union and the States, fundamental rights (Article 32), Judicial review and an independent judiciary. Parliament cannot alter the basic features of the Constitution. So, statement 1 is correct.

Matters related to the constitutionality of an amendment act can be referred by the SC to its constitutional bench. However it is not mandatory for the SC to refer the matter to constitution bench. In case of amendment of an ordinary act in many cases the matters related to its constitutionality are dealt by divisional benches. So, statement 2 is not correct.

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Year : 2021

Category : General Studies

8 .

With reference to the Union Government, consider the following statements :

(1) N. Gopalaswamy Iyengar Committee suggested that a minister and a secretary be designated solely for pursuing the subject of administrative reform and promoting it.

(2) In 1970, the Department of Personnel was constituted on the recommendation of the Administrative Reforms Commission, 1966, and this was placed under the Prime Minister’s charge.

Which of the statements given above is/are correct?

1 only

2 only

Both 1 and 2

Neither 1 nor 2

Correct Answer : Option (C) - Both 1 and 2

Note :

In 1949, the Gopalaswami Ayyangar Committee while recommending restructuring of the Central Secretariat, suggested that a Department should be identifi ed with a Secretary’s charge and a Ministry should be identified with a Minister’s charge. So, statement 1 is correct.

In 1954, on the recommendation of Paul H. Appleby report, an Organisation and Methods (O&M) Division was set up in the Cabinet Secretariat. In 1964, the O&M Division was transferred to the Ministry of Home Affairs, under the newly created Department of Administrative Reforms. In 1970, on the basis of the recommendations of the Administrative Reforms Commission, the Department of Personnel was set up in the Cabinet Secretariat. Since Cabinet secretariat falls under

the Prime Minister, it is safe to say the DoPT was placed under PM’s Charge. So, statement 2 is correct.

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Year : 2021

Category : General Studies

9 .

'Right to Privacy' is protected under which Article of the constitution of India?

Article 15

Article 19

Article 21

Article 29

Correct Answer : Option (C) - Article 21

Note : In August 2017,a nine-judge bench of the Supreme Court in Justice K. S. Puttaswamy (Retd) Vs Union of India unanimously held that Indians have a constitutionally protected fundamental right to privacy that is an intrinsic part of life and liberty under Article 21.

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Year : 2021

Category : General Studies

10 .

Consider the following statements :

(1) In India, there is no law restricting the candidates from contesting in one Lok Sabha election from three constituencies.

(2) In 1991 Lok Sabha Election, Shri Devi Lal contested from three Lok Sabha constituencies.

(3) As per the existing rules, if a candidate contests in one Lok Sabha election from many constituencies, his/her party should bear the cost of bye elections to the constituencies vacated by him/her in the event of him/her winning in all the constituencies.

Which of the statements given above is/are correct?

1 only

2 only

1 and 3

2 and 3

Correct Answer : Option (B) - 2 only

Note :

As per Section 33(7) of the RPA, one candidate can contest from a maximum of two constituencies (more constituencies were allowed until 1996 when the RPA was amended to set the cap at two constituencies). So, statement 1 is not correct

In 1991, Haryana deputy chief minister Devi Lal contested three Lok Sabha seats — Sikar, Rohtak and Ferozepur — as well as the Ghirai assembly seat. He lost them all. So, statement 2 is correct.

The costs of the by-elections in such cases are born by the Election Commission Of India. So, statement 3 is not correct

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Year : 2021

Category : General Studies

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