This page lists 95 previous year UPSC Civil Services Preliminary Examination (General Studies Paper-I) questions on the UPSC 2021 Prelims. Choose an option to see the correct answer and the full explanation on the same page.
Explanations state facts as they stood in the year each question was asked, so words like “recently” or “currently” refer to that year, not today. For the present position, check the latest Current Affairs.
Showing 41–50 of 95 questions
UPSC 2021Environment and Ecology · Pollution
Q41. Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following? 1. Brakes of motor vehicles 2. Engines of motor vehicles 3. Microwave stoves within homes 4. Power plants 5. Telephone lines Select the correct answer using the code given below.
Explanation
Magnetite particles are a highly magnetic mineral form of iron and are known to be present in air pollution. Exposure to airborne particulate matter (PM) is associated with pulmonary, cardiovascular and neurological problems.
Option 1 is correct: Vehicle brake systems are the major source of airborne magnetite at the roadside.
Option 2 is correct: Petrol and diesel-engine exhaust are also a source of airborne magnetite.
Option 4 is correct: Other sources of Magnetite pollution include Power plants. Options 3 and 5 are incorrect: Household microwave stoves and telephone lines not are established as sources of airborne magnetite particles. Other sources of Magnetite pollution include microwave Stoves within homes, As per WHO, Telephone lines produce low frequency, low energy electromagnetic fields which are the potential source of magnetite particles.
Exam tip:
For S5, Had telephone lines been a real source of neurodegenerative magnetite particles, the effects would have surfaced in public health long ago -- given our lifelong proximity. Since no such pattern is observed, the claim lacks merit. Hence likely false. Giving option B as correct.
UPSC 2021Environment and Ecology · Pollution
Q42. The ‘Common Carbon Metric’, supported by UNEP, has been developed for
Explanation
The Common Carbon Metric’ is a protocol developed by United Nations Environment Program’s Sustainable Buildings & Climate Initiative (UNEP-SBCI) for measuring energy use & reporting GHG emissions from Building Operations. Its purpose is to support greenhouse gas (GHG) emission’s reductions through accurate measurement of energy efficiency improvements in building operations.
UPSC 2021Environment and Ecology · Pollution
Q43. What is blue carbon?
Explanation
Blue Carbon is the carbon captured by the world’s ocean and coastal ecosystems. There are three types of coastal ecosystems -- mangroves, seagrasses and tidal marshes; these store half the "blue" carbon buried beneath the ocean floor. These areas absorb and store carbon at a much faster rate than other areas, such as forests, and can continue to do so for millions of years. The carbon found in coastal soil is often thousands of years old.
UPSC 2021Geography · Geomorphology
Q44. The black cotton soil of India has been formed due to the weathering of:
Explanation
Black cotton soil, also known as regur soil, is highly valued in India because of its excellent moisture-retaining properties and suitability for cotton cultivation. Black cotton soil is primarily formed from the weathering of basaltic rocks, which are a type of fissure volcanic rock. These basaltic rocks were originally erupted during the Cretaceous period as part of the Deccan Traps in the northwest Deccan plateau. The weathering process of these volcanic rocks releases minerals that, combined with climatic factors, result in the formation of the distinctive black soil. The high clay content of black cotton soil enables it to retain moisture efficiently. Its properties make it particularly suitable for cotton cultivation, hence the alternative name "black cotton soil."
UPSC 2021International Relations and Current Affairs · Current Affairs
Q45. Consider the following statements in respect of the ICC World Test Championship: 1. The finalists were decided by the number of matches they won. 2. New Zealand was ranked ahead of England because it won more matches than England. Which of the above statements is/are correct?
Explanation
Statement 1 is incorrect: Instead, the ranking was based on the percentage of points (PCT) earned from matches played. Due to COVID-19 disruptions, the ICC modified the ranking system in 2020, and PCT (Points Percentage System) be-came the deciding factor rather than just the number of wins.
Statement 2 is incorrect: England won more matches than New Zealand in the WTC cycle (England won 11, New Zealand won 7). However, New Zealand had a higher PCT (70%) compared to England (61.4%), securing their place in the final.
UPSC 2021International Relations and Current Affairs · Current Affairs
Q46. Consider the following statements: Statement 1: The United Nations Capital Development Fund (UNCDF) and the Arbor Day Foundation have recently recognized Hyderabad as 2020 Tree City of the World. Statement 2: Hyderabad was selected for the recognition for a year following its commitment to grow and maintain the urban forests. Which one of the following is correct in respect of the above statements?
Explanation
Statement 1 is incorrect: Hyderabad was recognized as the "2020 Tree City of the World", but not by the UNCDF. The recognition was given by the Food and Agriculture Organization (FAO) of the United Nations and the Arbor Day Foundation, not the United Nations Capital Development Fund (UNCDF).
Statement 2 is correct: Hyderabad was selected due to its urban afforestation initiatives, including the Haritha Haram Program, which focuses on increasing green cover and maintaining urban forests. The city met the Tree Cities of the World standards, which require maintaining urban greenery, community involvement, and sustainable forestry policies.
UPSC 2021International Relations and Current Affairs · Current Affairs
Q47. Consider the following statements: 1. 21st February is declared to be the International Mother Language Day by UNICEF. 2. The demand that Bangla has to be one of the national languages was raised in the Constituent Assembly of Pakistan. Which of the above statements is/are correct?
Explanation
Statement 1 is incorrect: 21st February is recognized as International Mother Language Day by UNESCO, not UNICEF. It was proclaimed by UNESCO in 1999 and observed worldwide since 2000. The day commemorates the 1952 Bengali Language Movement in East Pakistan (now Bangladesh), where protesters were killed for demanding Bangla as an official language.
Statement 2 is correct: In 1948, Dhirendranath Datta, a member from East Pakistan (now Bangladesh), raised the demand for Bangla to be recognized as one of the national languages of Pakistan in the Constituent Assembly of Pakistan. The West Pakistani leadership rejected the demand, leading to protests and eventually the Bengali Language Movement (Bhasha Andolon). This movement later contributed to the liberation of Bangladesh in 1971.
Additional insight:
United Nations Educational, Scientific and Cultural Organization The United Nations Educational, Scientific and Cultural Organization (UNESCO), established on 16 November 1945, is a specialized UN agency headquartered in Paris, France. With 194 member states and nearly 11 associate members, UNESCO promotes global peace and security through international collaboration in education, sciences, culture, and communication. Its initiatives include safeguarding cultural heritage, advancing literacy, fostering sustainable development, and supporting press freedom. UNESCO also designates World Heritage Sites and leads programs like the Man and the Biosphere (MAB). Focused on priorities such as Africa and gender equality, it plays a pivotal role in achieving the UN’s Sustainable Development Goals (SDGs).
UPSC 2021Environment and Ecology · Climate Change
Q48. With reference to the ‘New York Declaration on Forests’, which of the following statements are correct? 1. It was first endorsed at the United Nations Climate Summit in 2014. 2. It endorses a global timeline to end the loss of forests. 3. It is a legally binding international declaration. 4. It is endorsed by governments, big companies and indigenous communities. 5. India was one of the signatories at its inception. Select the correct answer using the code given below.
Explanation
Statement 1 is correct: The NYDF was launched and endorsed at the United Nations Climate Summit in New York on September 23, 2014. It was a significant global effort to address deforestation and promote forest conservation.
Statement 2 is correct: The NYDF sets a global timeline to end natural forest loss by 2030 and to restore 350 million hectares of degraded forest and agricultural land by the same year. It also aims to halve deforestation by 2020 (though this target was not met).
Statement 3 is incorrect: The New York Declaration on Forests (NYDF) is a voluntary and non-legally binding international declaration aimed at ending global deforestation.
Statement 4 is correct: The NYDF has been endorsed by a wide range of stakeholders, including national governments, multinational companies, NGOs, and indigenous communities. Over 200 entities have pledged their support.
Statement 5 is incorrect: India was not a signatory to the NYDF at its inception. While many countries, including the United States, Canada, and several European nations, endorsed the declaration, India has still not joined as a signatory.
Exam tip:
For S3, since when declarations become legally binding? Aren’t treaties there for that? Legally binding is strong requirement, seldom international declaration are legally binding, hence more likely false. Eliminating options B and C. Now as compare to S5(much more specific and hence easy to manipulate) S2 is much more general and practical to be false.
UPSC 2021Science and Technology · Space and Space Technology
Q49. Which one of the following is a reason why astronomical distances are measured in light-years?
Explanation
Astronomical distances are measured in light-years to effectively express the vast distances in space using a consistent and universal unit. A light-year represents the distance light travels in one year in a vacuum, which is approximately 9.46 trillion kilometers (5.88 trillion miles). Astronomers calculate the distances of stars and other celestial objects in the time it takes for light to reach us since estimating distances in miles or kilometres is inadequate on the cosmological scale. Since the speed of light is known to be constant throughout the universe and for high precision, astronomical distances are expressed in terms of light-years. The fastest light can move is in vacuum.
UPSC 2021Modern History · Indian National Movement III (1930-1947)
Q50. With reference to 8th August 1942 in Indian history, which one of the following statements is correct?
Explanation
Option (a) is correct: The Quit India Resolution was passed by the All India Congress Committee (AICC) on 8th August 1942 at Gowalia Tank Maidan (now August Kranti Maidan) in Bombay, marking the launch of the Quit India Movement against British rule. Key Features of the Resolution:
Demanded immediate end to British rule in India.
Proposed the formation of a provisional government after British withdrawal. Declared that India would not support Britain in World War II unless granted independence. Gandhi’s famous call: "Do or Die" encouraged mass civil disobedience.
Answer key for these questions
Q
UPSC year
Correct answer
41
2021
(b) 1, 2 and 4 only
42
2021
(a) Assessing the carbon footprint of building operations around the world
43
2021
(a) Carbon captured by oceans and coastal ecosystems
44
2021
(b) Fissure volcanic rock
45
2021
(d) Neither 1 nor 2
46
2021
(d) Statement 1 is not correct but Statement 2 is correct.
47
2021
(b) 2 only
48
2021
(a) 1, 2 and 4
49
2021
(d) The speed of light is always the same.
50
2021
(a) The Quit India Resolution was adopted by the AICC.
Frequently asked questions
How many previous year UPSC questions are there on all subjects?
This page covers 95 previous year UPSC Prelims GS Paper-I questions on the UPSC 2021 Prelims, asked between 1995 to 2024. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for all subjects?
Questions on the UPSC 2021 Prelims are available for 30 years, from 1995 to 2024. Use the Year filter to practise a single paper.