UPSC Essentials brings to you its initiative of subject-wise quizzes. These quizzes are designed to help you revise some of the most important topics from the static part of the syllabus. Attempt today’s subject quiz on Environment and Geography to check your progress. 🚨 Click Here to read the UPSC Essentials magazine for September 2025. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com🚨 QUESTION 1 With reference to the Sir Creek, consider the following statements: 1. It is a 96-km tidal estuary located between West Bengal in India and Bangladesh. 2. It flows into the Bay of Bengal 3. It directly impacts maritime boundary delimitation and Exclusive Economic Zones (EEZs). How many of the statements given above are correct? (a) Only one (b) Only two (c) All three (d) None Explanation — Union Defence Minister Rajnath Singh warned Pakistan over the Sir Creek region, reiterating India’s firm stance on the subject of its territorial integrity. — Sir Creek was originally named ‘Ban Ganga’ and got its present name after a British official. The creek is a 96-km tidal estuary along the India-Pakistan border, located between Gujarat in India and Sindh in Pakistan. Hence, statement 1 is not correct. — It flows into the Arabian Sea and lies at the heart of a prolonged dispute over maritime boundaries, control of natural resources, and strategic dominance. Hence, statement 2 is not correct. — It directly impacts maritime boundary delimitation and Exclusive Economic Zones (EEZs) in the Arabian Sea. EEZs or exclusive economic zones are areas of the ocean, generally extending 200 nautical miles (230 miles) beyond a nation’s territorial sea, within which they have jurisdiction over both living and non-living resources. Hence, statement 3 is correct. Therefore, option (a) is the correct answer. QUESTION 2 The Acoustic Vehicle Alerting System (AVAS) is related to: (a) e-vehicles (b) Hydrogen vehicles (c) CNG vehicles (d) Petrol vehicle Explanation — In a step to curb road accidents involving electrified vehicles, the Ministry of Road Transport and Highways (MoRTH) has proposed an acoustic vehicle alerting system (AVAS) for all electric cars, buses and trucks. — AVAS is a device that will generate sound if the vehicle is moving at a speed up to 20 kmph to alert road users, especially pedestrians. — According to the draft notification issued on September 23, all new models of electric vehicles, including both passengers and goods, manufactured after October 1, 2026, will have to be fitted with Acoustic Vehicle Alerting System to meet the requirements with regard to audibility. For the existing models, the cut-off date is October 1, 2027 and after that they too will have to install AVAS in the vehicles. Therefore, option (a) is the correct answer. QUESTION 3 With reference to the climate models, consider the following statements: 1. It is a computer simulation that uses mathematical formulae and algorithms to replicate the Earth’s climate system. 2. It can forecast how variables such as temperature and humidity will change over time under different scenarios. 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 Explanation — A climate model is a computer simulation that uses mathematical formulae and algorithms to replicate how the Earth’s climate system — including the atmosphere, ocean, land and ice — works. Hence, statement 1 is correct. — These models are built on the principles of physics, chemistry, and biology, and are designed to simulate or mimic the interactions between the atmosphere, oceans, land surface, and ice. — Climate models can forecast how variables such as temperature and humidity will change over time under different scenarios, like increased greenhouse gas emissions or changes in land use. Simply put, they allow scientists to test hypotheses and draw conclusions on past and future climate systems. Hence, statement 2 is correct. — This also helps them to determine if abnormal weather events like extreme heavy rainfall are a result of changes in climate or just part of routine climate variation. Therefore, option (c) is the correct answer. QUESTION 4 The carlsberg-ridge was recently in the news. It is located in: (a) Mediterranean Sea (b) Pacific Ocean (c) Atlantic Ocean (d) Indian Ocean Explanation — The Carlsberg Ridge is a major segment of the mid-ocean ridge system in the Indian Ocean, formed by seafloor spreading between the Indian Plate and the Somali Plate. — It is estimated that the current phase of opening of the Carlsberg Ridge began at about 40 million years ago following a major plate reorganisation and its average spreading rate is of 2.4 to 3.3 cm — The ridge has a rough flanking topography and a median valley, which are the characteristics of slow-spreading ridges. — The ridge is known to host hydrothermal vent systems, potential sites of PMS deposits. India has conducted scientific research on these systems during the past three decades. — Strategically, the Carlsberg Ridge is particularly important because it is located much closer to India (around 2 degree north) compared with the Central and Southwest Indian Ridges (around 26 degree south). Therefore, option (d) is the correct answer. QUESTION 5 Consider the following statements: Statement 1: The average size of trees in the Amazon rainforest has been steadily increasing due to the rising levels of carbon dioxide (CO2) in the atmosphere. Statement 2: The rise of CO2 levels can benefit tree growth because of a phenomenon known as the carbon fertilisation effect. Which one of the following is correct in respect of the above statements? (a) Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1. (b) Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation for Statement 1. (c) Statement 1 is correct but Statement 2 is incorrect. (d) Statement 1 is incorrect but Statement 2 is correct. Explanation — The average size of trees in the Amazon rainforest has been steadily increasing due to the rising levels of carbon dioxide (CO2) in the atmosphere, according to a new study. The trees are increasing in size by more than three per cent every ten years, the analysis said. Hence, statement 1 is correct. — The study, ‘Increasing tree size across Amazonia’, was published in the journal Nature Plants on September 25. It was carried out by an international team of around 100 scientists from more than 60 universities around the world, including those from South America and the United Kingdom. — Usually, the average diameter of trees in an area of undisturbed old-growth forest stays roughly the same, as saplings take the place of fallen big trees and grow. Scientists believe that in the case of the Amazon rainforests, trees did not follow this trend due to a rise in atmospheric CO2, which increased by nearly a fifth in the last 30 years. — The rise of CO2 levels can benefit tree growth because of a phenomenon known as the carbon fertilisation effect. More CO2 in the atmosphere increases the rate of photosynthesis, leading to increased growth in some plants. Hence, statement 2 is correct. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1. Therefore, option (a) is the correct answer. Previous Daily Subject-Wise-Quiz Daily Subject-wise quiz — History, Culture, and Social Issues (Week 125) Daily subject-wise quiz — Polity and Governance (Week 130) Daily subject-wise quiz — Science and Technology (Week 130) Daily subject-wise quiz — Economy (Week 130) Daily subject-wise quiz — Environment and Geography (Week 129) Daily subject-wise quiz – International Relations (Week 129) Subscribe to our UPSC newsletter and stay updated with the news cues from the past week. Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us onInstagramand X.
