Exclusive for Subscribers from Monday to Friday: Have you ever thought why Air Quality Index, particulate matter with a diameter of 2.5 micrometres and particulate matter with a diameter of 10 micrometres are relevant to the UPSC Exam? What significance do topics like import management system for IT hardware, United Nations Relief and Works Agency, Palestinian National Authority and Hamas have for both the preliminary and main exams? You can learn more by reading the Indian Express UPSC Key for October 20, 2023.