The terms ‘Event Horizon’, ‘Singularity’, ‘String Theory’ and ‘Standard Model’ are sometimes seen in the news in the context of
Answer & explanation
Answer: (a) Observation and understanding of the Universe
All four terms belong to physics and cosmology, the study of how the Universe is built and how it began. An event horizon and a singularity are parts of a black hole, and the Standard Model describes matter and its forces.
- ✓ (a) The event horizon is a black hole's boundary, inside which nothing can escape, and the singularity is the point at its centre where matter is crushed to infinite density. The Standard Model explains how the building blocks of matter interact. String theory is a physicists' theory of fundamental forces and matter. All four help us understand the Universe.
- ✗ (b) Eclipses are explained by the positions of the Sun, Earth and Moon and need none of these terms.
- ✗ (c) Launching satellites concerns rockets and orbits, not black holes or particle physics.
- ✗ (d) The origin of living organisms belongs to biology and evolution. NCERT ties 'singularity' to the Big Bang, the origin of the Universe.
Remember · Event horizon and singularity are black-hole terms; the Standard Model is particle physics; string theory is theoretical physics. All concern the Universe.
📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 2 (practise this chapter)
Sources
- Black Hole Anatomy, NASA Science ↗ “We can think of the event horizon as the black hole’s surface. Inside this boundary, the velocity needed to escape the black hole exceeds the speed of light, which is as fast as anything can go. … General relativity predicts that the very center of a black hole contains a point where matter is crushed to infinite density.”
- The Standard Model, CERN ↗ · reference work “The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces.”
- NCERT Class 11 · Fundamentals of Physical Geography, Chapter 2 “In the beginning, all matter forming the universe existed in one place in the form of a "tiny ball" (singular atom) with an”
Question and answer: UPSC's official GS Paper I (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·