UPSC Essentials: Science and Technology Quizzes

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 Science and Technology to check your progress. 🚨 Click Here to read the UPSC Essentials magazine for October 2026 . Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com🚨 With reference to the coronal mass ejection (CME), consider the following statements: 1. It is a magnetised plasma released from the Sun’s outer atmosphere. 2. When CMEs are directed towards the Earth, they can contribute to space-weather disturbances and affect satellites. 3. CMEs can be imaged only in two dimensions. How many of the statements given above are correct? (a) Only one (b) Only two (c) All three (d) None Relevance: The topic is relevant to solar physics, the Sun–Earth relationship and space-weather studies. It links to concepts such as solar activity, Earth’s magnetosphere, geomagnetic storms and their implications for space-based infrastructure. Explanation According to pib.gov.in, — “Scientists at the Indian Institute of Astrophysics (IIA), Bengaluru , an autonomous institute under the Department of Science and Technology, Government of India, have used India’s first space-based solar observatory, Aditya-L1, to gain new insights into how a solar eruption expands near the Sun. The team combined spectroscopic observations from the Visible Emission Line Coronagraph (VELC) onboard ISRO ’s Aditya-L1 with images from NASA’s Solar Dynamics Observatory (SDO) and three-dimensional modelling. Hence, statement 3 is not correct. — Predicting the speed and trajectory of a CME is therefore a matter of practical importance and depends critically on understanding how the eruption evolves in three dimensions near the Sun, where it is still rapidly changing. What is a coronal mass ejection? — A coronal mass ejection (CME) is a massive burst of hot, magnetised plasma released from the Sun’s outer atmosphere, known as the corona. As CMEs travel through interplanetary space, those directed towards the Earth can contribute to space-weather disturbances and affect satellites and communication, and are therefore an important subject of research. Hence, statements 1 and 2 are correct. — Studying CMEs in their early stages, however, is extremely challenging. Scientists typically rely on coronagraphs, which block the bright solar disk to reveal the faint outer corona. Most coronagraphs can only image the CME in two dimensions; they capture motion across the sky, but cannot directly measure how fast the plasma is moving toward or away from the observer. This is where VELC onboard Aditya-L1 provides additional information by using spectroscopy to measure the motion of hot plasma along the line of sight. — VELC is one of the primary scientific instruments onboard Aditya-L1. It is developed by IIA, Bengaluru with substantial support from ISRO. Unlike imaging-only coronagraphs, VELC records spectra – measuring how the motion of plasma shifts the frequency of the light it emits. This technique, known as Doppler spectroscopy, uses the same principle as traffic speed guns: a moving object shifts the frequency of the light it emits. If plasma is rushing toward the observer, its light is shifted to shorter (blue) wavelengths; if rushing away, toward longer (red) wavelengths.” Therefore, option (b) is the correct answer. With reference to the terahertz waves, consider the following statements: 1. These are electromagnetic waves. 2. They have a frequency corresponding to a wavelength range of 3 mm ~ 30 μm. 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 Relevance: The topic is relevant to the electromagnetic spectrum and the classification of electromagnetic radiation based on wavelength and frequency. It is important for understanding different regions of the electromagnetic spectrum and their technological applications. Explanation According to pib.gov.in, — “A new silicon chip that allows terahertz waves to pass through an engineered barrier with little loss, while carrying data at 100 Gbit/s, points to compact terahertz circuits for future 6G communication technologies. — Future sixth-generation (6G) wireless networks are expected to use terahertz frequencies, which lie between microwaves and infrared light and offer wide bandwidth. Guiding these waves through compact circuits is challenging, as bends, junctions and abrupt changes in a waveguide can scatter or reflect part of the signal, weakening it as it travels. What are terahertz waves? — Terahertz waves are electromagnetic waves with a frequency of 0.1 – 10 THz, corresponding to a wavelength range of 3 mm ~ 30 μm.” Therefore, option (c) is the correct answer. With reference to the deficiency of vitamins and associated problems, consider the following pairs: 1. Vitamin D – Bone pain and muscle weakness 2. Vitamin B12 – Beriberi 3. Vitamin B1 – Anaemia How many of the pairs given above are correctly marked? (a) Only one pair (b) Only two pairs (c) All three pairs (d) None of the above pairs Relevance: The topic is relevant to human nutrition, micronutrients and their role in maintaining normal physiological functions. It links to the concepts of deficiency diseases, nutritional disorders and public health. Explanation — Vitamins are essential for several bodily functions, including metabolism and nerve health. Vitamins D, B12, and B1 are often discussed in the context of blood sugar management, particularly among people with diabetes or prediabetes. — Vitamin D may influence insulin sensitivity and the functioning of pancreatic beta cells, which produce insulin. Low vitamin D levels have been associated with insulin resistance, although this does not establish that supplements can prevent diabetes. Vitamin D is important for metabolic health, but a deficiency does not automatically mean that a person will develop diabetes. A deficiency may cause bone pain, muscle weakness, and fatigue. Blood levels can be assessed through a serum 25-hydroxyvitamin D test. Hence, pair 1 is correctly marked. — Vitamin B12 is important for nerve health, particularly in people with diabetes who are taking metformin. Vital for nerve function and red blood cell formation, a Vitamin B12 deficiency can cause weakness, fatigue, anaemia, tingling or numbness in the hands and feet. Hence, pair 2 is not correctly marked. — Vitamin B1, also known as thiamine, helps the body metabolise carbohydrates and supports nerve function. A deficiency may cause fatigue, poor appetite and neurological symptoms. Beriberi is caused by Vitamin B1 (thiamine) deficiency. Hence, pair 3 is not correctly marked. Therefore, option (a) is the correct answer. The objective of NASA’s ESCAPADE Mission is: (a) To study the geological composition and seismic activity of Mars to identify regions suitable for future human settlements. (b) To investigate the presence of liquid water beneath the surface of Mars using ground-penetrating radar. (c) To use two identical spacecraft to investigate how the solar wind interacts with Mars’ magnetic environment and how this interaction drives the planet’s atmospheric escape. (d) To study the composition of Jupiter’s atmosphere and its interaction with the planet’s powerful magnetic field. Relevance: The topic is relevant to planetary science, space exploration and recent developments in international space missions. It helps understand the scientific objectives, technological capabilities and applications of interplanetary exploration, an important area under Space Technology in the UPSC Prelims syllabus. Explanation — In a few days, NASA’s ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) will perform a maneuver that no agency spacecraft has flown before — and do it twice. Each of the two ESCAPADE spacecraft will execute a “powered” flyby of Earth, combining Earth’s gravity with an engine burn, to slingshot itself toward Mars. — As each spacecraft flies close to Earth, our planet’s gravity will speed it up and redirect it toward Mars. At the spacecraft’s closest approach to Earth, it will also perform a “trans-Mars injection burn,” firing its engine for about 9 minutes to give itself an extra boost toward the Red Planet. — The objective of the ESCAPADE Mission was to use two identical spacecraft to investigate how the solar wind interacts with Mars’ magnetic environment and how this interaction drives the planet’s atmospheric escape. Therefore, option (c) is the correct answer. (Source: science.nasa.gov ) The protective coatings — Titanium Aluminium Silicon Nitride (TiAlSiN) and Chromium Aluminium Silicon Nitride (CrAlSiN) are widely used for: (a) tungsten carbide cutting tools. (b) Solar photovoltaic cells. (c) Biomedical implants and prosthetic devices. (d) Anti-fouling coatings for marine vessels. Relevance: The topic is relevant to understanding advanced materials and their industrial applications. It links to material science, nanotechnology, surface engineering and the development of high-performance ceramic coatings. Explanation According to the pib.gov.in, — “An advanced surface-engineering approach developed by scientists can help improve the durability of cutting tools used for machining super alloys. — Scientists from the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad , an autonomous R&D Centre of the Department of Science and Technology (DST) have developed and evaluated two nanocomposite protective coatings—Titanium Aluminium Silicon Nitride (TiAlSiN) and Chromium Aluminium Silicon Nitride (CrAlSiN)—on widely used tungsten carbide cutting tools.” Therefore, option (a) is the correct answer. 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