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 June 2026. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.comWith reference to the ceramic-based lithium battery, consider the following statements:1. Unlike traditional lithium-ion batteries, which are flammable, the ceramic-based lithium battery operates stably at temperatures up to 150 degrees Celsius.3. These batteries use a liquid electrolyte as the medium through which lithium ions move to generate an electrical current.Which one of the following conclusions based on the above statements is correct?(a) There are two correct statements, that include statement 2.Story continues below this ad(b) There are two correct statements, that are statements 1 and 3.(c) There is only one correct statement.(d) All three statements are correct.Relevance: The topic is relevant under emerging battery technologies and advances in energy storage systems. UPSC can frame questions comparing conventional and next-generation battery technologies, focusing on materials, safety, and applications.Explanation— Chinese scientists have developed a ceramic-based lithium battery that is heatproof and could eventually offer a safe power source for smart sensors, aerospace gadgets, and other military applications. The Tsinghua University-led team, which invented it, said the all-ceramic battery’s compact size, high energy density, and safety features could make it well-suited for integration into next-generation technologies. Hence, statement 2 is correct.— Unlike traditional lithium-ion batteries, which are flammable, this rechargeable solid-state battery operates stably at temperatures up to 150 degrees Celsius. It can withstand brief thermal shocks up to 300 degrees Celsius without a drop in performance. Hence, statement 1 is correct.What are the challenges with traditional lithium-ion batteries?Story continues below this ad— Traditional lithium-ion batteries use a liquid electrolyte as the medium through which lithium ions move to generate an electrical current. They have become the default battery technology largely due to their high energy density. Traditional lithium-ion batteries fall short in security and thermal robustness. Hence, statement 3 is not correct.— One of the biggest concerns with traditional batteries is their flammability. Exposure to high temperatures or physical damage, such as punctures, can cause the volatile liquid electrolyte inside to catch fire or even explode. This severely restricts their use in critical applications such as fire alarm and monitoring systems, industrial Internet of Things sensors, aerospace equipment, and military and defence applications.Significance of ceramic solid-state batteries— All-ceramic solid-state batteries are seen as a promising option for miniature devices, but the Chinese researchers said they faced a critical challenge, a thickness-strength trade-off. Making the ceramic solid electrolyte thinner, which is formed by stacking layers of ceramic material, can weaken its mechanical strength and compromise its integrity.— The battery can be able to operate normally after experiencing a thermal shock of 300 degrees Celsius for 20 seconds. It is completely non-combustible and maintains structural integrity under sustained external combustion and has excellent thermal stability in air, significantly outperforming batteries with liquid, polymer, or composite electrolytes in terms of safety.Therefore, option (a) is the correct answer.QUESTION 2Consider the following statements:Story continues below this adStatement 1: Massive stars spend their lives generating enormous amounts of light and heat through a process called nuclear fusion.Statement 2: When the star runs out, the outward pressure that once kept gravity at bay disappears – and the star begins collapsing under its own weight.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.Story continues below this ad(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.Relevance: The question is important for understanding the life cycle of stars, including stellar evolution, supernovae, neutron stars, and black holes. UPSC frequently asks conceptual questions on astronomy where understanding nuclear fusion, gravity, and stellar collapse is essential.Explanation— Massive stars spend their lives generating enormous amounts of light and heat through a process called nuclear fusion. But eventually, even the largest of them run out. When that happens, the outward pressure that once kept gravity at bay disappears – and the star begins collapsing under its own weight, theoretically compressing all of its mass into a single, infinitely small point known as a singularity. Hence, statements 1 and 2 are correct.— This singularity is hidden by an event horizon, beyond which nothing, not even light, can escape. This region of spacetime is called a black hole.Story continues below this ad— Black holes are widely accepted by physicists, yet they continue to raise questions that science cannot fully answer. For instance, how can a mass equivalent to billions of Suns be squeezed into a point with no size? How can the known laws of physics – which break down entirely at a singularity – be trusted to describe what lies beyond the event horizon?— However, Statement 2 describes what happens after the fuel is exhausted, whereas Statement 1 describes how the star generates energy during its lifetime. Therefore, Statement 2 is not the correct explanation for Statement 1.Therefore, option (b) is the correct answerQUESTION 3With reference to the Gamma rays, consider the following statements:1. They are produced by the hottest and most energetic objects in the universe.2. Gamma rays can be captured and reflected by mirrors.Which of the statements given above is/are correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2Story continues below this adRelevance: The topic is important under astronomy and space science, especially in the context of high-energy astrophysics missions. It can be relevant for understanding the electromagnetic spectrum, a recurring conceptual area in UPSC science questions.Explanation— Nasa is preparing an unprecedented mission to save one of its most successful space telescopes from falling out of orbit and burning up in Earth’s atmosphere. The agency’s Neil Gehrels Swift Observatory, launched in 2004 to study powerful cosmic explosions known as gamma-ray bursts, is gradually losing altitude due to increasing atmospheric drag. Without intervention, scientists estimate the spacecraft could re-enter Earth’s atmosphere and be destroyed before the end of 2026.About Gamma rays— Gamma rays have the smallest wavelengths and the most energy of any wave in the electromagnetic spectrum.— They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay. Hence, statement 1 is correct.Story continues below this ad— Unlike optical light and x-rays, gamma rays cannot be captured and reflected by mirrors. Gamma-ray wavelengths are so short that they can pass through the space within the atoms of a detector. Hence, statement 2 is not correct.— Gamma-ray detectors typically contain densely packed crystal blocks. As gamma rays pass through, they collide with electrons in the crystal. This process is called Compton scattering, wherein a gamma ray strikes an electron and loses energy, similar to what happens when a cue ball strikes an eight ball. These collisions create charged particles that can be detected by the sensor.Therefore, option (a) is the correct answer.(Other Source: science.nasa.gov)QUESTION 4Consider the following statements about the Artemis Accords:1. It was established in 2020 to provide a common set of principles to enhance the governance of the civil exploration and use of outer space.2. It reinforces the commitment by signatory nations to the Outer Space Treaty.3. These are a legally binding international treaty.4. It prohibits the extraction and utilisation of space resources from the Moon.How many of the statements given above are correct?(a) Only one(b) Only two(c) Only three(d) All fourRelevance: Artemis Accords are increasingly important due to India’s growing role in global space governance and its participation in the Artemis Program through cooperation with NASA. The topic is important in the context of renewed lunar exploration missions and increasing international cooperation in space activities.Explanation— The Republic of Botswana will sign the Artemis Accords during a ceremony on June 25 at NASA Headquarters in Washington.— NASA, in coordination with the U.S. Department of State and seven other initial signatory nations, established the Artemis Accords in 2020. With many countries and private companies conducting missions and operations around the Moon, the Artemis Accords provide a common set of principles to enhance the governance of the civil exploration and use of outer space. Hence, statement 1 is correct.— The Artemis Accords reinforce the commitment by signatory nations to the Outer Space Treaty, the Registration Convention, the Rescue and Return Agreement, as well as best practices and norms of responsible behavior for civil space exploration and use. Hence, statement 2 is correct.— The Artemis Accords are not a legally binding international treaty; they are a set of non-binding political commitments among signatory nations. Hence, statement 3 is not correct.— The Accords do not prohibit the extraction and utilisation of space resources. Rather, they recognise that such activities can be conducted in a manner consistent with the Outer Space Treaty. Hence, statement 4 is not correct.Therefore, option (b) is the correct answer.(Source: http://www.nasa.gov)QUESTION 5With reference to the SYNCON (synchronous condenser), consider the following statements:1. A synchronous condenser is a generator that spins freely without producing electricity.2. It helps in maintaining stability during sudden fluctuations in power demand or supply.Which of the statements given above is/are correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2Relevance: The topic is relevant to India’s energy transition and the integration of renewable energy sources such as solar and wind. It can also be linked to topics such as power transmission, reactive power management, and energy security.Explanation— The Grid Controller of India (Grid India) identified nine thermal power units with a combined capacity of about 1.8 gigawatts (GW) that can be repurposed as synchronous condensers (SYNCONs), a move aimed at strengthening grid reliability as India navigates the challenges of integrating rapidly growing renewable energy capacity.— Of the shortlisted power plants, eight are coal- or lignite-based, while one is gas-based. All of them are either under prolonged outage or operating at very low utilisation levels, making them potential candidates for conversion rather than continued power generation.— A synchronous condenser is a generator that spins freely without producing electricity. Instead, it provides inertia, reactive power and voltage support to the grid, helping maintain stability during sudden fluctuations in power demand or supply. Grid operators often describe it as an electrical shock absorber that keeps the system balanced, particularly as increasing shares of solar and wind power reduce the stabilising influence provided by large thermal generators. Hence, statements 1 and 2 are correct.Therefore, option (c) is the correct answer.Previous Daily Subject-Wise-QuizDaily Subject-wise quiz — History, Culture, and Social Issues (Week 159)Daily subject-wise quiz — Polity and Governance (Week 168)Daily subject-wise quiz — Science and Technology (Week 167)Daily subject-wise quiz — Economy (Week 167)Daily subject-wise quiz — Environment and Geography (Week 167)Daily subject-wise quiz – International Relations (Week 167)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 on Instagram and X.