Physics & Materials Science

Statement 1 is incorrect: Nanoparticles can exist in nature (natural nanoparticles). Volcanic eruptions, forest fires, and natural weathering processes can all create nanoparticles. Statement 2 is correct: Some cosmetics incorporate nanoparticles of ingredients like zinc oxide or titanium dioxide for sun protection or other purposes. Statement 3 is also correct: The safety of nanoparticles in consumer products is a complex issue and a growing area of research. Some nanoparticles might pose potential health or environmental risks depending on their specific properties and how they interact with the body or the environment.

Water molecules are polar, meaning they have a positive charge on one end (the hydrogen atoms) and a negative charge on the other end (the oxygen atom). This polarity allows water molecules to attract and interact with other polar or charged molecules, facilitating the dissolution of a wide range of substances in water. Therefore, option (a) is correct.

Statement 1 is correct. Sodium lamps emit light in a 360-degree pattern, while LED lamps are directional. Statement 2 is incorrect. LED lamps generally have a longer lifespan compared to sodium lamps. Statement 3 is correct. Sodium lamps emit monochromatic light, whereas LED lamps offer a wider spectrum of visible light, providing significant colour advantages in street lighting.

Statement 1 is correct: The size of the hole in the lid regulates the amount of steam released. A larger hole permits more steam to escape, leading to reduced pressure and subsequently affecting the temperature. Statement 2 is incorrect: Boiling water can never exceed 100 degrees Celsius, regardless of the intensity of the flame beneath the pot. However, within a pressure cooker, the temperature can elevate to as high as 121 degrees Celsius. The heightened cooking temperature serves to decrease the cooking duration rather than the temperature itself. Statement 3 is correct: If the weight is heavier, it will require higher pressure to lift it, resulting in higher pressure inside the cooker before excess steam can escape. Higher pressure leads to a higher boiling point for the water inside the cooker, which in turn increases the cooking temperature. Conversely, if the weight is lighter, it results in a lower pressure inside the cooker and a lower boiling point for the water, leading to a lower cooking temperature.

The description mentions three spacecraft in an equilateral triangle formation with million-kilometre sides using lasers for measurement.
This matches the design of the Evolved Laser Interferometer Space Antenna (eLISA) mission.
eLISA is a proposed space observatory aiming to detect gravitational waves using precisely positioned spacecraft. Voyager-2 and New Horizons are single spacecraft on exploration missions, not designed for gravitational wave detection. LISA Pathfinder was a precursor mission to test technologies for eLISA, not the full mission itself. Therefore, based on the details provided, the experiment refers to the Evolved LISA mission.

Steel slag can be used for several purposes, and all of the options listed are valid applications. Statement 1 is correct. Steel slag is a common and cost-effective material for use in road base construction due to its high durability, strength, and drainage properties. Statement 2 is correct. Crushed steel slag can be used as an amendment for agricultural soil. It can improve drainage, provide some essential nutrients, and even help suppress weeds. Statement 3 is correct. Steel slag can be partially substituted for some raw materials in cement production, reducing the need for quarrying and lowering the environmental impact of cement manufacturing. Therefore, the correct answer is 1, 2, and 3.

Pair 1 is incorrect: The Belle II experiment is a particle physics experiment designed to study the properties of B mesons. It is not related to artificial intelligence. Pair 2 s correct: Blockchain technology is the underlying technology behind cryptocurrencies like Bitcoin. It is a distributed ledger technology that ensures secure and transparent transactions. Pair 3 is incorrect: CRISPR-Cas9 is a gene-editing technology used in the field of molecular biology to edit genes. It is not related to particle physics. Therefore, only pair 2 is correctly matched.

Statement 1 is correct: According to Einstein's General Theory of Relativity, gravity can bend light. This phenomenon is known as gravitational lensing. Statement 2 is correct: The General Theory of Relativity led to the prediction of an expanding universe, which has been confirmed by observational evidence. Statement 3 is correct: According to the General Theory of Relativity, the presence of matter and energy warps the fabric of space and time around it, which is the underlying cause of the gravitational force. So, all three statements are correct.

* The terms 'Event Horizon', 'Singularity', 'String Theory' and 'Standard Model' are associated with the observation and understanding of the Universe, particularly in the field of cosmology and astrophysics. * Event Horizon refers to the boundary around a black hole, beyond which nothing, not even light, can escape the black hole's gravitational pull. * Singularity refers to a point in spacetime where the gravitational field becomes infinite, such as at the center of a black hole, where the laws of physics as we know them break down. * String Theory is a theoretical framework in particle physics that attempts to unify all the fundamental forces of nature, including gravity, into a single coherent model. * Standard Model is the most comprehensive and well-tested theory in particle physics, which describes the fundamental particles and their interactions, except for gravity.

The movie The Man Who Knew Infinity is based on the life of the famous Indian mathematician Srinivasa Ramanujan. It portrays his journey from India to England and his collaboration with the British mathematician G.H. Hardy.