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The correct answer is Iron (III) oxide.

Key Points

• A thermite reaction is a highly exothermic chemical reaction between a metal powder and a metal oxide. The most common and typical version involves Aluminium powder and Iron (III) oxide (Fe2O3).
• In this process, Aluminium acts as a strong reducing agent because it has a higher affinity for oxygen than iron. It reduces the Iron (III) oxide to produce molten iron and Aluminium oxide (Al2O3).
• The reaction is represented by the chemical equation: Fe2O3 + 2Al → Al2O3 + 2Fe + Heat. The heat generated is so intense that the iron produced is in a liquid (molten) state.
• Because of the production of molten iron, this reaction is extensively used for welding broken railway tracks and heavy machinery parts on-site where traditional welding is difficult.
• While other metal oxides like Copper oxide or Chromium oxide can technically undergo similar reactions with aluminium, Iron (III) oxide is the standard "thermite" component used in industrial and civil engineering applications. Hence, the correct answer is Iron (III) oxide.

Additional Information

• History and Discovery: The thermite process was discovered and patented by the German chemist Hans Goldschmidt in the year 1893. It is often referred to as the Goldschmidt reaction or the aluminothermic process.
• Temperature: The reaction can reach temperatures of approximately 2500°C (4500°F), which is sufficient to melt almost any metal.
• Ignition: Thermite is stable at room temperature and requires a very high activation energy to start. Typically, a Magnesium ribbon or a mixture of Potassium Permanganate and Glycerin is used as a fuse to provide the initial heat required for ignition.
• Applications:
• Railway Industry: Used for Thermite Welding (or Exothermic Welding) to join rails together, ensuring a smooth surface for trains.
• Military: Used in incendiary weapons and grenades to destroy enemy equipment, as the molten iron can melt through thick armor or engine blocks.
• Metallurgy: Employed in the reduction of ores for metals that are difficult to extract using carbon, such as Chromium and Manganese.

Important Points

• Redox Nature: The thermite reaction is a classic example of a Redox (Reduction-Oxidation) reaction and a displacement reaction, where a more reactive metal (Aluminium) displaces a less reactive metal (Iron) from its oxide.
• Reactivity Series: The success of the reaction depends on Aluminium being positioned higher than Iron in the reactivity series of metals.
• Safety: Due to the extreme temperatures and the fact that it is nearly impossible to extinguish once started (as it carries its own supply of oxygen within the metal oxide), it poses significant fire hazards and requires specialized safety protocols.
• States of Matter: The reactants are usually in powdered form to increase the surface area, ensuring a faster and more consistent reaction rate upon ignition.

The correct answer is tertiary consumer

Explanation:

• Primary Producers (Trophic Level 1): These are organisms such as plants, algae, and certain bacteria that convert carbon dioxide into organic matter through photosynthesis. They form the base of the food chain.
• Primary Consumers (Trophic Level 2): These are herbivores that directly consume the primary producers. For example, a rabbit eating grass.
• Secondary Consumers (Trophic Level 3): These are carnivores or omnivores that eat primary consumers. For example, a snake eating a rabbit.
• Tertiary Consumers (Trophic Level 4): These are carnivores that eat secondary consumers. For example, an eagle eating a snake.

Wool is a biodegradable product as it can be broken down biologically into natural raw materials such as carbon dioxide, water and naturally occurring minerals.

The correct answer is Total resistance decreases.

Key Points

• In a parallel combination of resistors, the equivalent resistance (R_p) is calculated using the reciprocal formula: 1/R_p = 1/R₁ + 1/R₂ + ... + 1/R_n.
• When the resistance of one branch (e.g., R₁) is halved, its individual reciprocal value (1/R₁) effectively doubles because 1/(R/2) equals 2/R.
• This increase in one of the terms within the summation leads to a higher value for the total sum of reciprocals (1/R_p).
• Since the total resistance (R_p) is the inverse of this sum, an increase in the sum 1/R_p mathematically results in a decrease of the value R_p.
• A core principle of parallel circuits is that the total effective resistance is always strictly less than the resistance of the smallest individual branch; thus, lowering any single branch resistance inevitably pulls the total resistance even lower.

 Additional Information

• Circuit Characteristics:
• In a parallel network, the potential difference (voltage) across each branch remains constant, which is why household wiring utilizes this configuration.
• According to Ohm's Law (V = IR), if the total resistance of a circuit decreases while the voltage remains constant, the total current drawn from the power source must increase.
• Power and Energy:
• The total power dissipated in a parallel circuit is given by P = V²/R. As the equivalent resistance decreases, the overall power consumption of the circuit increases.
• Adding more branches in parallel or reducing the resistance of existing branches facilitates more paths for charge carriers, thereby reducing the overall impedance to current flow.

The hormone that helps during childbirth by contracting the uterus is Oxytocin. It stimulates powerful contractions that help in thinning and opening the cervix, move the baby down and out of the birth canal, push out the placenta, and limit bleeding at the site of the placenta.

The correct answer is Plant and Animal fossils.

Important Points

• Paleontology is the study of past life forms using fossils.
• An example of paleontology is the branch of geology that studies dinosaurs.
• The study of the forms of life existing in prehistoric or geologic times, as represented by the fossils of plants, animals, and other organisms.

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Additional Information

• Volcanology, also spelled vulcanology, the discipline of the geologic sciences that is concerned with all aspects of volcanic phenomena.
• Volcanology, A geologist uses a rock hammer to sample active pahoehoe lava for geochemical analysis on the Kilauea volcano, Hawaii.
• Meteorology is the study of the atmosphere, atmospheric phenomena, and atmospheric effects on our weather.
• The atmosphere is the gaseous layer of the physical environment that surrounds a planet. ... Meteorology is a subdiscipline of the atmospheric sciences, a term that covers all studies of the atmosphere.
• ​Petrology is the study of rocks - igneous, metamorphic, and sedimentary - and the processes that form and transform them.
• Mineralogy is the study of the chemistry, crystal structure, and physical properties of the mineral constituents of rocks.

The correct answer is 'Y' will react with a base to form salt and water. 

Concept:

Acids:

• They are sour in taste.
• They turn blue litmus red.
• Its pH value ranges from 1 to 7 on the pH scale.

Bases:

• They are bitter in taste and soapy to touch.
• They turn red litmus blue.
• Its pH value ranges from 7 to 14 on the pH scale.

Explanation:

• The aqueous solution of 'Y' turns blue litmus red.
• Acids turn blue litmus red. Therefore, Y is an acid.
• Element X burns in air to form Y.
• So, X will form an oxide Y when burnt in the air.
• Non-metallic oxides are acidic in nature.
• So, X should be a non-metal.
• Acid and base react to form salt and water.

'Y' is an acid that will react with a base to form salt and water. ​

The correct answer is Aswaghosha.

Key Points

• Kushan Emperor Kanishka is believed to have converted to Buddhism under the influence of the Buddhist scholar and monk Aswaghosha.
• Aswaghosha was a Buddhist philosopher and dramatist, considered the greatest poet and playwright in Sanskrit after Kalidasa.
• Aswaghosha played a crucial role in spreading Buddhism and is credited with converting the Kushan emperor Kanishka to Buddhism.
• Apart from his influential role, he is also known for his philosophical works and as the author of "Buddhacharita," a biography of Buddha.
• Emperor Kanishka is also well-known for convening the Fourth Buddhist Council in Kashmir, which was an attempt to discuss and reconcile differences in Buddhist doctrines.
• His reign marked a significant period of expansion and development for Buddhism, spreading it along the Silk Road into parts of Central Asia and China.
• Kanishka was a great patron of Buddhism, however, he also respected other religious traditions and included Zoroastrians, Greeks, and Hindus in his court.

Additional Information

• Agrasen:
• Maharaja Agrasen is a legendary figure and is known as the progenitor of the Agrawal community.
• He was a contemporary to the last Tirthankara, Mahavira.
• Birupaksha: 
• The term "Birupaksha" is most commonly associated with a deity worshipped in the Indian temples at Hampi and Pattadakal.

The correct answer is Tamil Nadu.

Key Points

• Jallikattu is typically practiced in the Indian state of Tamil Nadu as a part of Pongal celebrations on Mattu Pongal day, which occurs annually in January.
• It involves releasing a bull into a crowd of people where participants attempt to grab its hump and ride it for as long as possible.

Additional Information

• Maramadi Bull Surfing race is famous in Kerala.
• Vallam Kali or traditional snake boat race famous sport in Kerala.
• Hori Habba is another rural sport practiced mainly in the Shivamogga districts of Karnataka.
• Bullock cart race in Maharashtra was a popular tradition in various parts of the state known as Bailgada Sharyat.
• Pallanguzhi is a Tamil traditional indoor board game.
• Dhopkhel is a ball game from Assam state played between two teams during the festival of Bihu.
• Camel Racing is famous in Rajasthan.

The correct answer is Methane.

Important Points

• Biogas is consists of Methane**, Hydrogen, Carbon dioxide.**
• Methane is the Main Constituent of Gobar gas or Biogas.
• Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste.
• When organic matter, such as food scraps and animal waste, breaks down in an anaerobic environment, they release a blend of gases, primarily methane and carbon dioxide.
• Because this decomposition happens in an anaerobic environment, the process of producing biogas is also known as anaerobic digestion.
• Anaerobic digestion is a natural form of waste-to-energy that uses the process of fermentation to breakdown organic matter.
• Animal manure, food scraps, wastewater, and sewage are all examples of organic matter that can produce biogas by anaerobic digestion.
• Due to the high content of Methane in biogas ( 50-75%), biogas is flammable, and therefore produces a deep blue flame, and can be used as an energy source.
• Biogas also called an environmentally friendly energy source.