Explanation: The liver is the largest gland in the human body. It is located in the upper right part of the abdomen, just below the diaphragm. The liver performs multiple vital functions, including the secretion of bile (which helps in digestion of fats), detoxification of harmful substances, storage of glycogen (energy reserve), and the synthesis of proteins and cholesterol. It also plays a crucial role in regulating blood sugar levels and metabolism. The average adult human liver weighs about 1.2 to 1.5 kilograms.

Explanation: In household electrical wiring, all the given statements are correct: the red insulated wire is the live (phase) wire, the black insulated wire is the neutral wire, and the green insulated wire is used for earthing to ensure safety by preventing electric shocks.

Chandrayaan-2, launched by the Indian Space Research Organisation (ISRO) on 22 July 2019, was designed to explore the South Pole region of the Moon. This area is of great scientific interest because it is permanently shadowed and may contain water ice and other valuable minerals. The mission included an orbiter, a lander (Vikram), and a rover (Pragyan), making it India’s first attempt at a soft landing on the lunar surface near the south pole.

Other options (for context)

• Moon North Pole: Not the target area of Chandrayaan-2.
• Moon North-West part: Incorrect — Chandrayaan-2 focused specifically on the South Pole.
• Unexplored part of the Moon: Partly true, but specifically, the unexplored South Pole region was chosen.

In organic farming, chemical fertilizers are not used. Instead, farmers rely on natural manures, compost, and biofertilizers to enrich the soil. Organic farming avoids synthetic pesticides and focuses on maintaining ecological balance, soil fertility, and sustainable crop production.

• Intercropping: Often used to increase productivity naturally.
• Manures: Essential in organic farming for soil health.
• Biofertilizers: Widely used to promote natural nutrient availability.

Explanation: The gas used for artificial ripening of green fruits is ethylene (C₂H₄). Ethylene is a natural plant hormone that regulates fruit ripening by stimulating the conversion of starches into sugars, making the fruit softer and sweeter. In artificial ripening, ethylene gas is introduced in controlled amounts to uniformly ripen fruits such as bananas, mangoes, and tomatoes. However, the use of harmful chemicals like calcium carbide for ripening is banned because it produces toxic substances like acetylene.

Explanation: A concave mirror can produce an image that is larger than the object when the object is placed between the mirror’s pole and its focal point. This property makes concave mirrors useful in applications like shaving mirrors and makeup mirrors, where magnified images are needed.

Explanation: Animals that live in or on trees are called arboreal animals. They are adapted to climbing and moving about among branches. Examples include monkeys, squirrels, chameleons, and tree frogs. Their adaptations may include grasping limbs, prehensile tails, claws, or adhesive pads that help them cling to tree surfaces and move efficiently among branches.

Carbon dioxide (CO₂) is commonly used as a fire extinguisher gas. It works by displacing oxygen around the fire and forming a blanket of gas that cuts off the oxygen supply, thereby stopping the combustion process. Additionally, CO₂ is non-flammable and leaves no residue, making it ideal for use on electrical and electronic fires where water cannot be used safely.

Other options (for context)

• Nitrogen dioxide (NO₂): A toxic gas, not suitable for firefighting.
• Carbon monoxide (CO): A poisonous gas produced by incomplete combustion, not used in extinguishers.
• Nitrous oxide (N₂O): Commonly known as laughing gas, used as an anesthetic, not a fire suppressant.