Explanation: Ringworm (also known as Dermatophytosis or Tinea infection) is a fungal skin disease. It appears as red, circular, itchy patches on the skin, scalp, or nails. Despite its name, it is not caused by a worm but by a fungus that grows on keratinized tissues such as skin, hair, and nails. The disease spreads through direct contact with infected individuals, animals, or contaminated objects.

Common Types:

• Tinea capitis: Ringworm of the scalp
• Tinea corporis: Ringworm of the body
• Tinea pedis: Athlete’s foot (infection of feet)
• Tinea cruris: Jock itch (infection of groin area)

Explanation: Inside a sealed pressure cooker, the pressure is higher than atmospheric pressure, which raises the boiling point of water to about 121℃. This allows food to cook faster because water and steam reach higher temperatures than at normal atmospheric pressure.

Explanation: Cobalt-60 (Co-60) is a radioactive isotope of cobalt that emits high-energy gamma rays during its decay process. It decays into Nickel-60 (Ni-60) by beta decay, releasing two strong gamma photons of energies 1.17 MeV and 1.33 MeV. Due to these intense gamma emissions, Co-60 is widely used in radiation therapy (teletherapy) for cancer treatment, as well as in industrial radiography and sterilization of medical equipment. Gamma rays have high penetration power, allowing them to destroy cancerous cells deep inside tissues.

Explanation: Wind energy is a clean and renewable source of energy that does not cause environmental pollution. It is generated by converting the kinetic energy of moving air into mechanical or electrical energy using wind turbines. Unlike fossil fuels such as coal or mineral oil, wind energy does not release carbon dioxide, sulfur dioxide, or other greenhouse gases. It is, therefore, a pollution-free and sustainable source of power, widely used for electricity generation in wind farms.

Explanation: Mucor is not a biofertilizer; it is a saprophytic fungus that grows on decaying organic matter. Biofertilizers are living microorganisms that enhance soil fertility by fixing atmospheric nitrogen or solubilizing nutrients. Examples include Rhizobium, Azotobacter, and Anabaena.

Explanation: Fish respire through specialized organs called gills, located on either side of their head. Gills contain thin filaments with a large surface area and rich blood supply that allow exchange of gases. When water passes over the gill membranes, oxygen diffuses into the blood and carbon dioxide diffuses out. This process enables aquatic respiration and supports survival underwater.

Explanation: Sound waves travel fastest in solids, slower in liquids, and slowest in gases. This is because the speed of sound depends on the elasticity and density of the medium — it travels faster when particles are tightly packed and can transmit vibrations more efficiently. Among the options, iron (a solid) allows sound to travel much faster (around 5130 m/s) than in water (1500 m/s), ice (3200 m/s), or air (331 m/s at 0°C).

Explanation: The King Cobra (Ophiophagus hannah) is the world’s longest venomous snake and the only snake species that builds a nest to lay its eggs. The female collects leaves, twigs, and debris to construct a mound-like nest, usually near dense vegetation or fallen logs. She lays about 20–40 eggs in the nest and guards them aggressively until they hatch, showing remarkable parental care — a rare behavior among reptiles.

Once the eggs are about to hatch, the female leaves the nest to avoid eating her own offspring, as King Cobras are carnivorous and feed mainly on other snakes.