Explanation: Prithvi was the first indigenously developed missile of India, designed under the Integrated Guided Missile Development Programme (IGMDP) launched in 1983 by the Defence Research and Development Organisation (DRDO). It is a surface-to-surface short-range ballistic missile (SRBM) capable of carrying both conventional and nuclear warheads. The Prithvi missile series includes Prithvi-I (Army version), Prithvi-II (Air Force), and Prithvi-III (Navy), with ranges varying from 150 km to 350 km.

Glaciers usually melt first at the bottom. The pressure at the base of a glacier is very high, which lowers the melting point of ice — a phenomenon known as pressure melting. Additionally, heat from the Earth’s crust and friction caused by glacier movement also contribute to faster melting at the base.

• Top surface: Exposed to air but melts slower due to lower pressure.
• Sides and middle surface: Experience less pressure and friction, so melting is slower.

Explanation: Oncology is a branch of medical science that focuses on the study, diagnosis, treatment, and prevention of cancers and tumours. The term is derived from the Greek word “onkos” meaning mass or tumour. A specialist in this field is called an Oncologist.

Major Branches of Oncology:

• Medical Oncology: Treatment using chemotherapy, targeted therapy, and immunotherapy.
• Surgical Oncology: Removal of tumours through surgery.
• Radiation Oncology: Treatment of cancer using radiation therapy.

Common Cancers Studied in Oncology: Lung cancer, breast cancer, skin cancer, leukemia (blood cancer), and prostate cancer.

Explanation: Diamond is the hardest natural form of carbon. In diamond, each carbon atom is covalently bonded to four other carbon atoms in a tetrahedral structure, forming a strong three-dimensional lattice. This arrangement makes diamond extremely hard, dense, and transparent. It is used in cutting, drilling, and polishing tools. In contrast, graphite (another allotrope of carbon) is soft and slippery because its carbon atoms are arranged in layers with weak forces between them.

Explanation: A Local Area Network (LAN) is a network of computers and peripherals confined to a small geographical area, such as a home, school, or office building. It enables resource sharing, file transfer, and communication among connected devices within the limited range.

Explanation: A light year is a unit used to measure stellar or astronomical distances. It is defined as the distance that light travels in one year in a vacuum. Since light moves at a speed of about 3 × 10⁸ m/s, one light year equals approximately 9.46 × 10¹² km. It is commonly used to express distances between stars and galaxies because these distances are too large to be measured in kilometers or miles.

Explanation: Marijuana is a psychoactive drug obtained from the female inflorescence (flowering tops) of the Cannabis sativa plant. It contains the active compound tetrahydrocannabinol (THC), which affects the central nervous system and alters mood and perception.

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.