Explanation: Humans first develop a set of 20 milk teeth (also called deciduous or primary teeth) — 10 in the upper jaw and 10 in the lower jaw. These teeth start erupting around 6 months of age and are eventually replaced by 32 permanent teeth (including 4 wisdom teeth). Milk teeth help in early chewing, speaking, and maintaining space for permanent teeth.

The Moon takes about 27.3 days to complete one revolution around the Earth with respect to the stars (called the sidereal month). However, due to the simultaneous movement of the Earth around the Sun, the Moon takes approximately 29.5 days to complete one full cycle of phases (from new moon to new moon), known as the synodic month. This period is commonly rounded to 28 days in general usage.

Other options (for context)

• 45 days: Much longer than the Moon’s actual orbital period.
• 50 days: Incorrect — the Moon completes more than one revolution in this time.
• 65 days: Far too long compared to the real lunar cycle.

PINAKA is an indigenously developed Multi Barrel Rocket Launch (MBRL) system designed and produced by the Defence Research and Development Organisation (DRDO) of India. It is capable of firing a salvo of rockets to deliver explosive warheads over large areas with high accuracy. Pinaka is primarily used by the Indian Army for long-range artillery support and has a range of up to 75 km in its upgraded version (Pinaka Mk-II).

Other options (for context)

• Anti-submarine torpedo and research vehicle: Refers to underwater weapon systems, not related to Pinaka.
• Aircraft carrier: A large naval vessel capable of carrying aircraft; Pinaka is not a ship.
• Guided missile frigate submarine warship: Refers to naval warships, not a land-based rocket launcher.

Explanation: The Cerebrum forms about 80% of the total brain mass. It is divided into two hemispheres and is responsible for higher brain functions such as thought, action, reasoning, and emotion. The Cerebellum lies below it and controls coordination and balance, while the Medulla oblongata manages vital involuntary functions.

Explanation: Groundnut (Arachis hypogaea) is a leguminous plant that exhibits geocarpy — after fertilization a downward-growing peg pushes the fertilized ovary into the soil and the pod (the fruit) matures below ground. Potato, carrot and onion are underground plant parts but are respectively a tuber (stem), root and bulb — not fruits.

Green leafy vegetables are a rich source of Folic Acid (Vitamin B₉). Folic acid is essential for the formation of red blood cells, DNA synthesis, and proper cell growth. It is particularly important for pregnant women, as it helps prevent neural tube defects in the developing fetus. Vegetables like spinach, kale, lettuce, and fenugreek leaves are excellent sources of folic acid.

Other options (for context)

• Citric acid: Found mainly in citrus fruits like oranges and lemons.
• Malic acid: Commonly present in apples and other fruits, not in leafy greens.
• None of these: Incorrect — folic acid is the correct nutrient associated with green leafy vegetables.

Explanation: Sodium hydroxide (NaOH) is a base, so it does not turn blue litmus paper red. Instead, it turns red litmus paper blue. In contrast, lemon juice, acetic acid, and hydrochloric acid are acidic and turn blue litmus red.