Explanation: Thiamine (Vitamin B₁) is a water-soluble vitamin essential for carbohydrate metabolism and proper functioning of the nervous system. Its deficiency causes beriberi, which manifests as muscle weakness, loss of appetite, fatigue, and nerve degeneration. There are two main types of beriberi: dry beriberi (affecting nerves) and wet beriberi (affecting the heart).

Rich Sources: Whole grains, legumes, nuts, meat, eggs, and yeast.

Explanation: CNG stands for Compressed Natural Gas. It is an eco-friendly fuel made primarily of methane (CH₄) and is used as an alternative to petrol and diesel. CNG burns cleanly, producing fewer pollutants and helping reduce air pollution.

Explanation: ROM (Read Only Memory) retains its data even when the power is turned off, making it non-volatile memory. It stores essential programs such as the computer’s firmware or BIOS, which are required for booting the system. In contrast, RAM loses all information when power is shut down.

Explanation: During photosynthesis, green plants use sunlight to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). The oxygen gas released in this process comes specifically from the splitting of water molecules — a reaction known as photolysis of water, which occurs in the light-dependent reaction inside the chloroplasts.

Chemical equation:

6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O

The oxygen atoms in the released O₂ come entirely from the original water molecules, as demonstrated by isotopic experiments using heavy oxygen (O¹⁸) tracers.

Explanation: Vitamin B₂ is also known as Riboflavin. It is a water-soluble vitamin that plays a vital role in the body’s energy production and cellular function. Riboflavin acts as a coenzyme in the metabolism of carbohydrates, fats, and proteins, helping to convert food into energy. It is also essential for maintaining healthy skin, eyes, and nerve functions. A deficiency of Vitamin B₂ can lead to cracked lips, sore throat, and inflammation of the tongue (a condition known as ariboflavinosis).

Explanation: A rainbow is formed due to the dispersion of sunlight into its constituent colors and total internal reflection inside water droplets in the atmosphere. The light entering a droplet is refracted, reflected internally, and then refracted again as it exits, producing the beautiful spectrum of colors.

Explanation: EDUSAT (Education Satellite) was launched by the Indian Space Research Organisation (ISRO) in September 2004. It was the first Indian satellite built exclusively for educational purposes, designed to provide distance learning and interactive education through satellite communication.

Explanation: A CD-ROM (Compact Disc Read-Only Memory) is an optical disk used to store large amounts of data. It is read using a laser beam in a CD drive and is commonly used for distributing software, music, and multimedia content.