Explanation

• The chemical name of chalk is Calcium carbonate.
• Its chemical formula is CaCO₃.
• It is a soft, white mineral.
• Commonly used in blackboard chalk and limestone.
• Found naturally in rocks and marine shells.

Last verified on 30-04-2026

Explanation

• Vitamin A is essential for vision, skin health, and immune function.
• Its deficiency can lead to night blindness (poor ight vision) and other health problems.

Additional information:

• Dry skin and eyes
• Impaired immune function
• Poor wound healing
• Increased risk of respiratory and urinary tract infections

Last verified on 17-01-2026

Explanation

• Ibn al-Haytham is known as the Father of Modern Optics.
• He made groundbreaking discoveries about light and vision.
• His famous book is Kitab al-Manazir (Book of Optics).
• His research was done around 1011–1021 AD.

Last verified on 27-04-2026

Explanation

• Rear view mirrors in vehicles are convex mirrors.
• They give a wider field of view.
• Images formed are virtual, upright, and smaller.
• This helps drivers see more traffic behind them.
• It is a curved mirror that bulges outward.
• It is commonly used in side mirrors of cars, buses, and motorcycles.

Last verified 26-04-2026

Explanation

• Chronometer is a highly precise time-measuring instrument.
• It is often used in navigation and scientific experiments.
• It is designed to measure time accurately, even under varying conditions.
• Chronometers played a key role in determining longitude at sea.

Last verified on 03-04-2026

Explanation

• Asthma is a chronic respiratory disease affecting the airways of the lungs.
• It causes narrowing and inflammation of the air passages, leading to difficulty in breathing.
• Common symptoms include wheezing, coughing, chest tightness, and shortness of breath.

Last verified on 02-04-2026

Explanation

• The 100 percent pure gold is 24-carat gold.
• Lower cartages contain less gold 18-carat gold contains 75 percent gold and 25 per cent other metals, often copper or silver.
• Carat is the unit of measurement for the physical weight of diamonds/gold.

Last verified on 02-04-2026

Explanation

• Isaac Newton (1642–1727) was an English physicist and mathematician.
• He formulated the laws of motion and law of universal gravitation.
• His work laid the foundation for classical mechanics.

Last verified on 02-04-2026

Explanation

Explanation

• Average Distance: 3,84,400 km
• Orbit Period: 27.3 days
• Moon Diameter: 3,474 km
• Earth Diameter: 12,742 km
• Closest Point (Perigee): ~363,300 km
• Farthest Point (Apogee): ~405,500 km

Last verified on 01-04-2026