Explanation

• The first metal discovered and used by humans was Copper.
• It was found in native form (pure metal) in nature.
• Early humans used it for tools and ornaments before iron age.
• This period is known as the Copper Age (Chalcolithic Age).

Last verified on 30-05-2026

Explanation

• Anemometer is a scientific instrument used to measure wind speed (velocity).
• It is mainly used in meteorology and weather forecasting.
• It helps in studying storms, cyclones, and air pressure changes.
• Common types include cup, vane, and hot-wire anemometers.

Additional Information:

• A hygrometer is an instrument used to measure humidity.
• A salinometer is used to measure the salinity
• A bolometer is used to measure the power of incident electromagnetic radiation
• A barometer is used to measure air pressure in certain environment.

Last verified on 30-05-2026

Explanation

• A lactometer is used to measure the purity and density (thickness) of milk.
• It checks if milk has been adulterated with water by measuring specific gravity.
• Works on the principle of buoyancy.
• Pure milk specific gravity: 1.028–1.032 at 15°C

Last verified on 16-03-2026

Explanation

• Crossing over occurs in Pachytene stage of Prophase I.
• Homologous chromosomes are fully paired and exchange genetic material at this stage.
• This leads to new gene combinations.

Last verified on 20-05-2026

Explanation

• Vitamin D is essential for healthy bones.
• Its deficiency leads to Rickets in children and Osteomalacia in adults.
• Sunlight is the best natural source of Vitamin D.

Additional information:

Deficiency effects:

• Bone pain
• Weak bones
• Skeletal deformities

Other Vitamin Deficiencies:

• Vitamin A: Night blindness
• Vitamin C: Scurvy
• Vitamin B7 (Biotin): Hair fall

Last verified on 17-01-2026

Explanation

• Metals allow electricity to pass through them easily.
• Among all metals, silver has the highest electrical conductivity.
• Copper and gold are also very good conductors.
• Silver is widely used in high-precision electrical applications.
• Copper is commonly used in wiring due to cost-effectiveness.

Last verified on 16-05-2026

Explanation

• Planet: Uranus
• Type: Ice Giant
• Temperature: Around −224°C (coldest recorded)
• Position from Sun: 7th planet
• Composition: Hydrogen, helium, methane
• Discovered: William Herschel in 1781

Last verified on 16-05-2026

Explanation

• Isobars are atoms of different elements.
• They have same mass number but different atomic number.
• They show different chemical properties but same nuclear mass.
• Example: Argon-40 and Calcium-40 both have mass number 40 but different atomic numbers.

Last verified on 07-05-2026

Explanation

• Vitamin A deficiency → Night blindness (Nyctalopia)
• Vitamin A is important for vision and immune function.

Additional information:

• Vitamin K is essential for blood clotting.
• Vitamin D helps in calcium absorption and bone mineralization.
• Vitamin B1 supports nerve function and energy metabolism.

Last verified on 01-02-2026

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