Explanation

• The reciprocal of bulk modulus is called compressibility.
• Formula: Compressibility = 1 / Bulk Modulus
• Bulk modulus measures resistance to compression.
• Symbol: β = 1/K.
• SI unit: Pa⁻¹ (per Pascal).
• Higher bulk modulus means lower compressibility

Last updated 18-07-2026 by NA

Explanation

• Bones do not secrete hormones,
• Hormones are produced by glands in the endocrine system.
• The parathyroid gland secretes parathyroid hormone.
• It regulates calcium levels in the blood and bones.

Addition information 

• Functions performed by bones in the human body:
• Support: Provides a rigid framework for soft tissues.
• Protection: Shields vital organs like the brain, heart, and lungs.

Last updated 18-07-2026 by NA

Explanation

• The instrument used to measure temperature is called a thermometer.
• A thermometer shows how hot or cold an object or place is.

Additional information:

• Barometer measures air pressure.
• Hygrometer measures humidity (moisture in air).

Last verified on 16-06-2026

Explanation

• The SI unit of electric current is Ampere (A).
• Electric current measures the flow of electric charge.
• Defined using the elementary charge (e = 1.602176634 × 10⁻¹⁹ C).
• Named after: André-Marie Ampère (scientist).
• 1 Ampere = 1 Coulomb per second (1 A = 1 C/s).

Last verified on 08-06-2026

Explanation

• Kilometers per second: ≈ 300,000 km/s
• Speed in vacuum: 299,792,458 m/s
• Approximate value: 3 × 10⁸ m/s
• Symbol: c
• Distance traveled in 1 second: About 300,000 km
• Light from the Sun takes about 8 minutes 20 seconds to reach the Earth.

Last verified on 16-05-2026

Explanation

• The speed of sound is maximum in solids 
• Because particles are tightly packed, allowing faster vibration transfer.
• In iron, sound travels around 5120 m/s,
• Much faster than in air (343 m/s) or water (1482 m/s).

Last updated 17 july 2026 by NA

Explanation

• Surface tension prevents water from penetrating waterproof materials.

Additional information 

• Friction: Force that opposes the motion between two surfaces in contact.
• Adhesion: Attraction between molecules of different substances.
• Gravity: Force that pulls objects toward the Earth

Last updated by NA on 16-07-2026

Explanation

• An endemic disease is a disease that is constantly present in a specific population or geographic area.
• Examples:
• Malaria
• Chickenpox
• Dengue Fever

Additional information 

• Epidemic: A sudden, unexpected spike in cases within a specific community or region.
• Pandemic: An epidemic that has spread globally, covering multiple countries or continents.

Last updated by NA on 16-07-2026

Explanation

• Meteorology is the science of the atmosphere and weather patterns.

Additional information 

• Climatology: weather patterns and climate changes over time.
• Oceanography:  oceans, marine ecosystems, currents, and the seabed.
• Geology: Earth's solid rocks, minerals, and the physical history of its structure.
• Astronomy: celestial objects, space, and the physical universe beyond Earth

Last updated by NA on 16-07-2026

Explanation

• 24-karat (24K) gold is considered the "best"
• Purity: 99.9% pure gold.
• Color: Rich, deep, bright yellow.

Additional information

• 22K Gold: 91.7% pure gold. It is mixed with harder metals like silver or copper.
• 18K Gold: 75% pure gold. It is highly durable and excellent for diamond settings 
• Carat is the unit of measurement for the physical weight of diamonds/gold.

Last updated by NA on 16-07-2026