Explanation

Explanation

• Smog is a combination of smoke and fog.
• The word smog is formed from smoke + fog.
• It is a type of air pollution that reduces visibility and can harm human health.
• Smog is commonly associated with vehicle emissions and industrial pollutants.

Last verified on 06-10-2026

Explanation

• The SI unit of power is the watt (W). 
• A watt is equal to one joule of work done per second. 
• Symbol: W
• Definition: 1 watt = 1 joule per second
• Named after: James Watt

Last verified on 05-10-2026

Explanation

• Cell biology  is a branch of biology that studies the structure, function, and behavior of cells.
• All living organisms are made of cells.
• Also cellular biology or cytology
  

Explanation

• Sericulture is the farming or rearing of silkworms for the production of silk.
• The most commonly cultivated silkworm is Bombyx mori.
• Silkworms feed mainly on mulberry leaves and produce silk fibers to form their cocoons.

Additional information:

• Apiculture: Rearing of honeybees for honey and other products.
• Agriculture: Cultivation of crops and raising of animals.
• Pisciculture: Farming or breeding of fish.

Last verified on 05-10-2026

Explanation

• Watt (W) is the SI unit of power, while kilowatt (kW) is also a unit of power.
• 1 kilowatt = 1,000 watts.
• Power indicates the rate at which energy is used or transferred.

Additional information:

• Kilowatt-hour (kWh) is a unit of electrical energy.

Last verified on 05-10-2026

Explanation

• The troposphere is the lowest layer of the atmosphere.
• Most weather phenomena occur in this layer.
• Clouds, rain, storms, and winds mainly occur here.
• It extends roughly 8–15 km above Earth’s surface.

• Mesosphere: About 50–85 km; most meteors burn up here.
• Ionosphere: Region with many charged particles; important for radio communication and auroras.
• Stratosphere: About 12–50 km; contains the ozone layer.

Explanation

• WBCs survive for about 13–20 days, depending on the type.
• WBCs are also called Leukocytes.
• They protect the body against infections.
• They are produced in the bone marrow.

Important Note: The 13–20 days lifespan is not applicable to all WBCs; their lifespan varies according to type.

Explanation

• Nitrous oxide, commonly known as laughing gas.
• It is a colorless, non-flammable gas used in medicine.
• Nitrous oxide (N₂O) causes temporary laughing and relaxation.

Additional information:

• Nitrous oxide was discovered by Joseph Priestley in 1772.

Last verified on 18-01-2026

Explanation

The least count of a Vernier caliper is 0.1 mm (or 0.01 cm).

It is the smallest measurement that can be accurately read using the instrument.

It is derived from the difference between one main scale reading and one Vernier scale reading.

It is commonly used to accurately measure outside diameters of shafts, thicknesses of various parts, diameters of holes or rings, internal dimensions of hollow jobs, and depths of holes or steps.