Explanation

• Humidity is the amount of water vapor present in the air.
  • It affects weather, climate, and comfort levels.
  • High humidity can make the air feel hotter, low humidity feels drier.
  • Measured using a hygrometer.
  • Important in agriculture, meteorology, and human health.

Last verified on 05-02-2026

Explanation

• Sunlight is a good source of vitamin D.
• When our skin is exposed to sunlight, it produces vitamin D, 
• It is essential for bone health, immune function, and the regulation of calcium levels in the blood.
• Deficiency of Vitamin D results in Rickets.

Explanation

• Sound waves are mechanical waves and need a medium to travel.
  • They travel fastest in solids, slower in liquids, and slowest in gases.
  • Solid particles are closely packed, allowing rapid vibration transfer.

Last verified on 04-02-2026

Explanation

Bees must collect nectar from approximately 2 million flowers to make 1 pound of honey.

This immense effort requires bees to fly roughly 55,000 to 90,000 miles

A honey bee visits 50 to 100 flowers during a single,, dedicated collection trip.

Production Context: It takes approximately 556 worker bees to gather enough nectar for 1 pound of honey. 

Explanation

• The first process in a petroleum refinery is Distillation.
• It is also known as Fractional Distillation.
• This process separates crude oil into various fractions or types of hydrocarbons, based on their boiling points and molecular weights.

Additional information:

The processes in a petroleum refinery:

1. Cracking
2. Reforming
3. Isomerization
4. Hydrotreating
5. Hydrocracking
6. Catalytic Cracking
7. Alkylation

Last verified on 22-01-2026

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

A myopic defect can be corrected by using a concave lens of suitable power. 

Myopia is a disease related to Eye

Myopia is a common vision condition in which we can see objects near to us clearly, but objects farther away are blurry.

Myopia means دورکی نظر کی کمزوری

Explanation

Studies show that it takes an average of 8 minutes and 20 seconds for sunlight to move from the sun to the earth.

Sunlight moves at the speed of light.

You can see that the distance of the sun from the earth = 149.6 x 106 km.

Photons emitted from the surface of the sun need to traverse the vacuum of the universe to reach our eyes.

Explanation

Radioactivity was discovered by Henri Becquerel in 1896.

They discovered radioactivity proving that the uranium emitted radiation without an external source of energy such as the Sun

Marie Curie with her husband Pierre Curie, coined the term radioactivity.

In 1903, Henry Becquerel shared the Nobel Prize for Physics with Pierre and Marie Curie

Ernest Rutherford did many experiments studying the properties of radioactive decay (alpha, beta, and gamma)

Explanation

Thomas Alva Edison was an American inventor.

He developed many devices: 

• Electric power generation 
•  Mass communication
•  Sound recording
• Motion pictures.