Explanation

• First Polio Vaccine Introduced: 1955
• Developer: Dr. Jonas Salk
• Type: Inactivated Polio Vaccine (IPV)
• Oral Polio Vaccine (OPV): 1961
• Developer of OPV: Dr. Albert Sabin

Last verified on 20-07-2026

Explanation

• Malaria is caused by the parasite Plasmodium.
• It is transmitted to humans through the bite of an infected female Anopheles mosquito.
• Malaria is a parasitic disease.
• It mainly affects the liver and red blood cells.
• Common symptoms include fever, chills, headache, and sweating.

Last verified on 11-07-2026

Explanation

• Saturn is the second-largest planet in the solar system.
• Ganymede (Moon of Jupiter) is the largest satellite in the solar system.

Planets and Natural Satellites:

1. Mercury: 0
2. Venus: 0
3. Earth: 1 (Moon)
4. Mars: 2 (Deimos, Phobos)
5. Jupiter: 95
6. Saturn: 274
7. Uranus: 27

Last verified on 02-05-2026

Explanation

• Mercury is the only elemental metal that at room temperature is Liquid.
• Mercury (Hg) is the only metal that remains liquid at room temperature (about 25°C).

Additional information:

• Chemical Symbol: Hg
• Atomic Number: 80
• Melting Point: −38.83°C
• Boiling Point: 356.73°C

Last verified on 20-07-2026

Explanation

• Most of the energy produced by the Sun is due to Nuclear Fusion (Fusion of Hydrogen).
• In the Sun's core, hydrogen nuclei fuse to form helium, releasing a huge amount of energy.
• This energy is emitted as light and heat.
• Nuclear fusion has powered the Sun for about 4.6 billion years.

Last verified on 20-07-2026

Explanation

• The age of the Universe is approximately 13.8 billion years.

Additional information:

• Age of the Earth: ≈ 4.54 billion years
• Age of the Solar System: ≈ 4.6 billion years
• Age of the Milky Way: ≈ 13.6 billion years
• Big Bang: Occurred about 13.8 billion years ago

Last verified on 20-07-2026

Explanation

• The age of a tree is determined by its Rings (Number of Annual Rings).
• Each annual ring generally represents one year of growth.
• Counting the rings on the trunk helps determine the tree's age.
• The study of tree rings is called Dendrochronology.

Last verified on 20-07-2026

Explanation

• Carbon Dating is one of the methods to calculate the age of fossils. It is based on the principle of Radioactivity.
• Radioactive isotope: Carbon-14 (¹⁴C)
• Half-life: 5,730 years
• Developed by: Willard Libby
• Introduced: 1949
• Dating range: Up to 50,000 years

Last verified on 20-07-2026

Explanation

• The SI unit of sound intensity is watt per square meter (W/m²).
• Sound intensity is the amount of sound power passing through a unit area.
• It shows how strong or weak a sound wave is at a particular point.
• Sound intensity decreases as the distance from the source increases.
• Decibel (dB) is used to measure sound intensity level, not the actual intensity

Last verified on 20-07-2026

Explanation

• Pakistan's standard household electricity supply is 220–240 V AC at 50 Hz.
• The frequency of alternating current (AC) is 50 cycles per second (50 Hz).
• This standard is used for homes, schools, offices, and most electrical appliances in Pakistan.

Last verified on 19-07-2026