Explanation

• Pakistan produces a huge amount of its electricity from Hydropower.
• Major hydropower stations are located on the Indus River system.

Additional information:

Major Hydropower Dams:

• Tarbela Dam (Khyber Pakhtunkhwa)
• Mangla Dam (Azad Jammu & Kashmir)
• Ghazi-Barotha Hydropower Project
• Warsak Dam
• Neelum–Jhelum Hydropower Project

Major Sources of Electricity in Pakistan:

• Hydropower
• Natural Gas
• Coal
• Nuclear Energy
• Solar & Wind Energy

Last verified on 21-07-2026

Explanation

• The value 332 m/s is measured under standard atmospheric conditions.

Additional information:

• Speed of sound in air at 20°C ≈ 343 m/s.
• Speed of sound is faster in solids than liquids and gases.

Examples:

• Air: ~332 m/s (0°C)
• Water: ~1,480 m/s
• Steel: ~5,100 m/s

Last verified on 21-07-2026

Explanation

• The Mantle is the middle layer located between the crust and the core.
• It is the thickest layer of the Earth.
• It is made of hot, semi-solid rock.
• Thickness of Mantle: About 2,900 km
• Earth's Average Radius: About 6,371 km

Additional information:

• The Earth has three main layers: Crust, Mantle, and Core.
• Outermost layer: Crust
• Innermost layer: Core

Last verified on 21-07-2026

Explanation

• Venus is called the Morning Star and Evening Star.
• It is the second closest planet to the Sun.
• It is the brightest planet and the hottest planet in the Solar System.
• It has no natural moon (satellite).
• It is also known as the "Black Planet".

Last verified on 21-07-2026

Explanation

• An Astronomical Unit (AU) is the average distance between the Earth and the Sun.
• It is a standard unit used to measure distances within the Solar System.
• 1 AU = 149,597,870.7 km
• 1 AU = 92,955,807.3 miles
• Light travels 1 AU in: About 8 minutes 20 seconds

Last verified on 21-07-2026

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