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

• 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 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

Explanation

• In 1924, Louis de Broglie proposed that matter has both particle and wave properties.
• This concept is known as the De Broglie Hypothesis or Matter Wave Theory.
• It became one of the foundations of Quantum Mechanics.

Last verified on 19-07-2026

Explanation

• The Universe is continuously expanding.
• Age of the Universe: ≈13.8 billion years
• Big Bang: ≈13.8 billion years ago
• Hubble's discovery: 1929
• Cosmic Microwave Background discovered: 1965
• Expansion is accelerating due to dark energy.

Last verified on 19-07-2026

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

• 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