Explanation

• Sea water is denser than fresh water because it contains dissolved salts.
• The higher density produces a greater buoyant force, making objects float more easily.
• Fresh water contains much less dissolved salt, so its density is lower.
• This is explained by Archimedes' Principle.

Last verified on 03-07-2026

Explanation

• The Uncertainty Principle applies at the quantum level.
• It was proposed by Werner Heisenberg in 1927.
• It states that the exact position and momentum of a particle cannot be measured simultaneously with complete accuracy.

Last verified on 03-07-2026

Explanation

• When a moving car suddenly stops, the passenger's body tends to keep moving forward due to inertia of motion.
• This is explained by Newton's First Law of Motion.
• Only the car stops immediately; the passenger's body continues moving forward until restrained.
• Wearing a seat belt helps prevent injury by stopping the body safely.

Last verified on 03-07-2026

Explanation

• Weber (Wb) is the SI unit of magnetic flux.
• One Weber is equal to one volt-second (V·s).
• A magnetic flux density of 1 Weber per square metre (1 Wb/m²) is equal to 1 Tesla (T).
• Magnetic flux measures the total magnetic field passing through a surface.

Last verified on 03-07-2026

Explanation

• Tin (Sn) is not a semiconductor.
• Tin is a metal and a good conductor of electricity.
• Silicon (Si), Germanium (Ge), and Selenium (Se) are well-known semiconductors.
• Semiconductors have electrical conductivity between conductors and insulators.

Last verified on 03-07-2026

Explanation

• A geostationary satellite orbits the Earth at a speed that matches the Earth's rotation.
• It staying fixed above the same point on the Earth's surface.
• This allows it to maintain a constant position relative to the Earth.

Last verified on 03-07-2026

Explanation

• Sound cannot travel through a vacuum because there are no particles to carry sound vibrations.
• Sound needs a medium such as a solid, liquid, or gas to travel.
• Since space is nearly a vacuum, sound cannot be heard there.
• The speed of sound in a vacuum is 0 m/s.

Additional information:

• Infrasound: Below 20 Hz
• Audible sound: 20 Hz – 20,000 Hz (20 kHz)
• Ultrasound: Above 20 kHz
• Speed of sound in air: 343 m/s
• Speed of sound in water: 1,481 m/s

Last verified on 07-06-2026

Explanation

• The magnitude of an earthquake is measured by the Richter scale.
• It measures the energy released by an earthquake.
• The Richter scale was developed in 1935 by Charles F. Richter.
• It is used in seismology (the study of earthquakes).

Last verified on 30-06-2026

Explanation

🔹 1 BTU = 1055.06 Joules (approx.)

🔹 1 BTU = 252 calories (approx.)

🔹 1 Joule = 0.0009478 BTU

🔹 1 kWh = 3412 BTU, linking electrical energy to heat energy.

🔹 Commonly used in heating/cooling systems

🔹 Named after the British engineers who developed early thermal measurements

Last verified on 30-06-2026

Explanation

• Farad (F) is the SI unit of capacitance of a capacitor.
• Capacitance is the ability of a capacitor to store electric charge.
• One farad is equal to one coulomb of charge stored per one volt of potential difference.
• The unit is named after scientist Michael Faraday.

Additional information:

• Energy / Work → Joule (J)
• Electric Charge → Coulomb (C)
• Pressure → Pascal (Pa)
• Electric Current → Ampere (A)
• Power → Watt (W)
• Resistance → Ohm (Ω)
• Temperature → Kelvin (K)
• Torque → Newton metre (N·m)
• Velocity → metre per second (m/s)
• Acceleration → metre per second² (m/s²)

Last verified on 28-06-2026