Explanation

Antoine Henri Becquerel was an engineer, physicist, Nobel laureate,

First person to discover evidence of radioactivity.

 He belonged to France.

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

• 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

• 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

• Blue light has the shortest wavelength.
• In the visible spectrum, wavelength decreases from red to violet.

Additional information:

• Red light rays have the lowest frequency and highest wavelength value.

Last verified on 10-06-2026