Explanation

• A parameter is a value used to describe or define a system, model, or function.
• It usually remains constant for a particular situation.
• Example: In (y = mx + c), m and c can be parameters.

Last updated: NA on 26-09-2026

Explanation

• Earth is called the Blue Planet.
• About 71% of Earth's surface is covered by water.
• Water makes Earth appear blue from space.
• Earth is the third planet from the Sun.
• Earth’s natural satellite is the Moon

Last updated: NA on 26-09-2026

Explanation

• Wavelength is the distance between successive wave crests.
• SI unit: Meter (m)
• Commonly measured in: Nanometers (nm) and Angstroms (Å)
• 1 nm = 10⁻⁹ m
• 1 Å = 10⁻¹⁰ m = 0.1 nm
• Visible light: Approximately 400–700 nm

Last updated: 20-09-2026 by NA

Explanation

• Astrology studies the supposed influence of stars and planets on human affairs.
• Origin: Ancient Mesopotamia (modern Iraq).
• Developed by: Sumerians and Babylonians.
• Period: Around the 3rd–2nd millennia BCE.

Explanation

• Ice is less dense than water, so it floats.
• Archimedes’ Principle explains the buoyant force acting on floating ice.
• The buoyant force acts upward against gravity.
• Formula: FB = p Vg
• Key point: An object floats when buoyant force = its weight.