Explanation

• Water has maximum density at 4°C.
• When Water is in its Solid form (Ice) below 0°C.

Last verified on 27-10-2026

Explanation

• The ozone layer protects the Earth from the sun.
• It is a part of the atmosphere that absorbs most of the harmful ultraviolet light from the sun.
• It sits in the stratosphere.
• It is about 9 to 18 miles above the Earth.
• It stops dangerous UV rays from hurting living things.

Last updated by NS on 14-8-2026

Explanation

• A Barometer is an instrument used to measure air (atmospheric) pressure.
• It helps in weather forecasting by measuring changes in atmospheric pressure.
• The mercury barometer is the oldest type of barometer.
• It was invented by Evangelista Torricelli in 1643.
• Barometers are widely used in meteorology and aviation.

Last verified on 09-07-2026

Explanation

• The SI unit of energy is the Joule (J).
• It is the unit of energy, work, and heat.

Additional information:

• 1 Joule (J) = 1 Newton × 1 meter
• Calorie – 1 cal = 4.184 J
• Kilowatt-hour (kWh) – 1 kWh = 3.6 × 10⁶ J
• Electronvolt (eV) – 1 eV ≈ 1.602 × 10⁻¹⁹ J
• Erg (CGS unit) – 1 erg = 10⁻⁷ J

Last verified on 17-01-2026

Explanation

• Neurons are the basic structural and functional units of the nervous system.
• They are specialized nerve cells.
• They transmit electrical and chemical signals.
• They control communication in the body.
• Brain, spinal cord, and nerves are made up of neurons.

Last verified on 08-06-2026

Explanation

• Gene Definition: Basic physical and functional unit of heredity
• Location: Found on chromosomes within DNA
• Function: Codes for proteins or RNA molecules that determine traits
• Types: Structural genes (proteins), regulatory genes (control expression)
• Inheritance: Passed from parents to offspring during reproduction

Last verified on 05-02-2026

Explanation

• The unit of pressure is N/m² (Newton per square meter).
• It is also called Pascal (Pa).
• Pressure means force applied per unit area.
• Higher force or smaller area increases pressure.

Last verified on 17-06-2026

Explanation

• MRI stands for Magnetic Resonance Imaging.
• It is a medical imaging technique.
• It uses strong magnetic fields and radio waves to create detailed images of organs and tissues.

Last verified on 03-09-2026

Explanation

• Main Cause: Freon / CFCs
• Effect: Breaks down O₃ molecules → more UV-B radiation
• Other Contributors: Halons, carbon tetrachloride
• Result: Skin cancer, cataracts, climate impact

• The Montreal Protocol (1987) aimed to reduce CFC emissions
• Ozone layer protects Earth from harmful ultraviolet rays

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