Explanation

• Mass and Length are base quantities in SI units.
• Length SI Unit: meter (m)
• Mass SI Unit: kilogram (kg)

Additional information:

Base Quantities in SI System:

• Time (second)
• Electric current (ampere)
• Temperature (kelvin)

Last verified on 16-06-2026

Explanation

• The audible range of a normal human ear is 20 Hz to 20,000 Hz (20 kHz).
• Below 20 Hz: Infrasound
• Above 20 kHz: Ultrasound
• Unit of frequency: Hertz (Hz)

Last verified on 23-06-2026

Explanation

• Light Year is the distance that light can travel in one year.
• The distance light travels in one year is known as light year.
• 1 light year is equal to 9.5 x 10¹²km.

Last verified on 30-03-2026

Explanation

• Solvent extraction is controlled by the Distribution Law (Nernst Distribution Law).
• It describes how a solute distributes between two immiscible liquids.
• At equilibrium, the concentration ratio remains constant.
• This law governs equilibrium in extraction processes.

Last verified on 18-06-2026

Explanation

• Calcium chloride (CaCl₂) is used as a drying agent in a desiccator.
• It absorbs moisture from the air.
• It keeps substances dry and free from water vapor.
• Desiccators are used in laboratories for drying chemicals.
• CaCl₂ is highly hygroscopic.

Last verified 18-06-2026

Explanation

• Chile saltpeter is the common name for sodium nitrate (NaNO₃).
• It is found naturally in Chile and Peru.
• It is used in fertilizers and explosives.

Last verified on 18-06-2026

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

Explanation

When white light passes through a prism, it splits into 7 colors, forming a spectrum known as a rainbow:

1. Red
2. Orange
3. Yellow
4. Green
5. Blue
6. Indigo
7. Violet

The separation of visible light into its different colours is known as dispersion.

Last verified on 08-06-2026

Explanation

• Mitochondria are called the powerhouse of the cell.
• Because they produce Adenosine Triphosphate (ATP).
• ATP is the energy currency of the cell.
• ATP provides energy for different cellular activities such as movement, growth, and transport.
• Energy is produced through aerobic cellular respiration using oxygen and الغذائی molecules.
• They are found in the cytoplasm of most eukaryotic cells.
• Richard Altmann first described mitochondria in 1890.

Main Parts of a Cell:

1. Cell membrane → Outer protective layer
2. Nucleus → Controls cell activities
3. Cytoplasm → Jelly-like material between membrane and nucleus

Last verified on 09-05-2026

Explanation

• An electric generator is a device that converts mechanical energy into usable electrical energy.
• This process is based on the principle of electromagnetic induction.
• Discovered in 1831 by British scientist Michael Faraday.

Last verified on 27-04-2026