Explanation

• If an object absorbs all seven colors of light (i.e., all the wavelengths of visible light), it appears black.
• This is because no light is being reflected, and our eyes perceive the absence of light as black.
• When an object reflects all the component colors of light, it appears white.

Last verified on 18-03-2026

Explanation

• Coal is a non-renewable resource because it takes millions of years to form and cannot be replenished quickly.
• Pakistan uses coal for energy production, especially in power plants like the Thar coal project.

Non-renewable energy sources:

• Oil
  
• Nuclear energy
• Petroleum
• Natural gas & coal

Renewable sources of energy:

• Solar energy
• Wind energy
• Hydroelectric power
• Biomass energy
• Geothermal energy
• Tidal energy

Last verified on 11-02-2026

Explanation

NOTE: Hydrogen is the lightest gas, but Helium is generally preferred. However, since "Helium" is not listed among your choices, the correct answer from the provided options is Hydrogen

• Helium is the lightest safe gas commonly used for:
• Party balloons
• Advertisement balloons
• Weather balloons

Common MCQ Confusion

• Hydrogen is actually the lightest gas overall, but it is highly flammable and can catch fire.
• Helium is slightly heavier than hydrogen but is non-flammable and safe, so it is used in balloons.

Last verified on 18-03-2026

Explanation

• Animal cells do not have chloroplasts, as they are not capable of photosynthesis.
• Animal cells also do not have a cell wall, unlike plant cells and some other organisms.

The components of an animal cell:

• Cell Membrane
• Cytoplasm
• Small Vacuole
• Nucleus
• Chromosomes

Last verified on 18-03-2026

Explanation

• Anthropology is the scientific study of human beings.
• It covers all humans across time, including past, present, and future societies.
• It studies culture, evolution, behavior, and social life of humans everywhere.

Last verified on 18-03-2026

Explanation

• Phosphorus (P), Potassium (K), and Nitrogen (N) are three essential macronutrients for plant growth.
• It is also referred to as "NPK".
• They play critical roles in various plant processes, including photosynthesis, root development, and cell growth.

Last verified on 17-03-2026

Explanation

• A sphygmomanometer is a medical device used to measure blood pressure.
• It consists of an inflatable cuff and a pressure gauge.

Last verified on 17-03-2026

Explanation

• Sand is primarily composed of silicon dioxide (SiO₂).
• It is a chemical compound made of silicon and oxygen atoms in a 1:2 ratio.
• SiO₂ is found in quartz, glass, and sand naturally.
• It is hard, chemically stable, and insoluble in water.

Last verified on 16-03-2026

Explanation

• 1 meter = 3.2808 feet exactly.

Additional information:

• 1 kilometer = 3280.8 feet
• 1 centimeter = 0.032808 feet
• 1 inch = 0.083333 feet
• 1 mile = 5280 feet
• 1 yard = 3 feet

Last verified on 16-03-2026

Explanation

• Copper is a chemical element with the symbol Cu and atomic number 29. 
• It is a soft, malleable, and ductile metal with a reddish-orange color.

The some major elements with their symbols:

• Hydrogen - H
• Sodium - Na
• Carbon - C
• Nitrogen - N
• Oxygen - O
• Fluorine - F
• Chlorine - Cl
• Potassium - K
• Helium - He
• Neon - Ne
• Calcium - Ca
• Sulphur - S
• Phosphorus - P
• Aluminium - Al
• Magnesium - Mg
• Iron - Fe

Last verified on 16-03-2026