Explanation

• The number of spark plugs needed in a diesel engine is zero
• Diesel engines use compression ignition instead of a spark.
• Air is compressed until it is hot enough to ignite the fuel.
• Instead of spark plugs, they use glow plugs to warm the engine when cold

Explanation

• Main mineral in hemoglobin: Iron
• Chemical symbol: Fe
• Location: Red blood cells
• Main function: Oxygen transport throughout the body

Last verified on 12-10-2026

Explanation

• Vitamin K helps to make various proteins that are needed for blood clotting and the building of bones.
• Prothrombin is a vitamin K-dependent protein directly involved with blood clotting.

• Vitamin C may protect the body against the effects of pollution.
• It may also prevent blood clots and reduce bruising.

Last verified on 31-03-2026

Explanation

• Wilhelm Conrad Rontgen discovered X-rays
• He was discovered on 8 November 1895.
• He got the Nobel Prize in Physics in 1901.

Additional questions

• The penetrating power of X-rays depends on their frequency

Last updated 26-07-2026 by NA

Explanation

• Watt (W) is the SI unit of power, while kilowatt (kW) is also a unit of power.
• 1 kilowatt = 1,000 watts.
• Power indicates the rate at which energy is used or transferred.

Additional information:

• Kilowatt-hour (kWh) is a unit of electrical energy.

Last verified on 05-10-2026

Explanation

• Saturn is famous for its prominent and beautiful ring system.
• Its rings are made mainly of ice particles, dust, and rock fragments.

Additional information:

• It is the second-largest planet in the Solar System.
• It is often called the “Ringed Planet.”
• Famous moon: Titan
• Orbital period: About 29.5 Earth years
• It is the sixth planet from the Sun.

Last verified on 27-09-2026

Explanation

• Carbon dioxide (CO₂) is used in fire extinguishers.
• It extinguishes fire by displacing oxygen and cooling the burning material.
• CO₂ fire extinguishers are especially effective for electrical and flammable liquid fires.
• Carbon dioxide is a colorless and non-flammable gas.
• It leaves no residue after use.

Explanation

• Myopia (Nearsightedness) is an eye defect in which near objects are clear but distant objects appear blurred.
• It occurs when the image forms in front of the retina instead of on it.
• It is corrected by using a concave (diverging) lens.
• The concave lens helps to shift the image back onto the retina.

Last verified on 01-04-2026

Explanation

• 24-karat (24K) gold is considered the "best"
• Purity: 99.9% pure gold.
• Color: Rich, deep, bright yellow.

Additional information

• 22K Gold: 91.7% pure gold. It is mixed with harder metals like silver or copper.
• 18K Gold: 75% pure gold. It is highly durable and excellent for diamond settings 
• Carat is the unit of measurement for the physical weight of diamonds/gold.

Last updated by NA on 16-07-2026

Explanation

• Chemical Name: Acetic Acid (Ethanoic Acid)
• Chemical Formula: CH₃COOH
• Vinegar Concentration: 4–8% Acetic Acid
• Type of Acid: Weak Organic Acid
• Uses: Food seasoning, pickling, preservation, cleaning

Last verified on 10-07-2026