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

• Total bones in adult human body = 206
• At birth = 270–300 bones (fuse to become 206)

The total bones of our body can be divided into:

• Axial skeleton = 80 bones
• Appendicular skeleton = 126 bones

Additional information:

• Newborn baby has 300 bones
• Longest bone = Femur
• Shortest bone = Stapes
• Bones in human skull = 22

Last verified on 30-03-2026

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

• Inventor: Thomas Alva Edison.
• Country: United States.
• Practical incandescent bulb: 1879.
• Other contributions: Electric power, sound recording, motion pictures.
• Famous invention: Phonograph.

Last verified on 03-09-2026

Explanation

• Paramecium contains two nuclei: a macronucleus and a micronucleus.
• The macronucleus controls daily metabolic and cellular activities.
• The micronucleus is responsible for reproduction and genetic exchange.
• Paramecium is a single-celled protozoan found in freshwater.
• It belongs to the phylum Ciliophora.

Last verified on 27-07-2026

Explanation

• The magnitude of an earthquake is measured by the Richter scale.
• It measures the energy released by an earthquake.
• The Richter scale was developed in 1935 by Charles F. Richter.
• It is used in seismology (the study of earthquakes).

Last verified on 30-06-2026

Explanation

• The hardest substance in the world is diamond.
• Its hardness is due to the strong covalent bonding between its carbon atoms.
• This making it the most resistant to scratching.

Additional information:

• Category: Native minerals
• Cleavage: 111 (perfect in four directions)
• Crystal class: Hexoctahedral (m3m); H-M symbol: (4/m 3 2/m)
• Crystal habit: Octahedral
• Crystal system: Cubic
• Dana classification: 1.3.6.1
• Density: 3.5–3.53 g/cm3 3500–3530 kg/m3

Last verified on 07-06-2026

Explanation

• The usual gases used for lifting airships are hydrogen and helium.
• Hydrogen is the lightest known gas and thus has great lifting capacity,
• Helium is not as buoyant but is far safer than hydrogen because it does not burn.

Last verified on 01-04-2026

Explanation

• Meteorology is the scientific study of the atmosphere, especially weather and climate.
• It involves forecasting and understanding atmospheric phenomena.
• Meteorology is a branch of the atmospheric sciences.
• Metrology is the scientific study of measurement.

Last verified on 03-04-2026

Explanation

• Gamma rays have the highest penetrating power among these particles.
• Due to their lack of mass and charge.
• It allowing them to pass through most materials.

Additional information:

• Alpha radiation has the lowest penetrating power.

Last verified on 12-04-2026