Explanation

• Alexander Fleming discovered Penicillin
• At St. Mary's Hospital in London
• In September 1928.
• First true antibiotic used to treat bacterial infections.
• First patient treated was Albert Alexander, a 43-year-old policeman, on 12 February 1941

Last updated by NA on 23-April-2026

Explanation

Surface area = 4πr², Volume = 4/3πr³.  

Surface area is just derivative of volume w.r.t r.

2πr is circumference of a circle, not volume at all.

Last verified on 07-06-2026

Explanation

• Battery is a device that converts chemical energy into electrical energy.
• Batteries work by using a galvanic cell.
• It is an electrochemical device made up of two electrodes and an electrolyte solution.

Last verified on 16-03-2026

Explanation

• Nicolaus Copernicus is called the Father of Modern Astronomy.
• He introduced the heliocentric theory in 1543.
• This theory stated that the Sun is at the center of the solar system.
• His ideas changed the old belief that Earth is the center.

Additional information:

• Galileo Galilei, a later figure, is often called the "father of observational astronomy".

Last verified on 01-06-2026

Explanation

• The Earth’s circumference at the equator is about 40,075 km (24,901 miles).
• Measured through the poles, it is slightly smaller: 40,008 km (24,860 miles).
• The difference is due to the equatorial bulge caused by Earth's rotation.
• Diameter: ~12,756 km (7,926 miles).
• Age of Earth: ~4.453 billion years.

Last verified on 31-03-2026

Explanation

• The largest planet in our solar system is Jupiter.
• 5th planet
• 79 known moons (Maximum number of moons)
• The Great Red Spot is a prominent feature
• Giant planet and the fastest-rotating planet 
• Rotates approximately once every 10 hours.
• Age is about 4.603 billion years.

Additional information

• Mercury is the smallest planet of the solar system.

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Last updated by NA on 25-April-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

• The first metal discovered and used by humans was Copper.
• It was found in native form (pure metal) in nature.
• Early humans used it for tools and ornaments before iron age.
• This period is known as the Copper Age (Chalcolithic Age).

Last verified on 30-05-2026

Explanation

• Anemometer is a scientific instrument used to measure wind speed (velocity).
• It is mainly used in meteorology and weather forecasting.
• It helps in studying storms, cyclones, and air pressure changes.
• Common types include cup, vane, and hot-wire anemometers.

Additional Information:

• A hygrometer is an instrument used to measure humidity.
• A salinometer is used to measure the salinity
• A bolometer is used to measure the power of incident electromagnetic radiation
• A barometer is used to measure air pressure in certain environment.

Last verified on 30-05-2026

Explanation

• A lactometer is used to measure the purity and density (thickness) of milk.
• It checks if milk has been adulterated with water by measuring specific gravity.
• Works on the principle of buoyancy.
• Pure milk specific gravity: 1.028–1.032 at 15°C

Last verified on 16-03-2026