scientist, discoveries & inventions MCQ section 4 MCQ Questions & Answers Detailed Explanation

Answer: (d)

Lactometer is used to check the purity of milk. The specific gravity of milk does not give a conclusive indication of its composition since milk contains a variety of substances that are either heavier or lighter than water.

The device works on the principle of Archimedes’s principle that a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced.

Answer: (b)

The Analytical Engine was a proposed mechanical general-purpose computer designed by English mathematician Charles Babbage. It was first described in 1837 as the successor to Babbage's Difference Engine, a design for a mechanical computer.

The Analytical Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.

Answer: (b)

French physicist Henri Becquerel discovered radioactivity by accident in 1896 when a piece of uranium left in a dark desk drawer made an image on photographic plates.

The husband and wife team of Pierre and Marie Curie became interested in Becquerel’s discovery. While experimenting with their own uranium-containing ore, they came up with the term “radioactivity” to describe the spontaneous emissions that they studied.

Answer: (d)

Answer: (d)

Dr Hans von Ohain and Sir Frank Whittle are both recognized as being the co-inventors of the jet engine. Each worked separately and knew nothing of the other’s work. Hans von Ohain is considered the designer of the first operational turbojet engine.

Frank Whittle was the first to register a patent for the turbojet engine in 1930. Hans von Ohain was granted a patent for his turbojet engine in 1936. However, Hans von Ohain’s jet was the first to fly in 1939. Frank Whittle’s jet first flew in 1941.

Answer: (d)

Meteorology is the scientific study of the atmosphere or weather. Meteorological phenomena are observable weather events which are explained by the science of meteorology. Those events are bound by the variables that exist in Earth’s atmosphere; temperature, air pressure, water vapor, etc.