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

Answer: (c)

Answer: (d)

Answer: (d)

Louis Pasteur is traditionally considered as the progenitor of modern immunology because of his studies in the late nineteenth century that popularized the germ theory of disease, and that introduced the hope that all infectious diseases could be prevented as well as treated by vaccination.

He developed immunization methods for chicken cholera and anthrax in animals and for human rabies.

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: (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: (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.