scientist, discoveries & inventions MCQ section 1 MCQ Questions & Answers Detailed Explanation

Answer: (d)

The aneroid barometer is an instrument for measuring pressure as a method that does not involve liquid. Invented in 1844 by French scientist Lucien Vidi, it uses a small, flexible metal box called an aneroid cell, which is made from an alloy of beryllium and copper.

Answer: (c)

The distribution of energy in the spectrum of radiations of a hot body cannot be explained by applying the classical concepts of physics. Max Planck gave an explanation for this observation by his Quantum Theory of Radiation.

Answer: (a)

Radar is an object detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. In 1922 A. Hoyt Taylor and Leo C. Young, researchers working with the U.S. Navy invented Radar.

Answer: (c)

A eudiometer is a laboratory device that measures the change in volume of a gas mixture following a physical or chemical change. Applications of a eudiometer include the analysis of gases and the determination of volume differences in chemical reactions.

It is similar in structure to the meteorological barometer.

Answer: (d)

Lactometer is used for measuring the density (creaminess) of milk. It is essentially a hydrometer which is an instrument used to measure the specific gravity (or relative density) of liquids; that is, the ratio of the density of the liquid to the density of water.

Answer: (b)

King Camp Gillette, an American businessman, invented the best selling version of the safety razor in 1901. Several models were in existence before Gillette’s design.

Gillette’s innovation was the thin, inexpensive, disposable blade of stamped steel. Gillette is widely credited with inventing the so-called razor and blades business model.