scientist, discoveries & inventions MCQ section 1 Practice Questions Answers Test with Solutions & More Shortcuts

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: (a)

The spectroheliograph is an instrument used in astronomy which captures a photographic image of the Sun at a single wavelength of light, a monochromatic image. The wavelength is usually chosen to coincide with an spectral wavelength of one of the chemical elements present in the Sun.

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.