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

Answer: (d)

Answer: (d)

Answer: (c)

When Card David Anderson discovered a new particle with a mass between that of the electron and proton, he named it 'mesoton' in a 1933 publication in the Physical Review.

However, on the advice of Professor R.A. Millikan, he changed the name to ‘mesotron’ although he (Anderson) did not agree with it.

Homi Jehangir Bhabha then sent a short paper to Nature journal in February 1939 in which he proposed the name meson. The name given by Bhabha has remained to this day and is used for a class of elementary particles.

Answer: (d)

A videotape is a recording of images and sounds onto magnetic tape as opposed to film stock used in filmmaking or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram.

Charles P. Ginsburg invented the videotape. He worked for Ampex and was inspired by the reel-to-reel machines used for recording sound.

Answer: (b)

Gunpowder was the first chemical explosive and the only one known until the invention of nitrocellulose, nitroglycerin, smokeless powder, and TNT in the second half of the 19th century.

Prior to the invention of gunpowder, many incendiary and burning devices had been used, including Greek fire. Roger Bacon invented gunpowder.

Answer: (c)

There are two ways in which scientists quantify the size of earthquakes: magnitude and intensity.

Magnitude measures the energy released at the source of the earthquake; Intensity measures the strength of shaking produced by the earthquake at a certain location. The Richter Scale is used for measuring the magnitude of earthquakes.

The magnitude value is proportional to the logarithm of the amplitude of the strongest wave during an earthquake. The mercalli scale is used to measure the intensity of earthquakes. The intensity of a quake differs greatly from place to place.

It depends upon such factors as the distance from the epicentre, the design and quality of construction of local buildings, and the type of surface beneath the buildings.