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

Answer: (c)

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.

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)

Answer: (d)

In 1800, Alessandro Volta, an Italian physicist, invented the first true battery, which came to be known as the voltaic pile.

The voltaic pile consisted of pairs of copper and zinc discs piled on top of each other, separated by a layer of cloth or cardboard soaked in brine (i.e., the electrolyte).

Answer: (d)

The oral polio vaccine (OPV) was developed in 1961 by Albert Sabin. Also called “trivalent oral polio vaccine” or “Sabin vaccine”, OPV consists of a mixture of live, attenuated (weakened) poliovirus strains of all three poliovirus types.

OPV produces antibodies in the blood to all three types of poliovirus. In the event of infection, these antibodies protect against paralysis by preventing the spread of wild poliovirus to the nervous system.