Machine-translated by Google. Questions are authored in English.
Top

Inventions Questions and Answers

21.

the name of the CalTech seismologist who invented the scale used to measure the magnitude of earthquakes is?

Answer: A

Charles Richter.

He devised the scale at the California Institute of Technology in 1935 with Beno Gutenberg. It is logarithmic: each whole number is a tenfold increase in wave amplitude and about thirty-two times the energy.

Please log in or register to report this question.

23.

First regenerative circuit was invented and patented in 1914 by

Answer: D

Edwin Armstrong invented it.

He patented the regenerative circuit in 1914 while an undergraduate, feeding part of a valve's output back to its input so that the same valve amplified a signal many times over. It made long-distance radio reception possible.

Please log in or register to report this question.

24.

Who prepared the first effective vaccine against polio?

Answer: D

Jonas Salk invented the polio vaccine.

His injected vaccine of 1955 used killed virus, and he refused to patent it, asking who could patent the sun. Albert Sabin's oral vaccine, using live attenuated virus, followed and is the one used in mass campaigns.

Please log in or register to report this question.

26.

Atomic theory was devised by

Answer: A

John Dalton devised it.

His atomic theory of 1808 held that elements consist of indivisible atoms, that all atoms of an element are identical in mass, and that compounds form in fixed whole-number ratios - which explained the laws of conservation of mass and of definite and multiple proportions at once.

Please log in or register to report this question.

27.

The cholera bacillus was discovered by

Answer: A

Robert Koch discovered it.

He identified Vibrio cholerae in Calcutta in 1884, having traced it from Egypt to India, and showed it spread through contaminated water. He had earlier found the anthrax and tuberculosis bacilli.

Please log in or register to report this question.

28.

The velocity of light was first measured by

Answer: A

Ole Romer first measured it.

The Danish astronomer noticed in 1676 that the eclipses of Jupiter's moon Io ran late when the earth was farther from Jupiter, and inferred that light takes time to cross the distance. His figure was about 220,000 km/s - low, but the first demonstration that light has a finite speed.

Please log in or register to report this question.

30.

What Enrico Fermi invented?

Answer: D

Enrico Fermi built the first nuclear reactor.

Chicago Pile-1, a stack of graphite blocks and uranium, went critical on 2 December 1942 under the stands of the university's squash court - the first self-sustaining nuclear chain reaction. The message sent was that the Italian navigator had landed in the new world.

Please log in or register to report this question.

Loading…
Tags: Inventions Questions and Answers || Inventions MCQ Questions and Answers || Inventions GK Questions and Answers || Inventions GK MCQ Questions || Inventions Multiple Choice Questions and Answers || Inventions GK || GK on Inventions || General Awareness / General Knowledge (GK) Questions and Answers || General Awareness / General Knowledge (GK) MCQ Questions and Answers || General Awareness / General Knowledge (GK) GK Questions and Answers || GK on General Awareness / General Knowledge (GK)