The first thermionic valve was invented by
Answer: C
J.A. Fleming invented it.
He patented the thermionic valve, or diode, in 1904, using the Edison effect - the flow of current from a hot filament to a plate in a vacuum - to rectify radio signals. Lee de Forest added a third electrode two years later.
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The first practical photographic process, the daguerreotype, was developed by ________.
Answer: C
Correct answer: Louis Daguerre
Daguerre announced his process in 1839, producing a sharp image on a silvered copper plate. It had no negative, so each picture was unique, and Talbot’s rival calotype, which did use a negative, is the ancestor of later photography.
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Who Invented Microwave Oven ?
Answer: C
Percy Spencer invented it.
An engineer at Raytheon, he noticed in 1945 that a chocolate bar in his pocket had melted while he stood near an active magnetron. He tried popcorn next, then an egg, which exploded. Raytheon sold the first Radarange in 1947.
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Who discovered Insulin
Answer: D
F.G. Banting discovered insulin.
With Charles Best at Toronto in 1921 he extracted it from dog pancreas and showed that it controlled diabetes. He shared the 1923 Nobel Prize with J.J.R. Macleod and gave half his share to Best. Alexander Fleming discovered penicillin.
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Who invented the safety pin in 1849 ?
Answer: D
Correct answer: Walter Hunt
Walter Hunt patented the safety pin in 1849, reportedly designing it in a few hours to settle a debt, and sold the rights for four hundred dollars. Its coiled spring and guarded clasp are essentially unchanged today.
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Who Invented Traffic Signal ?
Answer: D
Garrett Augustus Morgan invented it.
The African-American inventor patented a three-position traffic signal in 1923, adding a warning interval between stop and go so that traffic could clear the junction. He sold the patent to General Electric for $40,000. He also invented a smoke hood used by firemen.
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Who invented the first successful vulcanisation process for rubber ?
Answer: C
Correct answer: Charles Goodyear
Charles Goodyear discovered in 1839 that heating rubber with sulphur made it stable across a wide range of temperatures. The tyre company bearing his name was founded decades after his death and had no connection with him.
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the first solid state integrated circuit was demonstrated In which decade?
Answer: A
It was demonstrated in the 1950s.
Jack Kilby at Texas Instruments built the first working integrated circuit in September 1958, on a sliver of germanium. Robert Noyce at Fairchild produced a silicon version months later, and it was his planar design that the industry adopted.
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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.
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The first practical mechanical sewing machine was patented by ________.
Answer: A
Correct answer: Elias Howe
Elias Howe patented his lockstitch sewing machine in 1846, using a needle with the eye at the point. Isaac Singer built a more commercially successful machine soon after, and the resulting patent dispute was settled by a pooling arrangement.
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