Inventions Questions and Answers

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.

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.

Answer: A

Har Gobind Khorana did.

He and his team synthesised a complete functional gene, the yeast alanine transfer RNA gene, in 1970 - the first artificial gene. He had already shared the 1968 Nobel Prize in medicine for work on the genetic code.

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.

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.

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.

Answer: C

Ferdinand von Zeppelin invented the rigid airship.

His LZ-1 flew in 1900, with a rigid aluminium frame covered in fabric holding separate gas cells. Zeppelins carried passengers across the Atlantic until the Hindenburg burned at Lakehurst in 1937.

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.

Answer: C

Igor Sikorsky invented the helicopter.

The Russian-born American engineer flew the VS-300 in 1939, the first practical single-rotor helicopter with a tail rotor to counter torque - the configuration almost every helicopter has used since.

Answer: C

It was Dr Pepper.

Charles Alderton, a pharmacist at Morrison's Old Corner Drug Store in Waco, Texas, mixed it in 1885 - a year before Coca-Cola, making it the oldest major soft drink in the United States.