Inventions — Set 5

Correct Answer: A. Richard Trevithick

• **Richard Trevithick** = Richard Trevithick built the world's first steam-powered railway locomotive in 1804, hauling 10 tonnes of iron and 70 men along 16 km of tramway at Merthyr Tydfil, Wales. • **1804** — Trevithick's locomotive used high-pressure steam (which Watt had considered dangerous), making a compact and powerful engine possible; George Stephenson later refined the design for the Stockton–Darlington Railway (1825). • 💡 Wrong-option analysis: George Stephenson: built the famous Rocket locomotive (1829) and engineered the first public passenger railway, but Trevithick built the first steam locomotive 25 years earlier; Robert Fulton: built the first commercially successful steamboat; James Watt: improved the stationary steam engine but opposed high-pressure steam and never built a locomotive.

Correct Answer: D. Robert Jarvik

• **Robert Jarvik** = Robert Jarvik designed the Jarvik-7 artificial heart, which was first permanently implanted in patient Barney Clark by surgeon William DeVries on December 1, 1982, keeping Clark alive for 112 days. • **1982** — The Jarvik-7 was powered by an external pneumatic compressor; it was the first permanent artificial heart ever used in a human, bridging patients to heart transplant. • 💡 Wrong-option analysis: Michael DeBakey: pioneered cardiovascular surgery and developed the heart pump used during bypass operations; Paul Winchell: a ventriloquist who designed an early artificial heart prototype but it was never used clinically; Christiaan Barnard: performed the world's first successful human heart transplant in 1967 using a donor heart, not an artificial one.

Correct Answer: C. Rene Laennec

• **Rene Laennec** = René Laennec invented the stethoscope in 1816 in Paris; finding it immodest to place his ear on a patient's chest, he rolled paper into a tube and discovered it transmitted heart sounds far more clearly. • **1816** — Laennec's first stethoscope was a simple hollow wooden tube; modern binaural (two-earpiece) stethoscopes with flexible tubing were developed by the 1850s and remain essential diagnostic tools. • 💡 Wrong-option analysis: Claude Bernard: pioneered experimental medicine and discovered the role of the liver in glycogen metabolism; Louis Pasteur: developed germ theory, pasteurisation, and early vaccines; Joseph Lister: pioneered antiseptic surgery using carbolic acid.

Correct Answer: C. Jonas Salk

• **Jonas Salk** = Jonas Salk developed the first successful polio vaccine using killed (inactivated) poliovirus in 1952–1953; large-scale trials in 1954 confirmed its safety and effectiveness, and it was declared safe on April 12, 1955. • **1955** — In the first year of wide distribution, the vaccine reduced polio cases in the USA by over 90%; Salk refused to patent the vaccine so it could be produced cheaply and distributed globally. • 💡 Wrong-option analysis: Alexander Fleming: discovered penicillin (the first antibiotic) in 1928; Albert Sabin: developed the oral live attenuated polio vaccine (OPV) in the late 1950s — a different, later vaccine using live weakened virus; Louis Pasteur: developed vaccines for cholera, anthrax, and rabies in the 19th century.

Correct Answer: D. David Edward Hughes

• **David Edward Hughes** = David Edward Hughes invented the carbon microphone in 1878, using loosely packed carbon granules whose electrical resistance varies with the pressure of sound waves, producing a much clearer and stronger signal than earlier designs. • **1878** — Hughes's carbon microphone dramatically improved the intelligibility of voice in early telephone systems; a version of it remained in telephone handsets for over a century. • 💡 Wrong-option analysis: Emile Berliner: invented the gramophone flat disc record in 1887 and also independently developed a carbon microphone variation; Thomas Edison: developed a competing carbon button microphone for use in his telephone, but Hughes's device was first; Alexander Graham Bell: invented the telephone but used a liquid transmitter, not a carbon microphone.

Correct Answer: B. Carl von Linde

• **Carl von Linde** = Carl von Linde developed a reliable mechanical refrigeration process in 1876 using compressed liquid ammonia as the refrigerant, making industrial and eventually domestic refrigeration practical and commercially viable. • **1876** — Linde's system was the first to use a continuously cycling compressor-condenser-evaporator system — the same thermodynamic cycle used in modern refrigerators and air conditioners. • 💡 Wrong-option analysis: Fred Wolf: produced the first domestic electric refrigerator (the Domelre) in 1913, building on Linde's refrigeration technology; William Cullen: demonstrated the first artificial refrigeration (using diethyl ether evaporation) in 1756 but did not build a practical machine; Oliver Evans: designed a vapour-compression refrigeration concept in 1805 but never built it.

Correct Answer: C. Robert Watson-Watt

• **Robert Watson-Watt** = Robert Watson-Watt developed the first practical radar (Radio Detection And Ranging) system in 1935 for Britain, creating the Chain Home network of ground-based radar stations that detected incoming enemy aircraft during World War II. • **1935** — Watson-Watt's system could detect aircraft at ranges of up to 200 km; the Chain Home network, operational by 1939, was decisive in the Battle of Britain by giving the Royal Air Force advance warning of Luftwaffe raids. • 💡 Wrong-option analysis: Heinrich Hertz: proved the existence of radio waves experimentally in 1887 — the theoretical basis for radar — but died in 1894 before radar was developed; Luis Alvarez: made important wartime radar improvements (microwave radar) but Watson-Watt built the first operational system; Guglielmo Marconi: pioneered radio communication but did not develop a radar system.

Correct Answer: C. Shane Chen

• **Shane Chen** = Shane Chen invented and patented the self-balancing personal transporter commonly known as the hoverboard in 2013, using gyroscopes and tilt sensors to keep the platform level while allowing the rider to steer by shifting body weight. • **2013** — Chen filed the original patent under the name 'Hovertrax'; the device uses dual electric hub motors and a microprocessor to maintain balance dynamically. • 💡 Wrong-option analysis: Steve Jobs: co-founded Apple and revolutionised personal computing and smartphones; Elon Musk: founded SpaceX and Tesla but did not invent the hoverboard; Dean Kamen: invented the Segway two-wheeled self-balancing personal transporter in 2001, which uses similar gyroscopic technology on a larger, standing platform.

Correct Answer: B. John Logie Baird

• **John Logie Baird** = John Logie Baird demonstrated the world's first working television system on January 26, 1926 in London, transmitting moving greyscale images using a mechanical rotating Nipkow disc scanning system. • **1926** — Baird's first demonstration transmitted 12.5 frames per second at 30 lines of resolution; he later demonstrated colour and stereoscopic TV; the BBC used his mechanical system for broadcasts from 1929 to 1937. • 💡 Wrong-option analysis: Vladimir Zworykin: developed the iconoscope (electronic camera tube) and kinescope (picture tube), pioneering all-electronic television; Philo Farnsworth: invented the first fully electronic television system (1927), which eventually replaced Baird's mechanical system; Paul Nipkow: patented the rotating scanning disc in 1884 — the key component in Baird's system — but never built a complete television.

Correct Answer: C. The US Department of Defense

• **The US Department of Defense** = The GPS was developed by the US Department of Defense beginning in 1973 under the NAVSTAR programme, using a constellation of satellites to provide precise location, navigation, and timing anywhere on Earth. • **1983** — The full 24-satellite constellation was declared operational in 1993; the system was opened for civilian use after Korean Air Lines Flight 007 was shot down in 1983, later made free for all in 2000. • 💡 Wrong-option analysis: The Soviet Space Agency: operated the parallel GLONASS satellite navigation system; The United Nations: has no role in operating GPS satellites; The European Space Agency: operates the Galileo navigation system, a separate European alternative to GPS.