99 Fun Facts About Electrical Engineering

Which physicist quit a Cologne teaching post when an 1827 treatise on circuits met a cold reception?

Georg Ohm resigned his post at a school in Cologne after the cold reception. Recognition came from abroad, when Britain's Royal Society awarded him its Copley Medal in 1841.

Alessandro Volta built the first battery while disputing which fellow Italian's theory of 'animal electricity' in frogs' legs?

Luigi Galvani believed the twitching came from electricity inside the animal. Volta argued that it came from two different metals touching, and proved his point by stacking metal discs into a battery.

The Leyden jar, invented independently in 1745-46, was the original form of which component?

The capacitor began as an accident: an experimenter in Leiden, holding a jar of water charged through a wire, touched the wire and took a powerful shock, proof that the jar had been storing charge.

Michael Faraday's spinning copper disc of 1831 is called the first electric what?

A generator: the turning disc gave a small but continuous current. Ten years earlier Faraday had built the reverse, a simple motor that turned current into motion.

The SI unit of inductance is named after which American scientist?

Joseph Henry was beaten into print on induction by Michael Faraday, then became the first to notice self-induction while working with his electromagnets. He later ran the Smithsonian as its first secretary.

A farad is defined as one of which unit per volt?

Coulomb is the unit: one farad stores one coulomb of charge for every volt applied. That makes the farad enormous, so everyday parts are rated in millionths or even trillionths of one.

Who set out the two basic circuit laws as a 21-year-old student?

Gustav Kirchhoff set them out in 1845 while studying at Königsberg. He later turned to light, and with Robert Bunsen used a spectroscope to discover two new elements, caesium and rubidium.

Who rewrote Maxwell's equations into the compact four-equation vector form used today?

Oliver Heaviside left school at 16 and had no further formal education. He worked as a telegraph operator, studied Maxwell's theory on his own, and cut its sprawling set of equations down to the four taught today.

A radar set is said to have melted a candy bar in Percy Spencer's pocket, inspiring which kitchen appliance?

The microwave oven followed once Spencer tested the effect on purpose, holding popcorn kernels near the radar equipment until they popped. Raytheon's first model, sold in 1947, stood about six feet tall.

Nikola Tesla's alternating-current motor and polyphase patents were licensed in 1888 by which company?

Westinghouse Electric paid in cash, stock and a royalty on every horsepower sold. When the company later ran short of money, Tesla agreed to give up the royalty so that it could keep backing his motor.

The tesla was adopted as the SI unit of what in 1960?

Magnetic flux density took Nikola Tesla's name in 1960, a late honour: he had died nearly penniless in 1943 after years of moving between New York hotels and leaving the bills unpaid.

Which tycoon backed Nikola Tesla's Wardenclyffe Tower, then refused to fund a larger design?

J. P. Morgan had put up $150,000 for a transatlantic wireless station. When Tesla enlarged the plan to send power as well as messages, Morgan declined to pay more, and the tower was abandoned without ever working.

In 1890 Thomas Edison's allies made sure a rival's alternating-current generator powered the first of which devices?

The electric chair was the point: if the state killed with a rival's alternating current, the public might think it too dangerous for the home. The same campaign had stray animals electrocuted in public.

In 1896 the new power station at Niagara Falls began sending alternating current over long-distance lines to which city?

Buffalo was lit by Niagara's power that November. The feat is often counted as the unofficial end of the war of the currents, with alternating current the winner over direct.

Which country runs both 50 Hz and 60 Hz mains grids?

Japan has used both since the 1890s, when Tokyo bought 50 Hz generators from Germany and Osaka bought 60 Hz machines from the United States. The split hampered efforts to share power after the 2011 earthquake.

Who invented the first vacuum tube, the two-element valve, in 1904?

John Ambrose Fleming built it on the 'Edison effect', a one-way current that Thomas Edison had noticed inside his light bulbs some twenty years earlier. Fleming put it to work detecting radio signals.

What did Lee de Forest call his three-element amplifying tube, the first practical electronic amplifier?

The Audion worked, yet de Forest had little idea how or why, and his early tubes behaved erratically. It took other engineers several more years to turn it into a dependable amplifier.

Which three Bell Labs physicists shared the 1956 Nobel Prize for the transistor?

Bardeen, Brattain and Shockley shared the prize, though the first two built the first transistor without the third. Furious at being left out, Shockley devised a sturdier design of his own within weeks.

Before silicon took over, which semiconductor crystal was used in the first transistor in 1947?

Germanium worked, but transistors made from it could not take much heat. Silicon, which keeps going at higher temperatures, began to replace it once the first silicon transistors were made in 1954.

Who invented the first working MOSFET at Bell Labs in 1959?

Mohamed Atalla and Dawon Kahng made an old idea work: Lilienfeld and Heil had patented field-effect devices in the 1920s and 1930s, but neither is known to have built one that functioned.

Jack Kilby demonstrated the first working integrated circuit in 1958 while newly employed by which company?

Texas Instruments had hired Kilby only a couple of months before its summer shutdown, so he had no holiday to take. Alone in the deserted lab, he thought up the chip and had one working by September.

Which 'Mayor of Silicon Valley' devised the first practical silicon integrated circuit and co-founded Fairchild and Intel?

Robert Noyce's design laid the connections onto the silicon itself, where Jack Kilby's rival chip of a few months earlier had needed them wired by hand. That made his the version that could be mass-produced.

How many engineers left Shockley Semiconductor Laboratory in 1957 to found Fairchild Semiconductor?

Eight left, and 'the traitorous eight' is said to have been Shockley's own label for them. They had asked his backer to replace him as manager, were refused, and walked out together to start a rival firm.

In its 1975 revision, Moore's law says the transistor count on an integrated circuit doubles roughly how often?

Every two years was Moore's slower revision of the yearly doubling he had first forecast a decade earlier. Chipmakers then planned their research around the rule, which helped make it a self-fulfilling prophecy.

The IEEE was formed in 1963 by merging the IRE with which older body?

The American Institute of Electrical Engineers was the elder by 28 years. But the Institute of Radio Engineers grew faster as electronics boomed, and by the late 1950s it was the larger of the two.

Which company, in 1922, made Edith Clarke the first woman employed as an electrical engineer in the United States?

General Electric had first hired her as a human 'computer', since she could not find work as an engineer despite a master's degree from MIT. She later became the country's first female professor of electrical engineering.

Superconductivity was discovered in 1911 by Heike Kamerlingh Onnes while cooling which metal?

Mercury lost all resistance a few degrees above absolute zero, a test possible only because Onnes had been first to liquefy helium three years earlier. He named the effect 'supraconductivity'.

Samuel Hunter Christie invented which resistance-measuring circuit in 1833?

The Wheatstone bridge bears the wrong man's name: Christie's description went largely unnoticed for a decade, until Charles Wheatstone brought it to wide notice in 1843.

The decibel grew out of measuring transmission loss in which industry?

Telephony engineers coined the decibel in 1928 to replace the dry label 'transmission unit'. The bel itself, named after Alexander Graham Bell, proved too large for everyday use, so a tenth of it became the standard.

The hertz honours Heinrich Hertz, who in the 1880s became the first to prove the existence of what?

Radio waves struck Hertz as a laboratory curiosity: asked what his discovery was good for, he is said to have answered that it was 'of no use whatsoever'. He died at 36, before radio proved him wrong.

The watt, the SI unit of power, honours James Watt for improving which machine?

The Newcomen steam engine wasted most of its steam reheating a cylinder that was cooled on every stroke. Watt, asked to repair a model of one at Glasgow University, cured the fault with a separate condenser.

Since the 2019 SI revision, the ampere has been defined by fixing the exact value of what?

The elementary charge, the charge on a single proton, now fixes the ampere. The old definition imagined two infinitely long wires a metre apart in a vacuum, a set-up no laboratory could actually build.

Which Danish physicist showed in 1820 that an electric current deflects a compass needle?

Hans Christian Ørsted's finding reached Paris within months. André-Marie Ampère set to work on it at once and showed that two current-carrying wires attract or repel each other, the basis of electrodynamics.

Which Hollywood star co-patented a frequency-hopping radio system for guiding torpedoes in 1942?

Hedy Lamarr devised it with the composer George Antheil so that an enemy could not jam the guidance signal. The pair never made money from the patent, which expired before such systems came into use.

The ohm's symbol is which letter?

The uppercase omega has a mirror twin: turned upside down it once stood for the 'mho', which is 'ohm' spelled backwards, the old unit for how easily a current flows.

What was the Regency TR-1, introduced in 1954?

The first commercial transistor radio was built to show the public what the new component was good for, and it sold out. A small Japanese firm followed with its own set the next year and renamed itself Sony.

Which engineer co-invented the blue LED and shared the 2014 Nobel Prize in Physics for it?

Shuji Nakamura's blue LED filled a gap that had defeated the industry for three decades. Red and green ones already existed, and only with blue could LEDs be combined to make white light.

Henry Round, who first reported light from a crystal diode in 1907, was an engineer for which radio pioneer?

Marconi employed Round, who saw a carborundum crystal glow when current passed through it and sent a short note to a journal. The effect then stayed a curiosity until practical LEDs arrived in the 1960s.

Claude Shannon's 1937 MIT master's thesis showed that digital circuits could be designed using what?

Boolean algebra struck Shannon as the right tool while he looked after the switching circuits of an early analog computer in a part-time job. His write-up has been called possibly the most important master's thesis of the century.

Which effect lets a transformer pass power between two coils that never touch, provided the current keeps changing?

Electromagnetic induction happens only while a magnetic field is changing, so a steady direct current passes nothing to the second coil. That is why direct current was so hard to step up or down in voltage.

Which connection standard is named after a 10th-century king who united Denmark and Norway?

Bluetooth began as a code name: its engineers hoped to unite computers and phones as King Harald Bluetooth had united Scandinavia. Marketing was meant to find something better, but the name had already stuck.

Which weak form of magnetism, named by Michael Faraday, lets a strong enough magnet levitate a live frog?

Diamagnetism was first noticed in bismuth in 1778, but Faraday showed that it is a general property of matter. Physicists later made the point by floating a frog in a Dutch laboratory, which won them an Ig Nobel Prize.

The loss of which ship led to rules requiring ships to keep a radio operator on watch around the clock?

The Titanic's distress calls went unheard by a ship close by, the Californian, because its radio operator had gone off duty for the night. The rules that followed demanded a 24-hour watch.

William Gilbert's Latin 'electricus', used in 1600 for materials that attract when rubbed, comes from the Greek word for which substance?

Amber, 'elektron' in Greek, attracts light objects when it is rubbed, and Gilbert gave its name to every material that did the same. The English noun 'electricity' followed from Thomas Browne in the 1640s.

Which message opened Samuel Morse's 1844 telegraph line?

What hath God wrought comes from the Book of Numbers. It was picked for Morse by Annie Ellsworth, the young daughter of the patent commissioner who had backed his invention.

Which eerie-sounding electronic instrument grew out of a Russian physicist's gas-measuring device in 1920?

The theremin is played without being touched: moving the hands near its two antennas changes the pitch and volume. Its inventor noticed the effect when his device whined as he moved, and later played it for Lenin.

Which lower Manhattan street gave Edison's 1882 central power station its name?

Pearl Street Station borrowed its business model from the gas companies it meant to replace. Edison ran his wires under the streets to nearby customers and billed each one by the amount of current used.

Who led the team behind Britain's Chain Home radar network?

Robert Watson-Watt's stations could see raids forming up over France, so in the Battle of Britain RAF commanders had time to put their scarce fighters in the right place instead of guessing.

The 1858 transatlantic telegraph cable linked Ireland with which island?

Newfoundland's Trinity Bay received the 1858 cable from Valentia Island in Ireland; Queen Victoria and President Buchanan exchanged messages in August before the cable failed within weeks.

AC/DC took its name from a label the Young brothers' sister spotted on which household appliance?

A sewing machine belonging to Margaret Young carried the letters on its power adapter, marking it as able to run on alternating or direct current.

Which insect jammed a relay in Harvard's Mark II computer in 1947, the first recorded computer bug?

A moth was pulled from the relay and taped into the team's logbook, a page the Smithsonian keeps in its museum collection in Washington.

Which carbonized plant gave Thomas Edison a light bulb filament that lasted more than 1,200 hours?

Bamboo outlasted the cotton and linen thread, wood splints and coiled paper that Edison had listed in his 1879 lamp patent.

Which British comedian earned a master's degree in electrical engineering at The Queen's College, Oxford?

Rowan Atkinson dreamed up Mr. Bean while studying for that degree at The Queen's College, Oxford, having taken a first degree in the subject at Newcastle.

Martin Cooper made the first public handheld cellular call in 1973 while working for which company?

Motorola's Cooper stood on a Manhattan sidewalk with the DynaTAC prototype and rang his counterpart at rival Bell Labs.

Why can a bird perch on a single overhead power line without getting an electric shock?

Both feet share one potential, so nothing pushes a current through the bird; stretching a wing to a second wire would open a path straight through its body.

Thomas Edison's colleague Edward Johnson hand-wired 80 bulbs in 1882 to create the first electric what?

Christmas tree lights debuted at Johnson's New York home in three patriotic colours, each bulb the size of a walnut and made specially for him.

Rickenbacker's A-22, widely seen as the first successful electric guitar, is nicknamed after which kitchen item?

A frying pan is what the cast-aluminium lap steel's circular body and long neck resembled when it went on sale in the early 1930s.

Which first did the battery-powered Belgian racer La Jamais Contente claim for road vehicles in 1899?

Topping 100 km/h at Achères, near Paris, gave driver Camille Jenatzy the land speed record in a bullet-shaped car with two motors on its rear axle.

In Back to the Future, Doc Brown's DeLorean needs 1.21 of which unit to travel through time?

Gigawatts are spelled jigowatts in the film's script, matching the soft g heard on screen. The DeLorean's 1.21 of them is roughly 1.6 million horsepower.

Thomas Edison was called the Wizard of which New Jersey community, home to his laboratory from 1876?

Menlo Park was a failed real estate development, named after a California town, when Edison moved his home and laboratory there.

Which 18th-century experimenter first labelled the two kinds of electric charge positive and negative?

Benjamin Franklin's labels replaced the older terms vitreous and resinous, and he also gave the science the words charge and battery.

Theodore Maiman fired the first working laser in 1960 using a synthetic crystal of which gemstone?

Ruby was a material rival laser teams had written off as unworkable; Maiman's pink crystal, pumped by a xenon flash lamp, proved them wrong on a $50,000 budget.

Which city's 1893 world's fair, lit by Nikola Tesla's polyphase system, showcased alternating current?

Chicago's fair was the first to be all-electric, and the lighting contract went to the bidder who undercut a rival direct-current offer by 70 cents a lamp.

Which precious metal conducts electricity best, though its cost keeps copper in household wiring?

Silver has the highest electrical conductivity of any metal, and it also tops the table for thermal conductivity and reflectivity.

Which metal, with the highest melting point of all, became the standard filament in light bulbs?

Tungsten melts only at 3,422 °C, so a filament of it can glow white-hot without failing; the same toughness puts it in X-ray tubes and welding electrodes.

Which unreactive gas, almost 1% of the air, fills incandescent light bulbs to protect the filament?

Argon shields the white-hot filament from oxidation and is by far the cheapest noble gas, being the third most abundant gas in Earth's atmosphere.

Under the international IEC colour code, which two colours mark a cable's protective earth wire?

Green and yellow stripes may be used only for the protective conductor, so the standard bans either colour from every other striped combination.

Which Hewlett-Packard engineer created the Apple I computer and co-founded Apple in 1976?

Steve Wozniak offered the design to Hewlett-Packard first and was turned down five times before he and Steve Jobs sold it themselves.

Which crystal, vibrating 32,768 times a second, keeps time in nearly all battery-powered watches?

Quartz is cut into a tiny tuning fork whose 32,768 beats a second, a power of two, let a simple counter halve them down to one pulse per second.

Which inventor conceived electronic television at 14, inspired by the back-and-forth lines of a plowed field?

Philo Farnsworth worked out his image dissector in 1921 and sent his first picture, a simple straight line, between two rooms of a San Francisco lab in 1927.

Which satellite, launched in July 1962, relayed the first live television pictures across the Atlantic?

Telstar 1 could link the two continents for only about 30 minutes of each two-and-a-half-hour orbit, while it was passing over the ocean.

Which power source did Bell Labs researchers Daryl Chapin, Calvin Fuller and Gerald Pearson invent in 1954?

The solar cell grew out of a hunt for something to power remote equipment in the humid tropics, where dry batteries failed; by 1958 it was flying on the Vanguard 1 satellite.

Which 1945 computer, built at the University of Pennsylvania, contained about 18,000 vacuum tubes?

ENIAC was built to calculate artillery firing tables for the US Army, and its panels were held together by around five million hand-soldered joints.

Intel's 4004, the first commercial microprocessor, began as a Busicom order for chips for which product?

A calculator was all Busicom wanted when it ordered a set of custom chips, but Intel engineer Marcian Hoff proposed a simpler design built around a single-chip processor.

The first visible-light LED, demonstrated by Nick Holonyak in 1962, glowed which colour?

Red was the only visible colour early LEDs could manage; Holonyak got it by growing a gallium arsenide phosphide crystal that shifted the glow out of the infrared.

Which English inventor's Gateshead house was the first in the world fitted with working light bulbs?

Joseph Swan first showed his carbon lamp to a Newcastle audience in 1878, and by 1881 his bulbs were lighting London's Savoy Theatre.

Charles Kao shared the 2009 Nobel Prize in Physics for showing light could carry data through fibres of what?

Glass fibres were thought too lossy to be useful until Kao showed that removable impurities, not the material itself, were swallowing the light.

Which metal, the least dense of all, is in the rechargeable batteries honoured by the 2019 chemistry Nobel?

Lithium is light enough to float on water, and three researchers who turned it into a rechargeable battery shared the 2019 prize.

Georges Claude lit the 1910 Paris Motor Show with two 12-metre glowing tubes of which gas?

Neon was a by-product of Claude's air-liquefaction business, and an associate quickly spotted a new trade in signage and advertising.

Which engineer, nicknamed the Wizard of Schenectady, built much of the theory of alternating-current systems?

Charles Steinmetz stood just 1.22 metres tall and was also called the Forger of Thunderbolts; his work on hysteresis let engineers design far better motors.

Which American inventor of the superheterodyne receiver went on to develop wide-band FM in the 1930s?

Edwin Armstrong began his first major invention, the regenerative circuit, while still an undergraduate at Columbia, and his FM cut the static that plagued AM.

The siemens, the unit of conductance, was once known by which name, the resistance unit spelled backwards?

Mho was Lord Kelvin's suggestion in 1883, a nod to conductance being the reciprocal of resistance; the siemens became an official SI unit in 1971.

Electrical engineers write the imaginary unit with which letter instead of the mathematician's i?

The letter j is used because i already stands for electric current, a clash that would muddle every AC circuit equation.

Electric current is written as I because of a French phrase describing the current's what?

Intensity, from intensité du courant, gave Ampère his symbol in 1820, yet at least one journal went on writing C for current until 1896.

Which French mathematician's series lets engineers split any repeating signal into simple sines and cosines?

Joseph Fourier introduced the series in 1807 to work out how heat spreads through a metal plate, long before anyone had an electrical signal to analyse.

Which telegraph engineer's 1883 theorem reduces any linear circuit to one voltage source and one resistance?

Léon Thévenin worked for France's posts and telegraphs service, and independently reached a result Hermann von Helmholtz had derived 30 years before him.

An AC supply's rated 230 volts is which kind of average, the DC value that delivers the same power?

Root mean square values understate the swing: a 230-volt sinusoid actually travels peak to peak across about 2.8 times the quoted figure.

Which unit of energy, equal to 3.6 megajoules, do household electricity meters and bills count?

Kilowatt-hour meters count energy rather than power: one unit is what a one-kilowatt heater gets through in an hour.

Phillip Smith's circular chart of 1939 helps RF engineers match which property of transmission lines?

Impedance matching is the chart's main job, and it might have carried another name: Tōsaku Mizuhashi proposed the same diagram independently in 1937.

Which electric-arc researcher was the first woman elected to Britain's Institution of Electrical Engineers?

Hertha Ayrton had just become the first woman to read her own paper to the institution, which admitted no other woman as a member until 1958.

Which Northumberland house, built for a Victorian arms magnate, was the first lit by hydroelectric power?

Cragside drew its power from lakes dammed in the grounds, which also ran a hydraulic lift, an early dishwasher and a rotisserie.

The first long-distance three-phase power line ran 175 km from Lauffen in 1891 to which German city?

Frankfurt's exhibition settled a quarrel over which kind of current to adopt: after the trial, three-phase became the norm for power networks worldwide.

Which American patented the detachable electric plug in 1904, after devising the pull-chain light socket?

Harvey Hubbell went on to patent a three-bladed plug with a ground prong in 1916, a design Australia later adopted as its national standard.

Harold Black sketched the negative-feedback amplifier on his copy of The New York Times while riding what?

A ferry across the Hudson River carried Black to work, and he later began an autobiography under the working title Before the Ferry Docked.

The EBR-I reactor lit four light bulbs in 1951 with some of the first nuclear electricity, in which US state?

Idaho's EBR-I was also the world's first breeder reactor, a design meant to produce more nuclear fuel than it burns.

Pioneering station KDKA began in 1920 by broadcasting presidential election results from which US city?

Pittsburgh listeners heard Warren Harding beat James Cox that night, while the station was still using the amateur call sign 8ZZ.

Which country, home to the steaming Devil's Valley, built the world's first geothermal power plant in 1911?

Italy's Larderello field had already lit a handful of light bulbs in a 1904 trial run by Prince Piero Ginori Conti.

The 2003 blackout that hit 55 million North Americans spread after what failed in a utility control room?

The alarm software had a bug that left FirstEnergy's operators unaware that overloaded lines were failing, so no one shifted the load in time.

Nikola Tesla was born in 1856 in the village of Smiljan, which lies in which present-day country?

Croatia was part of the Austrian Empire when Tesla was born there, the son of an Eastern Orthodox priest who served at the village church.