Radar Trivia
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48 free Radar trivia questions with answers — technology quiz, new questions added Aug 2026.
Radar is the wartime secret that now opens supermarket doors, catches speeders and tells you whether to carry an umbrella. This quiz covers the technology from Heinrich Hertz's bounced radio waves to over-the-horizon arrays and stealth aircraft. The easy questions ask what the acronym stands for, who coined it, which effect lets radar read speed, what a police radar gun does and why weather radars glow red. From there it moves into the invention story: Hülsmeyer's telemobiloscope, the death-ray rumour that led Watson-Watt and Wilkins to the Daventry Experiment, the Chain Home stations that helped win the Battle of Britain, and the ten-centimetre magnetron that Randall and Boot built in Birmingham. The harder end is for history and engineering readers: the Tizard Mission's deed box, the MIT Radiation Laboratory, the SCR-270 blip at Opana Point, Window over Hamburg, the Bruneval raid, the Soviet Redut sets, the first radar echoes from the Moon and Venus, Ufimtsev's diffraction paper that shaped the F-117, the Russian Woodpecker, the Arecibo dish and the Bell Labs origins of the radar altimeter, plus the letter-band code names and the range equation's inverse fourth power. Every answer was checked against encyclopaedia entries on radar, its history and its applications, and the supporting sentence is stored with each question. If you enjoy this one, try our World War II, inventions and aviation quizzes next.
30 of 48 questions with answers and explanations. Play the quiz
Q 01What does the acronym RADAR stand for?
Radio detection and ranging
RADAR stands for radio detection and ranging, a term coined in 1940; it has since become an ordinary lowercase noun.
Q 02Which organisation coined the term RADAR in 1940?
The US Navy
The US Navy coined RADAR in 1940 as a cover term; Britain had been calling the same technology RDF, for radio direction finding.
Q 03Which German physicist showed in 1886 that radio waves reflect off solid objects?
Heinrich Hertz
Heinrich Hertz, who first proved the electromagnetic waves Maxwell predicted, showed in his 1886-88 experiments that radio waves reflect from metal surfaces.
Q 04Which German inventor patented the 'telemobiloscope' in 1904 to detect ships in fog?
Christian Hülsmeyer
Christian Hülsmeyer patented his telemobiloscope in 1904; it rang a bell when a ship came within range but could not measure distance, and the German navy declined it.
Q 05Which Russian physicist noted in 1897 that a passing ship disturbed radio signals?
Alexander Popov
Alexander Popov, testing ship-to-ship radio in 1897, noted that a passing vessel disturbed the signal and remarked it might detect objects, but took it no further.
Q 06Which Scottish engineer led the British team that demonstrated pulsed radar in 1935?
Robert Watson-Watt
Robert Watson-Watt, who had earlier used radio to locate thunderstorms for airmen, led the team whose pulsed radar tracked aircraft from Orfordness in 1935.
Q 07What rumoured German weapon prompted the enquiry that led Britain to radar?
A radio death ray
Arnold Wilkins showed the death ray was impossible but suggested radio detection instead.
Q 08Whose shortwave transmitter was borrowed for the Daventry Experiment of 26 February 1935?
The BBC's
The BBC's Empire shortwave transmitter at Daventry supplied the signal; a Handley Page Heyford bomber flew through its beam while Wilkins's receiver in a nearby field picked up echoes.
Q 09What did Watson-Watt reportedly exclaim after the Daventry test succeeded?
'Britain has become an island again!'
Watson-Watt is reported to have said 'Britain has become an island again!' after the Daventry echoes; £12,300 of funding followed within days.
Q 10What was the codename of Britain's ring of coastal early-warning radar stations?
Chain Home
Chain Home, officially the AMES Type 1, was the world's first early-warning radar network, built by the RAF before and during the Second World War.
Q 11Where in Suffolk did Watson-Watt's team develop the coastal radar stations from 1936?
Bawdsey Manor
Bawdsey Manor, bought by the Air Ministry in 1936, became the Bawdsey Research Station; by 1940 its coastal stations ringed the whole UK coast including Northern Ireland.
Q 12Which 1940 air campaign did the coastal radar chain's early warning help the RAF to win?
Battle of Britain
Radar early warning let Fighter Command win the 1940 Battle of Britain by scrambling squadrons only when raids approached, the core of the 'Dowding system'.
Q 13Which two Birmingham physicists built the improved cavity magnetron in 1940?
John Randall and Harry Boot
Q 21Which ocean liner had parts of a French obstacle-detecting radio set installed in 1935?
Normandie
CSF fitted a 16 cm continuous-wave 'obstacle detector' built under Maurice Ponte to the liner Normandie in 1935; without pulses it sensed presence but not range.
Q 22What was the British codename for chaff, the strips of foil dropped to blind radar?
Window
Britain called chaff 'Window'; the Germans called it Düppel, and both sides held it back for months for fear the other would copy it.
Q 23Over which city was the foil countermeasure first used, during Operation Gomorrah in 1943?
Hamburg
Window was first dropped over Hamburg on the night of 24-25 July 1943; German searchlights and flak radars wandered helplessly among the false echoes.
John Randall and Harry Boot at the University of Birmingham ran their cavity magnetron on 21 February 1940; it gave about 400 watts at a 9.8 cm wavelength, unprecedented at the time.
Q 14What everyday appliance later used the cavity magnetron?
The microwave oven
The microwave oven runs on a cavity magnetron; a 1.1-kilowatt oven input yields about 700 watts of microwaves, around 65% efficiency.
Q 15Which 1940 British delegation carried a magnetron to the United States?
The Tizard Mission
The Tizard Mission of September 1940 carried a cavity magnetron to Washington; historian James Phinney Baxter called it 'the most valuable cargo ever brought to our shores'.
Q 16Which secret US lab, organised by Alfred Loomis, developed microwave radar from 1941 to 1945?
MIT Radiation Laboratory
The MIT Radiation Laboratory opened in Cambridge, Massachusetts in October 1940 after Loomis's Microwave Committee saw the British magnetron; by 1945 it employed nearly 4,000 people and had produced the SCR-584 gun-laying radar.
Q 17Where on Oahu did an SCR-270 radar spot the incoming Japanese planes in 1941?
Opana Point
The SCR-270 at Opana Point on Oahu's north shore picked up the raid at 7:02 am; Lieutenant Kermit Tyler assumed the blip was six B-17s due from California.
Q 18Which American demonstrated the first elementary pulsed radar in December 1934?
Robert M. Page
Robert M. Page of the Naval Research Laboratory transmitted the first pulsed radar signals in December 1934, detecting a small aircraft about a mile away over the Potomac.
Q 19Which German firm demonstrated a pulsed radar system in May 1935?
GEMA
GEMA, the firm set up to build Rudolf Kühnhold's sets, tested pulsed radar on the Baltic coast at Pelzerhaken in May 1935, weeks before Watson-Watt's Orfordness trials in June.
Q 20What did the Soviets call their first mass-produced radar, of which only 607 were built?
RUS-2 Redut
RUS-2 Redut, a metre-wave early-warning set, was the first Soviet radar built in quantity; work had slowed after pioneer P. K. Oshchepkov was sent to the gulag in 1937.
Q 24Chaff strips are cut to what fraction of the target radar's wavelength?
Half
Chaff is cut to half the radar's wavelength, so each strip acts as a resonant dipole that re-radiates the signal strongly.
Q 25Which German radar was seized and brought to Britain in Operation Biting in 1942?
Würzburg
The Bruneval raid of February 1942 carried off key parts of a Würzburg set; examining its receiver and transmitter showed British scientists how it could be jammed.
Q 26What phenomenon lets radar read a target's speed from a change in the returned frequency?
Doppler shift
Doppler weather radars can track wind and rotation inside storms.
Q 27Who invented the radar speed gun, working for the Automatic Signal Company in Connecticut?
Barker and Midlock
John L. Barker Sr. and Ben Midlock, who had built radar for the military in the Second World War, devised the radar speed gun at Automatic Signal Company in Norwalk, Connecticut.
Q 28Which nearby body was first detected by radar in 1946?
The Moon
Project Diana bounced radar off the Moon on 10 January 1946 from Fort Monmouth, New Jersey; later lunar radar mapped shadowed regions near its poles.
Q 29Which lab made the first unambiguous radar contact with Venus, on 10 March 1961?
Jet Propulsion Laboratory
The Jet Propulsion Laboratory's Goldstone antenna received Venus echoes on 10 March 1961; their timing gave a new, precise value for the astronomical unit.
Q 30How large was the Arecibo radar-radio dish that collapsed in 2020?
305 m
305 m (1,000 ft) across, the dish was completed in 1963 with a cable-mounted receiver and radar transmitters hanging 150 m above it.