50 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 50 questions with answers and explanations. Play the quiz
Q 01What does the acronym RADAR stand for?
Radio detection and ranging
The word has since become an anacronym, a plain noun with no capitals.
Q 02Which organisation coined the term RADAR in 1940?
The US Navy
Britain had been calling the technology RDF, for radio direction finding.
Q 03Which German physicist showed in 1886 that radio waves reflect off solid objects?
Heinrich Hertz
He was the first to prove the existence of the electromagnetic waves Maxwell's equations predicted.
Q 04Which German inventor patented the 'telemobiloscope' in 1904 to detect ships in fog?
Christian Hülsmeyer
It could sense a distant ship's presence but not measure its distance, and the military rejected it.
Q 05Which Russian physicist noted in 1897 that a passing ship disturbed radio signals?
Alexander Popov
He wrote that the effect might detect objects but did nothing more with it.
Q 06Which Scottish engineer led the British team that demonstrated pulsed radar in 1935?
Robert Watson-Watt
He had earlier used radio to warn airmen of thunderstorms and claimed descent from James Watt.
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
A Handley Page Heyford bomber flew over the field while a GPO receiver watched for echoes.
Q 09What did Watson-Watt reportedly exclaim after the Daventry test succeeded?
'Britain has become an island again!'
The Treasury released £12,300 within days for further development.
Q 10What was the codename of Britain's ring of coastal early-warning radar stations?
Chain Home
Officially the AMES Type 1, it was the world's first early-warning radar network.
Q 11Where in Suffolk did Watson-Watt's team develop the coastal radar stations from 1936?
Bawdsey Manor
By 1940 the stations stretched around 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
It formed part of the 'Dowding system' for coordinating fighter responses.
Q 13Which two Birmingham physicists built the improved cavity magnetron in 1940?
John Randall and Harry Boot
Their first example produced hundreds of watts at a 10 cm wavelength, an unprecedented feat.
Q 21What did the Soviets call their first mass-produced radar, of which only 607 were built?
RUS-2 Redut
Development slowed after its pioneer P. K. Oshchepkov was sent to the gulag.
Q 22Which ocean liner had parts of a French obstacle-detecting radio set installed in 1935?
Normandie
CSF's team under Maurice Ponte built it, though it used continuous waves rather than pulses.
Q 23What was the British codename for chaff, the strips of foil dropped to blind radar?
Window
The Germans called it Düppel; both sides hesitated to use it in case the other copied it.
Q 14What everyday appliance later used the cavity magnetron?
The microwave oven
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
Historian James Baxter called it 'the most valuable cargo ever brought to our shores'.
Q 16Where did 'Magnetron Number 12' spend the night before its 1940 voyage to America?
Under Edward Bowen's hotel bed
The documents travelled in a lockable metal deed box strapped to a taxi roof.
Q 17Which secret US lab, organised by Alfred Loomis, developed microwave radar from 1941 to 1945?
MIT Radiation Laboratory
Robert Page there refined radar with the monopulse technique in 1943.
Q 18Where on Oahu did an SCR-270 radar spot the incoming Japanese planes in 1941?
Opana Point
Lieutenant Kermit Tyler assumed the blip was six B-17s arriving from California.
Q 19Which American demonstrated the first elementary pulsed radar in December 1934?
Robert M. Page
He was working at the Naval Research Laboratory.
Q 20Which German firm demonstrated a pulsed radar system in May 1935?
GEMA
Rudolf Kühnhold's team beat Watson-Watt's British demonstration by a month.
Q 24Over which city was the foil countermeasure first used, during Operation Gomorrah in 1943?
Hamburg
German searchlights and flak radars wandered helplessly; the results were 'spectacular'.
Q 25Chaff strips are cut to what fraction of the target radar's wavelength?
Half
At that length the metal resonates and re-radiates the signal.
Q 26Which German radar was seized and brought to Britain in Operation Biting in 1942?
Würzburg
It revealed German radars used only three frequency ranges, making them easy to jam.
Q 27What 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 28Who invented the radar speed gun, working for the Automatic Signal Company in Connecticut?
Barker and Midlock
They had developed radar for the military during the Second World War.
Q 29Which nearby body was first detected by radar in 1946?
The Moon
Later measurements mapped shadowed regions near its poles.
Q 30Which lab made the first unambiguous radar contact with Venus, on 10 March 1961?
Jet Propulsion Laboratory
The echoes gave a new, precise value for the astronomical unit.