EFO Problems and Solutions

The final round of the Estonian olympiad, reached through a regional round. Archived here is the gymnasium level, in Estonian. The exams are also published in Russian, and a lower age group sits its own version.

2022

Estonia

Problems10 problemsProblemsSolutions
  • 1Kettaheidenot published
  • 2Lumevälinot published
  • 3Silindernot published
  • 4Läätsede kolmnurknot published
  • 5Jalgratasnot published
  • 6õhupüssnot published
  • 7Veeuputusnot published
  • 8Veevalajanot published
  • 9Satelliitnot published
  • 10Plaatnot published

2021

Estonia

Problems10 problemsProblemsSolutions
  • 1Lumepallnot published
  • 2Pudelnot published
  • 3Lääts ja ekraannot published
  • 4Sõit jäälnot published
  • 5Võimsusnot published
  • 6Keha keralnot published
  • 7Kolmnurknot published
  • 8Veesilindernot published
  • 9Vedelik peeglilnot published
  • 10Sirgvoolnot published

2020

Estonia

Problems10 problemsProblemsSolutions
  • 1Klaaskeranot published
  • 2Kohukesednot published
  • 3Käivitusvoolnot published
  • 4Tasakaaluliikurnot published
  • 5Gloobusnot published
  • 6Palliviskenõlvnot published
  • 7Pulgadnot published
  • 8Optiline seadenot published
  • 9õhupallidnot published
  • 10Ruutnot published

2019

Estonia

Problems10 problemsProblemsSolutions
  • 1Autodnot published
  • 2Saunauksnot published
  • 3Lennuknot published
  • 4Konveiernot published
  • 5Jääkeegelnot published
  • 6Lõksnot published
  • 73 ruutunot published
  • 8Kärbesnot published
  • 9Niit ja poolsfäärnot published
  • 10Pöörduv elektrivälinot published

2018

Estonia

Problems10 problemsProblemsSolutions
  • 1Poolitatud läätsnot published
  • 2Auk tünnisnot published
  • 3Peegelpõhinot published
  • 4Kaheosaline pendelnot published
  • 5Soojustusnot published
  • 6Pendelnot published
  • 7Takistuste tuvastaminenot published
  • 8Kerkiv õhupallnot published
  • 9Kondensaatornot published
  • 10Kaks kuulinot published

2017

Estonia

Problems10 problemsProblemsSolutions
  • 1Vastlaliugnot published
  • 2Mäenõlvnot published
  • 3Lasernot published
  • 4Korvpallnot published
  • 5Reisirongnot published
  • 6Viisnurknot published
  • 7õhupallnot published
  • 8Kaameranot published
  • 9Katusnot published
  • 10Elektronidnot published

2016

Estonia

Problems10 problemsProblemsSolutions
  • 1Soojusvahetinot published
  • 2Pidurdusnot published
  • 3Kahurikuulnot published
  • 4Silindernot published
  • 5Radoonnot published
  • 6Luupnot published
  • 7Vooluallikadnot published
  • 8Nurgapeegelnot published
  • 9Kaaternot published
  • 10Kolm kuulinot published

2015

Estonia

Problems10 problemsProblemsSolutions
  • 1õhupallnot published
  • 2Valgustaminenot published
  • 3Ujuv kuupnot published
  • 4Must kastnot published
  • 5Pallivisenot published
  • 6Lööklainenot published
  • 7Ring ja ellipsnot published
  • 8Vedrunot published
  • 9Niidiga hantelnot published
  • 10Türistornot published

2014

Estonia

Problems10 problemsProblemsSolutions
  • 1Ruudustiknot published
  • 2Viiulnot published
  • 3Paisupaaknot published
  • 4Periskoopprillidnot published
  • 5Kammidnot published
  • 6Polüspastnot published
  • 7Sportautonot published
  • 8Silindrilised anumadnot published
  • 9Traatrõngadnot published
  • 10Klaassilindernot published

2013

Estonia

Problems10 problemsProblemsSolutions
  • 1Läätsednot published
  • 2Pallnot published
  • 3Jalgratturnot published
  • 4Must kastnot published
  • 5Satelliitnot published
  • 6Tiiknot published
  • 7Mikroskoopnot published
  • 8Kauplusnot published
  • 9Jalgpalluridnot published
  • 10Kondensaatornot published

2012

Estonia

Problems10 problemsProblemsSolutions
  • 1Hõõrdkeevitusnot published
  • 2Veejuganot published
  • 3Elektriline sildnot published
  • 4Korvpallnot published
  • 5Rehvidnot published
  • 6Torunot published
  • 7Ahinot published
  • 8Liivakellnot published
  • 9Laengudnot published
  • 10šarniirnot published

2011

Estonia

Problems10 problemsProblemsSolutions
  • 1Vesinot published
  • 2Varrasnot published
  • 3Tormituulnot published
  • 4Veetorunot published
  • 5Solenoidnot published
  • 6Fotograafnot published
  • 7Rõngasnot published
  • 8Optiline süsteemnot published
  • 9Närvirakknot published
  • 10Tungraudnot published

2010

Estonia

Problems10 problemsProblemsSolutions
  • 1Sildnot published
  • 2Destillaatornot published
  • 3Päikesepaneelnot published
  • 4Hammasrattadnot published
  • 5Torunot published
  • 6Õhuhokinot published
  • 7Satelliididnot published
  • 8Jõulukaunistusnot published
  • 9Punktallikadnot published
  • 10Propellernot published

2009

Estonia

Problems10 problemsProblemsSolutions
  • 1Nürinenud kääridnot published
  • 2Kast kaubikusnot published
  • 3Kondensaatoridnot published
  • 4Rong tunnelisnot published
  • 5GPSnot published
  • 6Õhuakennot published
  • 7Konfokaalne mikroskoopnot published
  • 8Kaaternot published
  • 9Kosmoseprüginot published
  • 10Kunstinäitusnot published

2008

Estonia

Problems10 problemsProblemsSolutions
  • 1Hantelnot published
  • 2Ping-pongnot published
  • 3Toaõhknot published
  • 4Majanot published
  • 5Veealune valgusnot published
  • 6Vee keeminenot published
  • 7Traatnot published
  • 8V-torunot published
  • 9Varrasnot published
  • 10Poolnot published

2007

Estonia

Problems10 problemsProblemsSolutions
  • 1Kütteklaasnot published
  • 2Veenusnot published
  • 3Kiilnot published
  • 4Hooratasnot published
  • 5Laevnot published
  • 6Gaasidnot published
  • 7Küttekehanot published
  • 8Kuupnot published
  • 9Kumerpeegelnot published
  • 10Traatnot published

2006

Estonia

Problems10 problemsProblemsSolutions
  • 1Mõõteriistadnot published
  • 2Nõguspeegelnot published
  • 3Kadanot published
  • 4Veepüstolnot published
  • 5Kuunot published
  • 6Lendav elektronkahurnot published
  • 7Tubanot published
  • 8Soojuskiirgusnot published
  • 9Sähvatusnot published
  • 10Kuulidnot published

2005

Estonia

Problems10 problemsProblemsSolutions
  • 1Kivinot published
  • 2Ühevärviline valgusnot published
  • 3Balloonnot published
  • 4Takistidnot published
  • 5Veetünnnot published
  • 6Tsunaminot published
  • 7Mullitajanot published
  • 8Kondensaatoridnot published
  • 9Kosmosejaamnot published
  • 10Platvormnot published

2004

Estonia

Problems10 problemsProblemsSolutions
  • 1Jahipüssnot published
  • 2Veeparknot published
  • 3Kaitsmednot published
  • 4Mootorratasnot published
  • 5Mäednot published
  • 6Elektrikannnot published
  • 7Lasernot published
  • 8Nööbidnot published
  • 9Peeglidnot published
  • 10Elektrivälinot published

2003

Estonia

Problems10 problemsProblemsSolutions
  • 1Cylinder on moving belt and floor*not published
  • 2Pulling a cork from a bottle*not published
  • 3Locating focus from object and image*not published
  • 4Tide recorder maximum error*not published
  • 5Voltmeter readings sum*not published
  • 6Hydrogen balloon ballast loss*not published
  • 7Optimal flight speed problem*not published
  • 8Water barrel over curb*not published
  • 9Problem 9not published
  • 10Protons in pulsed magnetic field*not published

2002

Estonia

Problems10 problemsProblemsSolutions
  • 1Eccentric sphere on hemisphere*not published
  • 2Constructing projectile collision velocity*not published
  • 3Mirror signaling distance*not published
  • 4Diode switch signalling circuit*not published
  • 5Transient currents in RLC circuit*not published
  • 6Game car acceleration step*not published
  • 7Archive temperature cost*not published
  • 8Mass transfer in binary star*not published
  • 9Four-stroke Otto cycle efficiency*not published
  • 10Fiber ring resonator*not published

2001

Estonia

Problems10 problemsProblemsSolutions
  • 1Coin sliding on wedge*not published
  • 2Ice with sand in water*not published
  • 3Voltmeter readings with rheostat*not published
  • 4Rolling tubes down incline*not published
  • 5Freezing of pond water*not published
  • 6Magnifier field of view*not published
  • 7Braking with front wheels only*not published
  • 8Roche limit for moon*not published
  • 9Fiber-optic coupler phase shift*not published
  • 10Tungsten filament heating dynamics*not published

2000

Estonia

Problems10 problemsProblemsSolutions
  • 1Water surface under horizontal acceleration*not published
  • 2Ice with lead sinker*not published
  • 3Boat crossing river at angle*not published
  • 4Air bubble in glycerin*not published
  • 5Apparent depth of submerged object*not published
  • 6Tungsten filament operating temperature*not published
  • 7Power in a resistor network*not published
  • 8Ladder on smooth wall and floor*not published
  • 9Elastic collision of two spheres*not published
  • 10Sliding capacitor plates*not published

1999

Estonia

Problems10 problemsProblemsSolutions
  • 1Dragging rope on ground*not published
  • 2Maximum ice mass in pumped vessel*not published
  • 3Swimmer crossing a river*not published
  • 4Ideal ammeters in a resistor network*not published
  • 5Reconstruct lens plane and axis*not published
  • 6Mountain top air temperature*not published
  • 7Contact lens for near point*not published
  • 8Wire sliding on parallel rails*not published
  • 9Radiation pressure pushes bacterium*not published
  • 10Dumbbell scattering off cylinder*not published

1998

Estonia

Problems10 problemsProblemsSolutions
  • 1Sunlight spectrum to pond bottom*not published
  • 2Double weighing method*not published
  • 3Two charged particles approach*not published
  • 4Radiator temperature for colder outside*not published
  • 5Air temperature through tire valve*not published
  • 6Images in two perpendicular mirrors*not published
  • 7Car crash force graph*not published
  • 8Braking with friction and abs*not published
  • 9Hollow cylinder pulled by thread*not published
  • 10Discharging capacitor heating wire*not published