1011 past contests
Topic 8 · Comparing half-lives of two radioisotopes from decay data
Topic 8 · Estimating nuclear size from the mass number using the nuclear radius formula
Topic 26 · Compton wavelength of the deuteron
Topic 49 · Angle to the first dark ring of an airy diffraction pattern from a circular aperture
Topic 53 · Initial speed needed for a later-dropped object to land simultaneously with an earlier one
Topic 26 · Wien's displacement law: peak frequency of blackbody radiation
Topic 34 · Ballistic pendulum: greatest swing height from a perfectly inelastic collision
Topic 49 · The abbe number as a measure of optical glass dispersion
Topic 22 · De broglie wavelength
Topic 9 · Riddle: radius of curvature
Topic 15 · Doping and charge neutrality in p-type and n-type semiconductors (true/false)
Topic 9 · The wavelength range of visible light (true/false)
Topic 39 · Problem of the day: solenoid magnetic field, flux, and induced emf from a rotating loop
Topic 43 · Voltage across a capacitor from its stored energy and capacitance
Topic 26 · Photon energy from its frequency, expressed in electron volts
Topic 10 · Work done by an ideal gas in an isobaric expansion
Topic 63 · Resonant frequencies of an open and closed organ pipe of the same length
Topic 11 · Balancing a uniform meter stick using moments
Topic 28 · Riddle: stefan's law
Topic 1 · Relationship between the signs of velocity, acceleration and speed (true/false)