1011 past contests
Topic 6 · Ranking the speed of yellow light in different media (vacuum fastest, glass slowest)
Topic 13 · Converting volt-seconds to si base units
Topic 50 · Launch angle for maximum projectile range (negligible air resistance)
Topic 33 · Water mass to remove to reach a target heat capacity
Topic 33 · Water mass to add to reach a target heat capacity
Topic 33 · Heat capacity of a given mass of water from its specific heat capacity
Topic 48 · Refractive index of a glass block from its thickness and an object's apparent depth
Topic 48 · Apparent depth of a submerged coin from real depth and refractive index
Topic 48 · Real depth of a submerged object from its apparent depth and the medium's refractive index
Topic 64 · Riddle: refraction at a boundary between media with different wave speeds
Topic 15 · Intrinsic semiconductors have equal electron and hole concentrations (true/false)
Topic 15 · P-type semiconductors have excess holes, not excess protons (true/false)
Topic 15 · N-type semiconductors remain electrically neutral overall despite excess electrons (true/false)
Topic 9 · Paraxial rays parallel to the axis converge at the principal focus, midway between $C$ and the pole (true/false)
Topic 51 · Average velocity from a displacement that reverses direction, over a given time
Topic 45 · Focal length of a spherical mirror, and concave-mirror image/magnification properties (true/false)
Topic 12 · The velocity ratio of a simple machine as effort-to-load distance
Topic 40 · Diffusion as the cause of the depletion layer in an unbiased p-n junction
Topic 40 · Reverse bias widening a p-n junction's depletion region
Topic 40 · The depletion layer separating the p and n regions of a p-n junction