Sub-topic 1
2024 · National Preliminary
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Optical power of a lens: true/false
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Sub-topic 2
2026 · National Quarterfinal
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Focal length and power of a compound (contact) lens system
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Sub-topic 3
2026 · National One-Eighth
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Magnification produced by a converging lens (virtual image)
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Sub-topic 4
2017 · National Quarterfinal
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Focal length of a thin plano-concave lens from its radius of curvature and refractive index
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Sub-topic 5
2013 · National Preliminary
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Riddle: the converging (convex) lens
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Sub-topic 6
2013 · National Preliminary
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Focal length of a lens from object distance when image forms at the object's location
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Sub-topic 7
2013 · National Quarterfinal
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Diverging lens corrects nearsightedness (myopia)
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Sub-topic 8
2013 · National Quarterfinal
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Cylindrical lens corrects astigmatism
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Sub-topic 9
2013 · National Quarterfinal
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Converging lens corrects farsightedness (hyperopia)
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Sub-topic 10
2013 · National Quarterfinal
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Lens focal length depends on both radii and refractive index, not just the radius (true/false)
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Sub-topic 11
2013 · National Quarterfinal
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Diverging lens corrects nearsightedness (repeat)
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Sub-topic 12
2013 · National Quarterfinal
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Magnification of a convex lens when the object is within the focal length
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Sub-topic 13
2013 · National Quarterfinal
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Object distance for a given magnification with a converging lens
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Sub-topic 14
2013 · National Quarterfinal
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Image distance for a given magnification with a converging lens
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Sub-topic 15
2014 · National Final
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Problem of the day: choosing lens type and focal length for a long-sighted (hyperopic) reader
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Sub-topic 16
2017 · National Quarterfinal
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Focal length of a thin plano-convex lens from its radius and refractive index (three variants)
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Sub-topic 17
2018 · National Preliminary
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Effective focal length of two thin lenses in contact (opposite-sign focal lengths)
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Sub-topic 18
2018 · National Preliminary
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Effective focal length of two identical thin lenses in contact
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Sub-topic 19
2018 · National Preliminary
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Effective focal length of two thin lenses in contact (a converging and diverging lens)
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Sub-topic 20
2018 · National Preliminary
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Focal length of a converging lens from an object distance and a threefold virtual, upright image distance
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Sub-topic 21
2020 · National One-Eighth
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Riddle: the lensmaker's formula relating lens power to surface radii
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Sub-topic 22
2022 · National Preliminary
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True or false: max magnification in a compound microscope occurs when the final image coincides with the objective lens
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Sub-topic 23
2023 · National One-Eighth
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Lens power: reciprocal of focal length, combined lenses, and sign convention (true/false)
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