IYPT 2015, Задачи на турнира — Задача 7. Shaded Pole

Problems for the 28th IYPT 2015

Release

Released by the IOC on July 11th, 2014

Епиграф

“Would you tell me, please, which way I ought to walk from here?”
“That depends a good deal on where you want to get to,” said the Cat.
Lewis Carroll

Условие

Place a non-ferromagnetic metal disk over an electromagnet powered by an AC supply. The disk will be repelled, but not rotated. However, if a non-ferromagnetic metal sheet is partially inserted between the electromagnet and the disk, the disk will rotate. Investigate the phenomenon.

Sketch: a metal disk on a stand with a curved arrow showing rotation, above a coil (electromagnet) connected to a source marked with a sine symbol and AC; a flat metal sheet is partially inserted between the coil and the disk.

Решение

Внимание: Непълно решение

Това е открита изследователска задача — официални решения не се публикуват.

Автори

Authors: Alan Allinson, John Balcombe, Roderick Bloem, Artsiom Bury, Samuel Byland, Nikita Chernikov, Lars Gislén, Łukasz Gładczuk, Timotheus Hell, Mihály Hömöstrei, Stanislav Krasulin, Valentin Lobyshev, Ilya Martchenko, Reza Montazeri Namin, Stanisław Świdwiński, Boris Vavrík, Evgeny Yunosov.

Problem selection committee: John Balcombe, Samuel Byland, Ilya Martchenko.

Epigraph selected by Evgeny Yunosov.

Оригинал в Архива: 2015.pdf