https://www.physlab-wiki.com/ 2026-04-24T22:30:59+00:00 https://www.physlab-wiki.com/ https://www.physlab-wiki.com/lib/tpl/UChicago/images/favicon.ico text/html 2021-09-15T17:30:57+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_materials/barkhausen_effect?rev=1631741457&do=diff Barkhausen Effect A magnetic field is gradually introduced to a piece ferromagnetic material inside a coil. The growth of magnetic domains inside the ferromagnet induces a signal in the coil which can be heard using an amplifier and speaker. J3, speaker in J1 text/html 2021-09-15T17:31:16+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_materials/ferromagnetic_hysteresis?rev=1631741476&do=diff Ferromagnetic Hysteresis A ferromagnetic material is placed inside the secondary coil of a transformer which is driven by a sine wave generator. A simple external circuit allows one to measure the integrated current through the secondary as well as the current through the primary which are measures of the magnetic field strength (B) and the magnetic flux density (H) respectively. Using an oscilloscope in xy-mode to observe these two quantities yields a classic hysteresis curve which changes … text/html 2024-02-22T16:54:48+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_materials/meissner_effect_levitation?rev=1708638888&do=diff Meissner Effect Levitation Owing to the Meissner effect, a small permanent magnet is seen to levitate above a high-temperature superconductor that has been cooled with liquid nitrogen. A video camera is used to project a close-up view on the wall or screen for the class to see. Apparatus is available for measuring the resistance and temperature of the superconductor. text/html 2025-07-22T10:14:55+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_materials/paramagnetism_of_liquid_oxygen?rev=1753193695&do=diff Paramagnetism of Liquid Oxygen Liquid oxygen forms and drips from the surface of a metallic container filled with liquid nitrogen. Due to its paramagnetic behavior, the liquid oxygen will stick to the poles of a permanent magnet. Note: requires quite a bit of liquid nitrogen. text/html 2024-02-22T16:56:54+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_materials/superconductor_train?rev=1708639014&do=diff Superconductor Train A styrofoam model of a train contains a piece of a type-2 superconducting material. Liquid nitrogen is poured into the train as it is held a small distance above a track which is permanently magnetic, cooling the superconductor and trapping the magnetic flux that is present in it. The track is made from three rows of permanent, high-strength magnets which, in cross-section, are oriented N-S-N. Once cooled, the train will levitate and remain aligned with the track.