http://physlab-wiki.com/ 2026-04-30T01:19:44+00:00 http://physlab-wiki.com/ http://physlab-wiki.com/lib/tpl/UChicago/images/favicon.ico text/html 2021-09-15T17:34:43+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/crt_electron_beam_deflection_with_a_magnetic_field?rev=1631741683&do=diff CRT Electron Beam Deflection with a Magnetic Field A cathode ray tube is used to show the deflection of an electron beam in the presence of a magnetic field generated by Helmholtz coils or a permanent magnet. J3, J4, A4 PIRA DCS 5H30.10 text/html 2021-09-15T17:35:45+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/e_over_m?rev=1631741745&do=diff e over m An narrow electron beam is generated inside a glass bulb. Ionization of a rarefied gas inside the bulb makes the beam visible. When an external magnetic field is applied via a pair of Helmholtz coils the electron beam assumes a circular path. The strength of the magnetic field, the electric accelerating potential, and the curvature of the electron beam are sufficient to calculate the ratio of the electric charge to the mass of the electron. text/html 2021-09-15T17:36:05+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/force_on_a_solenoid_core?rev=1631741765&do=diff Force on a Solenoid Core A large, heavy iron rod is placed partially inside a coil. When a large current is applied to the coil the ferromagnet is violently drawn in. J3, A4 PIRA DCS 5H25.25 text/html 2024-02-22T16:50:52+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/forces_between_current-carrying_wires?rev=1708638652&do=diff Forces Between Current-Carrying Wires Two large wires carrying approximately 100 A AC attract when their currents run parallel and repel when anti-parallel. Setup Don't run for more than 2-3 seconds at a time, under risk of smoke, sparks and fire. Make sure all connections are good, as it's the most common source of trouble. text/html 2021-09-15T17:36:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/magnetic_accelerator?rev=1631741800&do=diff Magnetic Accelerator When a ball is separated from the group and allowed to roll down the track it accelerates due to gravitational and magnetic forces. A ball on the opposite side is ejected with more velocity that the change from gravitational potential to kinetic energy alone can provide. text/html 2024-02-22T16:51:46+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/magnetic_deflection_of_a_current-carrying_wire?rev=1708638706&do=diff Magnetic Deflection of a Current-Carrying Wire Current in either direction is applied to a wire hanging freely in the field of a permanent magnet causing the wire to deflect Setup Use a power supply that can go up to at least 3 A for a nice jump of the wire. text/html 2021-09-15T17:37:21+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/magnetic_field_around_a_wire_with_a_compass?rev=1631741841&do=diff Magnetic Field Around a Wire With a Compass The magnetic field generated by a long wire carrying a DC current is investigated with a large compass. J3, A4 PIRA DCS 5H10.20 text/html 2021-09-15T17:37:35+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/magnetic_field_lines_for_a_bar_magnet?rev=1631741855&do=diff Magnetic Field Lines for a Bar Magnet One or more bar magnets are placed beneath a glass plate. When iron filings are sprinkled onto the plate they align with the magnetic field due to the bar magnet(s). The patterns created by the filings are projected onto the lecture hall wall. Small, transparent compasses are also available to show the direction of the field lines. text/html 2021-09-15T17:37:52+00:00 Anonymous (anonymous@undisclosed.example.com) http://physlab-wiki.com/physicsdemos/electricity_and_magnetism/magnetic_fields_and_forces/magnetic_field_lines_for_various_current_geometries?rev=1631741872&do=diff Magnetic Field Lines for Various Current Geometries Solenoid, loop, and single wire current geometries are present on a single transparent plate. When iron filings are sprinkled onto the plate they align with the magnetic field due to the currents. The patterns created by the filings are projected onto the lecture hall wall. Small, transparent compasses are also available to show the direction of the field lines.