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Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography


Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.

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 Electric Fields And Potential
 Current and Resistance
 Electromotive Force And Current
 DC Circuits
 Magnetic Materials
 Magnet collection
  video  - Magnetic Fields w/ Iron Filings
  video  - Magnetic Fields w/ Matrix of Iron Rods
  video  - Magnetic Fields Associated with Current Carrying Wires 1
  video  - Magnetic Fields Associated with Current Carrying Wires 2
  video  - Solenoid w/ Iron core
  video  - Magnetic Deflection of an Electron Beam
  video  - e/m Tube Lorentz Force Demonstrator
 Magnetohydrodynamic Motor
  video  - Forces Between Current Carrying Wires
  video  - Vibrating Lamp Filament
  video  - Force on a Current Carrying Wire in a Magnetic Field
 Hall Effect
  video  - Galvanometer Movement
 Complex Circuits
 Semiconductors And Tubes
 Transmission Lines and Antennas

 video  - Solenoid w/ Iron core


To demonstrate ferromagnetic properties of Iron.


centered image
  DEMO VIDEO DOWNLOAD w/ sound / 1920x1080 / 24.19Mb/s / 365MB size  

  DEMO VIDEO DOWNLOAD w/ sound / 854x480 / 5.69Mb/s / 86MB size  

We have two sets of solenoid with iron core. The homemade green solenoid shown in the first two images and a newer red one in the third image.

  • Insert the Iron core halfway into the solenoid. Turn on the switch and observe the core movement. Notice the Iron rod gets attracted toward the center of the solenoid coil. Turn off the switch immediately after that. Leaving it on will result in damage to the solenoid, the battery or both.
  • Place the solenoid and iron core between two aluminum plates. This is an example of a "double chime" door bell. When the core is accelerated it will produce noticeable hammering/chime sound hitting the plates.
  • Similar experiments can be done with our newer red solenoid.


The red solenoid is made by Ginsberg Scientific part# 7-1850-1. A black plastic tube of ID=0.80" is wrapped with copper wire to form a coil of 1-1/4" dia. by 4-1/4" long. The coil has 22 turns per inch, times 3 layers per turn to give a total of 300 turns. The iron core is 0.75" dia. by 6" long.