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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
  video  - Back EMF in an Inductor
  video  - LR Circuit w/ Function Generator
 LR Circuit w/ Battery
  video  - Ringing LC Circuit w/ Function Generator
 Ringing LC Circuit w/ Battery
 Complex Circuits
 Semiconductors And Tubes
 Transmission Lines and Antennas

Ringing LC Circuit w/ Battery


To illustrate the properties of a simple LC circuit with battery during charging or discharging. First image shows the general setup.


Charging LC Circuit: Starting with the switch in the "discharge" position, up toward the inductor, toggle switch down to "charging", then back up to "discharging". As shown in second image below, blue trace (Channel-2) measures voltage drop across capacitor, yellow trace (Channel-1) measures voltage drop across inductor. The frequency of the ringing is calculated via: f = 1 / 2πLC

Discharging LC Circuit: Effectively similar to the charging situation, ringing in the LC circuit is observed (not shown).


  • C=6.4nF or 2.2nF, L=0.5H, RL=84.2Ω
  • R=56kΩ can be placed in series to show overdamped circuit