5K10.20 Induction Coil and Magnet


Faraday's law, Lenz' law


A permanent magnet changes the flux through coil, generating a voltage that can be read by an analog voltmeter (you can pretend it's a galvanometer).



  • [1] Coil
  • [1] Permanent magnet
  • [1] Analog voltmeter
  • [1] (Optional) Windows laptop with LabVIEW
  • [1] (Optional) NI USB-6212 DAQ

Classroom Assembly

  1. Connect the voltmeter to the coil or to the DAQ and computer.
  2. (For computer data collection) Load the voltage measurement VI on the computer.


  1. (For computer data collection) Connect the laptop to the room's projector and start the voltage measurement VI.
  2. Move the magnet quickly towards the coil and stop.
  3. Move the magnet quickly away from the magnet.
  4. Flip the magnet pole and repeat steps 1-2.
  5. For maximum flux change, hold the magnet close to the coil and quickly flick your wrist to reverse the poles.
  6. (For computer data collection) Stop the voltage measurement VI.


Additional Resources


  • PIRA 5K10.20


  • Don't attempt this at home!

Last revised

  • 2019


  • The usual demo laptop takes about 5 minutes to run smoothly from cold boot.
  • If running the computer, on the day before, check that all Windows updates have been applied.

Related AV

Related demos

  • ?


If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.