5H15.40: Iron Filings Around a Solenoid

5h1510iron_filings_around_a_wire 5h1540iron_filings_around_a_solenoid

Video: Watch this demo

Instructor’s video

Description: A solenoid is wound through a piece of plexiglass for use with iron filings on the overhead projector.
The iron filings align themselves with the magnetic field caused by the current in the solenoid. (Also see 5H15.10)


  • Large DC power supply
  • Solenoid Piece
  • Iron Filings
  • 4 Banana plug cables
  • Overhead Projector

Setup Procedure:

  1. Connect the solenoid to the power supply using two cables in parallel per terminal.
  2. Test to make sure the apparatus works.
  3. Place on the overhead projector and focus it.
  4. When the professor is done, dump the filings on a piece a paper and then pour them back into the jar.

Demonstration Procedure:

  1. Turn on the overhead projector.
  2. Turn on the power supply.
  3. Sprinkle iron filings on the solenoid. You may tap the piece a little to help them align. Note that the filings align in the direction of the magnetic field created around the solenoid.
  4. When finished, turn off the power supply.